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Publication Series - NCHRP Synthesis Report
The National Cooperative Highway Research Program’s (NCHRP's) Synthesis of Highway Practice series reports on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each report in the series provides a compendium of the best knowledge available on those measures found to be the most successful in resolving specific problems.
Items found: 354
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381 - Falling Weight Deflectometer Usage
10/30/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 381: Falling Weight Deflectometer Usage examines usage by state departments of transport of the falling weight deflectometer (FWD) to measure pavement deflections in response to a stationary dynamic load, similar to a passing wheel load. [More] | |
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379 - Selection and Evaluation of Alternative Contracting Methods to Accelerate Project Completion
10/24/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 379: Selection and Evaluation of Alternative Contracting Methods to Accelerate Project Completion explores the process for selection of alternative contracting methods that can potentially accelerate project completion. The report also examines factors associated with selecting one type of alternative contracting technique over another. [More] | |
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378 - State Highway Cost Allocation Studies
9/29/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 378: State Highway Cost Allocation Studies examines the history and evolution of highway cost allocation study practice and explores the current state of the practice. [More] | |
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377 - Compilation of Public Opinion Data on Tolls and Road Pricing
6/6/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 377: Compilation of Public Opinion Data on Tolls and Road Pricing explores how the public feels about tolls and road pricing, examines public opinion concerning charging for the use of roads, and highlights factors associated with the acceptance or rejection of road pricing. [More] | |
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376 - Quality Assurance in Design-Build Projects
8/4/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 376: Quality Assurance in Design-Build Projects examines how state transportation agencies have successfully approached quality assurance for design-build, including in procurement, design, construction, and post-construction operations and maintenance. [More] | |
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375 - Bridge Inspection Practices
3/14/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 375: Bridge Inspection Practices examines bridge inspection practices in the United States and selected foreign countries. The report explores inspection personnel (staff titles and functions, qualifications, training and certification, inspection teams, and the assignment of teams to bridges), inspection types (focus, methods, and frequency), and inspection quality control and quality assurance. The report also reviews the uses agencies make of information gathered from bridge inspections, what triggers repairs, and plans for future development of inspection programs. [More] | |
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373 - Multi-Disciplinary Teams in Context-Sensitive Solutions
2/14/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 373: Multi-Disciplinary Teams in Context-Sensitive Solutions explores inclusion of multiple perspectives and disciplines in the decision-making process associated with developing transportation solutions that improve the quality of life for the communities being served by transportation agencies. [More] | |
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372 - Emerging Technologies for Construction Delivery
2/12/2008
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 372: Emerging Technologies for Construction Delivery explores the use of five emerging technologies for transportation construction projects: global positioning systems for layout, machine guidance, and quantity tracking; handheld computers for construction records; automated temperature tracking for concrete maturity monitoring; four-dimensional computer-aided drafting modeling for constructability analysis and improved communications; and web-based video cameras for remote project monitoring. [More] | |
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371 - Managing Selected Transportation Assets: Signals, Lighting, Signs, Pavement Markings, Culverts, and Sidewalks
12/26/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 371: Managing Selected Transportation Assets: Signals, Lighting, Signs, Pavement Markings, Culverts, and Sidewalks explores the state of the practice for managing transportation infrastructure assets other than pavements and bridges, and documents gaps in knowledge and areas in need of potential further study. [More] | |
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370 - Animal-Vehicle Collision Data Collection
11/30/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 370: Animal-Vehicle Collision Data Collection examines the extent to which data from animal–vehicle collision accident reports and animal carcass counts are collected, analyzed, and used throughout the United States and Canada. [More] | |
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369 - State DOT Crash Reconstruction Practices
8/8/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 369: State DOT Crash Reconstruction Practices examines the extent of crash reconstruction undertaken by state departments of transportation (DOTs) and the level of expertise available to perform the tasks. In addition, the report explores the extent to which crash reconstructions are used by state DOTs to improve highway safety. [More] | |
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368 - Cone Penetrating Testing
11/1/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 368: Cone Penetrating Testing explores the current practices of departments of transportation associated with cone penetration testing (CPT). The report examines cone penetrometer equipment options; field testing procedures; CPT data presentation and geostratigraphic profiling; CPT evaluation of soil engineering parameters and properties; CPT for deep foundations, pilings, shallow foundations, and embankments; and CPT use in ground modifications and difficult ground conditions. [More] | |
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367 - Technologies for Improving Safety Data
8/28/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Syntheses 367: Technologies for Improving Safety Data explores new technologies for the acquisition, processing, and overall management of crash, roadway inventory, and traffic operations data. The report examines the current state-of-the-practice and state-of-the-art use of technologies for efficient and effective collection and maintenance of data for highway safety analysis. [More] | |
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366 - Tribal Transportation Programs
5/29/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 366: Tribal Transportation Programs explores innovations and model practices among tribal transportation programs. The report also examines the history, and legal and administrative evolution, of tribal transportation programs within the larger context of issues of tribal sovereignty and relationships with federal, state, and local governments, and local and regional planning agencies. [More] | |
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365 - Preserving and Using Institutional Memory Through Knowledge Management Practices
3/5/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 365: Preserving and Using Institutional Memory through Knowledge Management Practices explores practices regarding the preservation and use of institutional memory through the knowledge management practices of United States and Canadian transportation agencies. The report examines practices for the effective organization, management, and transmission of materials, knowledge, and resources that are in the unique possession of individual offices and employees. [More] | |
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364 - Estimating Toll Road Demand and Revenue
4/11/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Syntheses 364: Estimating Toll Road Demand and Revenue examines the state of the practice for forecasting demand and revenues for toll roads in the United States. The report explores the models that are used to forecast the demand for travel and the application of these models to project revenues as a function of demand estimates. [More] | |
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363 - Control of Invasive Species
2/12/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 363: Control of Invasive Species explores the extent to which state departments of transportation are identifying actions that affect the spread of invasive species, preventing introduction, tracking status and locations of “invasives” in a timely and ongoing manner, controlling found populations, restoring invaded habitats, conducting research, and sharing lessons learned. The report documents successful practices and lessons learned. It also synthesizes the state of the practice in developing Integrated (Roadside) Vegetation Management, along with physical, chemical, biological, and cultural control mechanisms. [More] | |
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362 - Training Programs, Processes, Policies, and Practices
1/16/2007
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 362: Training Programs, Processes, Policies, and Practices examines program components required to have a sound set of policies, processes, and procedures for planning, developing, implementing, funding, and evaluating state department of transportation training, development, and education programs. [More] | |
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361 - Visualization for Project Development
10/31/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 361: Visualization for Project Development explores the visual representation of proposed alternatives and improvements and their associated effects on the existing surroundings. The report examines the best practices and experiences within transportation agencies that are developing and incorporating visualization into the project development process. [More] | |
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360 - Rock-Socketed Shafts for Highway Structure Foundations
9/1/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 360: Rock-Socketed Shafts for Highway Structure Foundations explores current practices pertaining to each step of the design process, along with the limitations; identifies emerging and promising technologies; examines the principal challenges in advancing the state of the practice; and investigates future developments and potential improvements in the use and design of rock-socketed shafts. [More] | |
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359 - Bridge Rating Practices and Policies for Overweight Vehicles
8/11/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 359: Bridge Rating Practices and Policies for Overweight Vehicles explores overweight vehicle permit processes. The report includes information on state and provincial bridge rating systems, bridge evaluation practices, and permit policies as they relate to overweight and oversize vehicles. The report is designed to help in the understanding of the reasons for nonuniform permitting practices. The report reviews specifications, software types, treatment of nonstandard configurations, and allowance for in-place dead loads; processes of permit review; and personnel assigned to permit review. [More] | |
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358 - Statewide Travel Forecasting Models
8/8/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 358: Statewide Travel Forecasting Models examines statewide travel forecasting models designed to address planning needs and provide forecasts for statewide transportation, including passenger vehicle and freight movements. The report explores the types and purposes of models being used, integration of state and urban models, data requirements, computer needs, resources (including time, funding, training, and staff), limitations, and overall benefits. The report includes five case studies, two that focus on passenger components, two on freight components, and one on both passenger and freight. [More] | |
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357 - Use of Geophysics for Transportation Projects
5/16/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 357: Use of Geophysics for Transportation Projects examines the state of the practice regarding the use of geophysics for transportation projects. The report focuses on who is using geophysics and why, which methods and applications are the most commonly used, the use of in-house expertise compared with contracting private consultants, and how geophysical service contracts are procured and implemented. [More] | |
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356 - Pavement Markings--Design and Typical Layout Details
6/12/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 356: Pavement Markings—Design and Typical Layout Details identifies variations in pavement marking designs, practices, and policies, as provided by 48 of 50 state departments of transportation, and transportation agencies from the District of Columbia, Puerto Rico and four cities. [More] | |
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355 - Transportation Technology Transfer: Successes, Challenges, and Needs
3/24/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 355: Transportation Technology Transfer: Successes, Challenges, and Needs explores the use of technology transfer practices in the highway transportation community. The report documents successful practices, discusses challenges encountered, and identifies the needs of those responsible for sponsoring, facilitating, and conducting technology transfer activities and processes. [More] | |
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354 - Inspection and Management of Bridges with Fracture-Critical Details
2/16/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 354: Inspection and Management of Bridges with Fracture-Critical Details explores the inspection and maintenance of bridges with fracture-critical members (FCMs), as defined in the American Association of State Highway and Transportation Officials’ Load and Resistance Factor Design (LRFD) Bridge Design Specifications. The report identifies gaps in literature related to the subject; determines practices and problems with how bridge owners define, identify, document, inspect, and manage bridges with fracture-critical details; and identifies specific research needs. Among the areas examined in the report are inspection frequencies and procedures; methods for calculating remaining fatigue life; qualification, availability, and training of inspectors; cost of inspection programs; instances where inspection programs prevented failures; retrofit techniques; fabrication methods and inspections; and experience with fracture-critical members fractures and problems details. [More] | |
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353 - Inspection and Maintenance of Bridge Stay Cable Systems
2/7/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 353: Inspection and Maintenance of Bridge Stay Cable Systems identifies and explains various inspection and maintenance techniques for bridge stay cable systems. It discusses both short- and long-term approaches. The report information on methods for inspections and assessments, including nondestructive testing and evaluation procedures; repair and retrofit; methods for control of cable vibrations, including rain–wind vibrations; stay cable fatigue and failure; effectiveness of various inspection and repair methods; limitations of available technologies; and trends and recommendations for future study. [More] | |
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352 - Value Engineering Applications in Transportation
12/19/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 352: Value Engineering Applications in Transportation examines the current value engineering (VE) practices of highway transportation agencies in the United States and Canada. Value engineering (VE) is the systematic review of a project, product, or process to improve performance, quality, and/or life-cycle cost by an independent multidisciplinary team of specialists. The report identifies the reported best practices, key strengths, and challenges of current VE study processes and agency programs, and offers guidance on applying and improving the effectiveness of VE in projects and programs. [More] | |
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351 - Access Rights
11/30/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 351 examines issues involved in acquiring access rights along roadways other than freeways. The report documents the state of the practice with the intent to limit the amount of access to the roadway for the purpose of managing highway safety and mobility. The report documents successful practices and current policies, legal and real estate literature, and other publications that address this subject. [More] | |
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350 - Crash Records Systems
2/2/2006
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 350: Crash Records Systems examines crash records systems practices and programs as applied to highway and traffic safety. The report covers crash data collection, crash processing and management, and data linkages for reporting and analysis. While no single comprehensive system examples are identified in the report, many examples of one or more successful components were found to address the needs of three groups of stakeholders—data collectors, data managers, and data users. The report also contains information about lessons learned from examples of successful systems, addressing the needs and concerns of stakeholders. [More] | |
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349 - Developing Transportation Agency Leaders
9/26/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 349: Developing Transportation Agency Leaders examines practices and innovative approaches that address the development of transportation leadership in today’s work environment. The report covers demographics, recruitment and retention, leadership training, and succession management. [More] | |
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348 - Improving the Safety of Older Road Users
10/17/2005
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 348: Improving the Safety of Older Road Users examines programs and policies in place across the country to improve the safety and mobility of older road users. The report documents a range of strategies and related programs under way in roadway engineering, driver licensing, public information and education, and enforcement and adjudication. [More] | |
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347 - Managing Archaeological Investigations
8/22/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 347: Managing Archaeological Investigations addresses practices that improve archaeological investigations by both streamlining the overall transportation project delivery process and enhancing the stewardship of archaeological resources. The report examines practices that improve and maintain good communication and coordination at all stages of transportation programs, including that between agencies and Native Americans and efforts at public outreach. It also reviews internal state department of transportation (DOT) business practices, and examines effective and innovative practices for complying with Section 106 of the National Historic Preservation Act, the National Environmental Policy Act, and project design. The synthesis also examines pre-project planning efforts, including programmatic agreements, treatment guidance and specifications on specific archaeological resources, creative mitigation, and effective collection methods. [More] | |
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346 - State Construction Quality Assurance Programs
6/28/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 346: State Construction Quality Assurance Programs examines current quality assurance practices of state and federal departments of transportation with regard to highway materials and construction. The report focuses on the strategies and practices used by agencies to ensure quality. [More] | |
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345 - Steel Bridge Erection Practices
6/1/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 345: Steel Bridge Erection Practices examines steel bridge erection practices for I-girder, tub-girder, and box-girder bridges; particularly curved, skewed, and staged structures. The report focuses on the impact of design and analysis practices on erection; methods used to predict erection deflections as a function of bridge type and complexity; shop-assembly practices and alternate methods of ensuring properly assembled geometry; stability issues; field connection practices; examples of structures in which erection practices have caused problems; owner requirements for erection procedures, implementation of requirements, and the impact of procedures on the quality of erection; and current and proposed research. [More] | |
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344 - Winter Highway Operations
6/13/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 344: Winter Highway Operations examines changes that occurred between 1994 and 2004 to practices and strategies used to control the impacts of winter weather on the safe and efficient movement of traffic. [More] | |
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343 - Management of Disadvantaged Business Enterprise Issues in Construction Contracting
5/12/2005
TRB National Cooperative Highway Research Program (NCHRP) Synthesis 343: Management of Disadvantaged Business Enterprise Issues in Construction Contracting examines state transportation agencies’ (STA's) various approaches to implementation of DBE regulations relating to bidder’s lists; prompt payment; return of retainage; actual achievements, including accounting and reporting procedures; good faith efforts; and compliance, including substitutions, fraud, and commercially useful functions. The report also includes information on construction and construction management contracts, design–build projects, master contracts (indefinite delivery/indefinite quantity, services on demand, and task ordering), pass-through to local agencies, and STA performance measures. [More] | |
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342 - Chip Seal Best Practices
4/22/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 342: Chip Seal Best Practices examines ways to assist in the development and implementation of pavement preservation programs by identifying the benefits of using chip seal as part of a preventive maintenance program and by highlighting advanced chip seal programs in use around the world. The report includes approximately 40 best practices in the areas of chip seal design methods, contract administration, equipment practices, construction practices, and performance measures. According to the report, the increased use of chip seals for maintenance can be a successful, cost-effective way of using preventive maintenance to preserve both low-volume and higher-volume pavements. [More] | |
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341 - Integrated Roadside Vegetation Management
4/14/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 341: Integrated Roadside Vegetation Management examines the incorporation of integrated roadside vegetation management decision-making processes into highway project planning, design, construction, and maintenance. The report also documents existing roadside vegetation management research and practice. [More] | |
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340 - Convertible Roadways and Lanes
2/16/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 340: Convertible Roadways and Lanes examines the characteristics and operational requirements, costs, and benefits of convertible roadways and lanes. [More] | |
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339 - Centerline Rumble Strips
4/5/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 339: Centerline Rumble Strips (CLRS) examines current design, installation, configuration, dimension, and visibility issues associated with CLRS. The report addresses the need for guidance on warrants, benefits, successful practices, and concerns such as external noise and the reduced visibility of centerline striping material. Also addressed are pavement deterioration, ice buildup in the grooves, adverse impact on emergency vehicles, and the effect of CLRS on bicyclists. Particular attention was paid to available before-and-after CLRS installation crash data to document the safety aspects of CLRS and the availability of policies, guidelines, warrants, and costs regarding their use and design. [More] | |
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338 - Thin and Ultra-Thin Whitetopping
2/4/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 338: Thin and Ultra-Thin Whitetopping summarizes available information to document how state departments of transportation and others are currently using thin and ultra-thin whitetopping overlays among various pavement rehabilitation alternatives. The report covers all stages of the proper application of whitetopping overlays, including project selection, design, materials selection, construction, maintenance, and eventual rehabilitation or replacement. [More] | |
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337 - Cooperative Agreements for Corridor Management
2/15/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 337: Cooperative Agreements for Corridor Management examines the current state of practice in developing and implementing cooperative agreements for corridor management, elements of such agreements, and successful practices or lessons learned. The report focuses on cooperative agreements between two or more government agencies or between public and private entities that address land use and transportation linkages. [More] | |
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336 - Road Safety Audits
12/15/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 336: Road Safety Audits examines the state of the practice of road safety audit (RSA) and road safety audit review applications for U.S. states and Canadian provinces. This synthesis also reviews international RSA practices. RSAs were first introduced in the United Kingdom more than 20 years ago and have been applied in New Zealand and Australia since the 1990s. [More] | |
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335 - Pavement Management Applications Using Geographic Information Systems
12/14/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 335: Pavement Management Applications Using Geographic Information Systems examines the state of the practice and knowledge of pavement management systems (PMS) using geographic information systems (GIS) and other spatial technologies, and discusses how the technologies have been combined to enhance the highway management process. The synthesis reviews the principal issues related to PMS data collection, integration, management, and dissemination; applications of spatial technologies for map generation and PMS spatial analysis; and implementation-related issues, including approaches used for integrating PMS and GIS and the different tools used to support pavement management decisions. [More] | |
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334 - Automated Pavement Distress Collection Techniques
11/15/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 334: Automated Pavement Distress Collection Techniques examines highway community practice and research and development efforts in the automated collection and processing of pavement condition data techniques typically used in network-level pavement management. The scope of the study covered all phases of automated pavement data collection and processing for pavement surface distress, pavement ride quality, rut-depth measurements, and joint-faulting measurements. Included in the scope were technologies employed, contracting issues, quality assurance, costs and benefits of automated techniques, monitoring frequencies and sampling protocols in use, degree of adoption of national standards for data collection, and contrast between the state of the art and the state of the practice. [More] | |
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333 - Concrete Bridge Deck Performance
11/12/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 333: Concrete Bridge Deck Performance examines previous and current design and construction practices designed to improve the performance of bridge decks. Topics covered in this synthesis include factors that contribute to the durability of concrete bridge decks; performance of various types of deck protection strategies; lessons learned and the current state of the practice in design, construction, and maintenance of concrete bridge decks; available comparative analysis of the effects of using different methods and materials; specific reports of successes and failures; sample design and construction specifications; and more. [More] | |
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332 - Access Management on Crossroads in the Vicinity of Interchanges
10/19/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 332: Access Management on Crossroads in the Vicinity of Interchanges examines current practices relating to access location and design on crossroads in the vicinity of interchanges. It identifies standards and strategies used on new interchanges and on the retrofit of existing interchanges. [More] | |
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331 - Statewide Highway Letting Program Management
10/5/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 331: Statewide Highway Letting Program Management summarizes available information on statewide highway letting programs, which are defined as a set of highway projects in advanced stages of design that have a target date for construction bid. This synthesis identifies those approaches, tools, and techniques used by state highway agencies (SHAs) in the management of letting programs; evaluates changes that influence letting schedules; identifies the impact of issues relevant to contract award that may influence the outcomes of specific lettings; and assesses SHA interest in data sharing initiatives relative to letting program management. [More] | |
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330 - Public Benefits of Highway System Preservation and Maintenance
8/24/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 330: Public Benefits of Highway System Preservation and Maintenance examines the current practices for identifying, measuring, and articulating the public benefits of highway system maintenance and operation, and of communicating those benefits that are understandable and meaningful to stakeholders—road users, elected officials, and others who have an interest in the system’s performance. [More] | |
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329 - Integrating Tourism and Recreation Travel with Transportation Planning and Project Delivery
6/2/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 329: Integrating Tourism and Recreation Travel with Transportation Planning and Project Delivery provides an overview of current practice at transportation agencies, metropolitan planning organizations, state tourism and parks departments, federal land management agencies, and regional planning agencies. Overall, findings reveal that many state departments of transportation (DOTs) are now actively involved in tourism-related planning issues -- either proactively or in building solutions to infrastructure, access, or environmental issues that impinge on the success of tourism in the region. [More] | |
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328 - State Product Evaluation Programs
8/23/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 328: State Product Evaluation Programs examines the general use of evaluation programs within state departments of transportation (including the use of state specifications, and laboratory and field testing results), the national programs that exist to support the integration of new products and technologies into practice, and the general issues associated with conducting objective evaluations of new products and implementation of approved products. [More] | |
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327 - Cost-Effective Practices for Off-System and Local Interest Bridge
11/19/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 327: Cost-Effective Practices for Off-System and Local Interest Bridges examines off-system bridge design, construction, maintenance, financing, rehabilitation, and replacement. For this report, 'off-system' refers to those bridges typically owned and maintained by local agencies, and by state agencies on rural and other low-volume roads. [More] | |
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325 - Significant Findings from Full-Scale Accelerated Pavement Testing
3/19/2004
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 325: Significant Findings from Full-Scale Accelerated Pavement Testing documents and summarizes the findings from the various experimental activities associated with full-scale accelerated pavement testing programs. [More] | |
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310 - Impact of Red Light Camera Enforcement on Crash Experience
4/10/2003
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 310: Impact of Red Light Camera Enforcement on Crash Experience notes that red light running automated enforcement seemingly can be an effective safety countermeasure; however, the report goes on to indicate that currently there is insufficient empirical evidence based on statistically rigorous experimental design to make a conclusive statement. [More] | |
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306 - Long-Term Pavement Marking Practices
1/29/2003
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 306: Long-Term Pavement Marking Practices documents the current and best practices for managing pavement marking systems, identifies future needs, and addresses driver needs and methods of communicating information to drivers, selection criteria (e.g., reflectivity, pavement service life, wet weather performance), materials (e.g., color, durability, cost), specifications, construction practices, inventory management systems, and more.
Report Parts;
Front Matter
TRB Executive Committee 2002
Preface
Foreward
Acknowledgements
Summary
Chapter One - Introduction
Chapter Two - Process for Making Decisions on Pavement
Chapter Three - Driver Needs, Retroreflectivity Requirements, and Information through Word and Symbol Markings
Chapter Four - Traffic Crashes and Pavement Markings
Chapter Five - Material Selection Criteria
Chapter Six - Specifications and Construction Practices
Chapter Seven - Pavement Marking Materials
Chapter Eight - Inventory Management System for Pavement Markings
Chapter Nine - Performance Evaluation
Chapter Ten - Conclusions
References
Definitions of Pavement-Marking Materials
APPENDIX A - Survey Questionnaire
APPENDIX B - Survey Respondents
APPENDIX C - Annual Pavement Marking Expenditure and Highway Mileage in Year 2000
APPENDIX D - Examples of Pavement Marking Material Selections and Placement Guidelines
APPENDIX E - Example Prescriptive Special Provision for Epoxy Pavement Markings used by the Maryland State Highway Administration
APPENDIX F - Example Performance-Based Special Provision for Waterborne Paint used By The Virginia Department of Transportation
APPENDIX G - Example Warranty Provisions Special Provision For Durable Permanent Pavement Markings used by the Oregon Department of Transportation
APPENDIX H - Example Specificationsfor Glass Beads
APPENDIX I - Example Specifications for Raised Pavement Markers
APPENDIX J - Example Test Method for Quality Control Testing of Pavement Markings used by the Virginia Department of Transportation [More] | |
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305 - Interaction Between Roadways and Wildlife Ecology
11/21/2002
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 305: Interaction Between Roadways and Wildlife Ecology summarizes existing information related to roadway planning, design, construction, operation, and maintenance practices being used successfully and unsuccessfully, nationally and internationally, to accommodate wildlife ecology given the challenging background of rapid growth and diminishing natural resources. [More] | |
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298 - Truck Trip Generation Data
6/26/2002
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 298: Truck Trip Generation Data identifies available data and assesses the current state of the practice in truck trip generation. [More] | |
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297 - Building Effective Relationships Between Central Cities and Regional, State, and Federal Agencies
12/1/2001
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 297: Building Effective Relationships Between Central Cities and Regional, State, and Federal Agencies documents various intergovernmental relationships and practices that have proven successful in furthering the capital, operations, and maintenance needs of urban transportation systems. It addresses questions about how various intergovernmental units work together to address the transportation needs of central cities, what types of relationships have proven successful in achieving this goal, and what practical steps local, regional, state, and federal officials can take to enhance and improve central city transportation systems. [More] | |
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294 - Configuration Management in Transportation Management Systems
7/9/2001
This synthesis report will be of interest to state transportation departments and regional and local agencies, as well as to the consultants that work with them. It identifies how configuration management (CM) is currently being developed and used by transportation management systems. It is intended as a resource document for professionals just beginning to apply CM. This report can be used as a reference tool by agency managers and administrators, as well as other technical personnel, in both the public and private sectors, to locate more in-depth material to support CM programs. The document addresses the fundamental concepts and principles of CM, the need for CM within transportation management systems, and available CM resources (including books, standards, websites, and software tools). Also, it contains information about the status of CM within transportation departments and detailed case studies of the use of CM both outside of and within the transportation field. A glossary is included. An appendix contains an example CM tool. [More] | |
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291 - Evaluation of Pavement Friction Characteristics
12/19/2000
This synthesis report will be of interest to pavement design, construction, management, and research engineers, highway safety officials, and others concerned with pavement friction characteristics. It describes the current state of the practice and discusses the methods used for evaluating wet pavement friction characteristics of new and restored pavements. This synthesis reviews models used for measuring and evaluating friction and texture, causes for friction changes over time, and aggregate and mix design to provide adequate friction. Also presented are construction and surface restoration practices for providing good pavement surface characteristics. In addition, considerations of noise and ride quality are discussed when compromise may be required. [More] | |
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290 - Current Practices for Assessing Economic Development Impacts from Transportation Investments
11/7/2000
This synthesis report will be of interest to DOT administrators, supervisors, and staff, as well as to the consultants working with them in assessing the economic development impacts of existing or proposed transportation investments. Metropolitan Planning Organization regional and local staffs might also find it informative. It is intended to help practicing planners become aware of the range of methods and analysis techniques available, organized by the different categories of agency needs, to address different types of planning, policy, and research needs. This synthesis summarizes the current state of the practice by means of a survey of transportation planning agencies in the United States, Canada, and the United Kingdom. This report provides reviews of the analysis methods used in recent project and program evaluation reports of these agencies, in addition to a bibliography of economic literature and guides. [More] | |
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289 - Corridor Management
10/12/2000
This synthesis report will be of interest to department of transportation administrators and transportation planning, right-of-way, economic development, and environmental planning staffs, as well as to the consultants that work with them. It would also appeal to regional and local government officials and staff, as well as to the private sector. It summarizes information about corridor management policies and programs at the federal, state, and local levels. An effort was made to select a diversity of methods and programs for the broadest treatment of the subject. The synthesis focuses more on roadway corridors than on transit or greenway corridors, but much of the information provided is relevant to any corridor management effort. This report examines state policies and programs, techniques applied, and coordination issues. A series of case studies provides more detailed study. This report of the Transportation Research Board documents successful partnerships. It presents examples of transportation agencies working together, proactively, with local governments and other stakeholders to achieve more cost effective and comprehensive solutions to transportation problems. [More] | |
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288 - Data Sharing and Data Partnerships for Highways
10/24/2000
This synthesis report will be of interest to DOT administrators, supervisors, and staff, as well as to the consultants that work with them. Metropolitan Planning Organization (MPO) regional and local agency staffs might also find it informative. The synthesis was initiated in response to a recommendation made during the Highway Performance Monitoring System (HPMS) Reassessment, which was undertaken by the FHWA in 1997/1998 to expand data sharing and partnering more widely among states, MPOs, and local governments. It documents current arrangements among state DOTs, MPOs, and other local and regional agencies to partner in the collection and share in the use of HPMS data. Key elements examined include institutional arrangements, the use of data and data sharing, cost and resource requirements, technical capabilities/barriers, implementation processes, and data quality and capability, as well as successes, failures, and difficulties. Case studies of successful state and MPO partnerships are included. [More] | |
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286 - Multimodal Aspects of Statewide Transportation Planning
8/15/2000
This synthesis report will be of interest to department of transportation ( DOT) administrators, planning supervisors, managers, and staffs, as well as to planning consultants that work with them. It provides information for practitioners interested in the results of attempts to apply multimodal considerations at the statewide level and identifies key research findings. It covers post-ISTEA (Intermodal Surface Transportation Efficiency Act of 1991) processes and projects and both passenger and freight activities. The report examines the application of three multimodal aspects: alternatives, modal mix, and integration into three statewide planning functions, which include state planning, corridor studies, and financing, budgeting, and programming. The emphasis is on implementation. This report of the Transportation Research Board documents processes and research currently under development, using three approaches: a literature review, results of a survey of state DOTs, and five case studies. It cites the following states with exemplary practices in multimodal/intermodal transportation based on a 1998 report by the policy research project at the University of Texas on Multimodal/ Intermodal Transportation: Florida, Minnesota, Oregon, Pennsylvania, Virginia, Washington, and Wisconsin. [More] | |
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285 - Maintenance of Highway Edgedrains
7/18/2000
This synthesis report will be of interest to pavement design, construction, maintenance, and materials engineers; geologists and hydrologists; highway contractors; and others interested in the maintenance of highway edgedrains. It describes the current state of the practice for the maintenance of highway edgedrain systems (i.e., outlet, headwall, connection, longitudinal/mainline pipe) and procedures to reduce and facilitate the maintenance of edgedrains. Information is provided on the maintenance of edgedrains, its relation to pavement drainage and performance, and the importance and cost benefits of providing good drainage in highways. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search to document North American and European practices. This report of the Transportation Research Board is an extension to the information provided by NCHRP Synthesis of Highway Practice No. 239, " Pavement Subsurface Drainage Systems" (1997). Design, material, and construction details and Techniques, obtained from a survey of North American transportation agencies, are provided to demonstrate effective edgedrain maintenance practices that promote highway drainage. Agency policies and procedures for edgedrain maintenance are also provided. In addition, strategies to reduce edgedrain maintenance costs and methods of increasing maintenance effectiveness are included. [More] | |
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284 - Performance Survey on Open-Graded Friction Course Mixes
3/17/2000
This synthesis will be of interest to pavement construction, maintenance, design, and materials engineers; pavement contractors; and others interested in the use of open-graded friction course (OGFC) mixes. It describes the current state of the practice on the use of OGFC mixes, including information regarding design, materials, construction, maintenance, and rehabilitation strategies. Alternative treatments to traditional OGFC are also identified and discussed. Information was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search to gather additional insight into North American and European practices. This TRB report describes the recent performance of North American OGFC mixes and European porous asphalt by identifying benefits and stress indicators. A new generation of OGFC mixes has evolved over the last 5 years with changes that have been reported to dramatically improve performance. This synthesis describes new materials and design methods being used, as well as the applicability of the new generation of open-graded mixtures to North American use. [More] | |
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283 - Fleet Management and Selection Systems for Highway Maintenance Equipment
4/25/2000
This synthesis report will be of interest to Department of Transportation (DOT) administrators, supervisors, equipment, and Management Information System (MIS)/Information Technology (IT) managers and staff, as well as to the engineering and MIS/IT consultants that work for them. It reviews that state of the practice, updating an earlier effort, NCHRP Synthesis 52: Maintenance and Selection Systems for Highway Maintenance Equipment. The synthesis addresses highway fleet maintenance issues in management, equipment, staffing, and technology. It describes the trend toward more sophisticated and complex MISs and reports on DOT efforts to develop more systematic approaches to measure equipment effectiveness and to incorporate this quantitative technology, successfully, into daily operations. This TRB report profiles specific state agency experience in hiring and retaining mechanics, staffing levels, management system complexity, and technologies. Sample shop work load and productivity reports from the Montana DOT are included. [More] | |
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282 - Project Management Information n Systems
2/24/2000
This synthesis report will be of interest to DOT chief administrative and information officers, information technology staff, and project managers and their supervisors. It describes the current state of the practice for DOT project management information systems, as well as current best practices across other industries. Several case studies and an appendix chapter on change: definition and implementation, role of personnel, processes, and cost are also provided. This TRB report describes the processes used to develop and implement automated project management information systems, the sources of software in use, and the extent of any modifications necessary for commercial projects to fit DOT business needs. It also describes the operating environments for systems in use and the capabilities and limitations of the systems used to track multiple projects and information sources. In addition, information on system capabilities and deficiencies in project communications, report and problem solving, the necessary resources required to implement and maintain each automated system, the length of time each system has been in place, and future plans for long-term enhancement, modifications, or enhancements is included. [More] | |
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281 - Operational Impacts of Median Width on Larger Vehicles
4/4/2000
This synthesis report will be of interest to officials and staff of municipal, regional, and statewide transportation agencies responsible for roadway design and traffic control. It will be of special interest to those concerned with intersections and driveways on divided highways where larger vehicles encounter narrow medians. It will also be of interest to other professionals who interact with these agencies to mitigate such problems. This report presents state-of-the-practice information about current median design policies and practices, describes the traffic operational and safety problems encountered in designing for larger vehicles at divided highway intersections, and identifies alternative improvement techniques that can be used in new construction or reconstruction projects to avoid introducing traffic operational and safety problems. This TRB report focuses on 10 alternative cross sections widely used on arterial highways in urban, suburban, and rural environments. [More] | |
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280 - Seven Keys to Building a Robust Research Program
8/18/2005
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 280: Seven Keys to Building a Robust Research Program identifies attributes necessary to build and maintain a robust research program. [More] | |
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279 - Roadway Incident Diversion Practices
12/19/1999
This synthesis report will be of interest to officials of municipal, regional, and statewide transportation and law enforcement agencies who are responsible for roadway incident diversion practices. It will also be of interest to others who interact with these agencies to achieve a better understanding of the processes, barriers, and technologies associated with alternate route plan development and deployment. This report presents state-of-the-practice information about the development and implementation of roadway incident diversion practices. It documents specific trends in the practice, and in examining individual practices, identifies unique plans, processes, and technologies from which other agencies may find useful applications. This TRB report addresses a broad list of topics associated with roadway incident diversion and profiles successful incident diversion practices, as reported by surveyed agencies. In particular, it focuses concern on alternate route plans for random incidents, those resulting in nonrecurring congestion. [More] | |
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278 - Measuring In Situ Mechanical Properties of Pavement Subgrade Soils
11/8/1999
This synthesis report will be of interest to pavement and geotechnical design and research engineers, geologists and engineering geologists, and related laboratory personnel. It describes the current practice for measuring in situ mechanical properties of pavement subgrade soils. The tests conducted to measure the mechanical properties of soil strength and stiffness are the primary topics, and these are discussed in the context of design procedures, factors affecting mechanical properties, and the variability of measurements. Information for the synthesis was collected by surveying U.S., Canadian, and selected European transportation agencies and by conducting a literature search. This TRB report provides information on existing and emerging technologies for static and dynamic, and destructive and nondestructive testing for measuring in situ mechanical properties of pavement subgrade soils. Correlations between in situ and laboratory tests are presented. The effects of existing layers on the measurement of subgrade properties, and soil spatial and seasonal variability are discussed. Most importantly, the use of soil properties in pavement design and evaluation are explained. New applications or improvements to existing test methods to support the use of mechanistic/stochastic-based pavement design procedures are also explained. [More] | |
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277 - Consultants for DOT Preconstruction Engineering Work
7/26/1999
This synthesis report will be of interest to department of transportation (DOT) preconstruction engineering supervisors and program managers, contract administrators, and project managers. It will also be of interest to engineering consultants who do work for state DOTs. It describes current practice in contracting with consultants for DOT preconstruction engineering work. The synthesis documents the practices in all stages involved with obtaining consulting services, from the initial designation of projects for consultant work to project completion and acceptance procedures. The study also collected the views of selected consultants on DOT practices. Information for the synthesis was collected by surveying U. S. transportation agencies and by conducting a literature search. This report of the Transportation Research Board provides information on the history and trends in outsourcing of preconstruction engineering activities and compares current levels with those found a decade earlier. The steps in the procurement and management of consulting services are provided in detail. These include deciding on when and what to contract out and the selection, negotiation, and consultant management activities that follow. Finally, the appendixes contain numerous samples of collected forms and procedures used by a variety of states to accomplish this work. [More] | |
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276 - Geotechnical Related Development and Implementation of Load and Resistance Factor Design (LRFD) Methods
6/16/1999
This synthesis report will be of interest to geotechnical, structural, and bridge engineers, especially those involved in the development and implementation of the geotechnical aspects of the AASHTO Bridge Code. The synthesis documents a review of geotechnical related LRFD specifications and their development worldwide to compare them with the current AASHTO LRFD Bridge Code. Design procedures for foundations, earth retaining structures, and culverts are summarized and compared with the methods specified by the AASHTO code. This TRB report provides information designed to assist engineers in implementing the geotechnical features of LRFD methods. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search using domestic and international sources. Interviews were also conducted with selected international experts. The limited available experience in the United States and information from international practice are discussed to understand the problems that have arisen in order that solutions may be found. Based on the studies reported here, suggestions for improving the code are identified. [More] | |
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275 - Historic Highway Bridge Preservation Practices
10/18/1999
This synthesis report will be of interest to state highway design engineers and structural engineers, as well as environmental and historic preservation personnel in transportation agencies. It will also be of interest to state historic preservation offices, federal historic preservation agencies, and engineering preservation consultants. It describes the current state of the practice and experience of state and local transportation agencies dealing with the preservation of historic bridges in their jurisdictions. Information for the synthesis was collected by surveying U.S. state and federal transportation agencies and by conducting a literature search. The synthesis is intended to complement NCHRP Synthesis 101, Historic Bridges--Criteria for Decision Making (1983), and draws on that work by reference. This report of the Transportation Research Board provides information on the policies, decision criteria (or models), and administrative practices used to determine which historic bridges to preserve and the specific preservation option to be employed with each. It also emphasizes the experience of highway agencies in administering these policies and practices, describes a number of successful examples, and identifies some unresolved issues. Several case studies are included to highlight the differences between the policies and practices of state transportation agencies and preservation agencies. [More] | |
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274 - Methods to Achieve Rut-Resistant Durable Pavements
5/12/1999
This synthesis report will be of interest to state, local, and federal agency pavement materials, design, and construction engineers, as well as pavement research engineers and scientists. Those with supervisory oversight for pavement programs will also find it of interest. It describes the current practice for methods to achieve rut-resistant durable pavements. The synthesis documents current experience with permanent deformation of asphalt pavements and identifies methods to improve performance. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search using domestic and international sources. This report of the Transportation Research Board describes the extent of the rutting problem on the National Highway System, pavement mixture design issues, and the design of rut-resistant mixtures. In addition, alternate mixture types, including stone matrix asphalt and porous asphalt, are discussed, as well as international approaches to mixture design. Finally, the construction of rut-resistant mixtures, including the role of quality control and quality assurance methods, are discussed. A summary of permanent deformation causes and solutions is included in the appendix. [More] | |
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273 - Project Development Methodologies for Reconstruction of Urban Freeways and Expressways
4/1/1999
This synthesis presents a review of the current practices associated with the techniques and policies employed by state and local transportation agencies to address the many project development issues required for the reconstruction of existing urban and suburban freeways and expressways. This topic is of special interest because there is a need to reconstruct many highway facilities that have been in existence for over 40 years. The need arises both from the deterioration of the infrastructure and from changes in capacity requirements. This synthesis will be of interest to state and local highway design engineers, traffic engineers, finance and contracting specialists, and contracting personnel in these agencies. It will also be of interest to consultants who are engaged in freeway/expressway reconstruction projects. While many of the project development methodologies in practice for reconstruction of urban and suburban freeways and expressways are similar to those used for new construction, there are unique differences that apply primarily to the reconstruction of major urban highway facilities. This report of the Transportation Research Board highlights the similarities and differences in the planning and management of projects as well as in contracting and financing innovations. Methods for effectively managing traffic during the reconstruction process are important to the process, as are traffic control procedures in the work zone. Public participation and public information dissemination related to traffic changes are vitally important to the effective completion of a reconstruction project. Other aspects, such as the design process, including the use of 3-D and 4-D visualization, pavement renewal procedures, environmental impact mitigation and enhancement activities, that are considered in the process are also addressed. [More] | |
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272 - Best Management Practices for Environmental Issues Related to Highway and Street Maintenance
3/24/1999
This synthesis report will be of interest to state, local, and federal agency environmental and maintenance administrators, directors, supervisors, engineers, and scientists. It describes current best management practices (BMPs) for environmental issues related to road and street maintenance. The synthesis documents relevant background and recent information with regard to management practices that can help protect, preserve, or enhance the environment while at the same time allow road maintenance organizations to carry out their fundamental mission of maintenance and repair in a cost-effective manner. Information for the synthesis was collected by surveying U.S. and Canadian state and local transportation agencies and by conducting a literature search using domestic sources. This report of the Transportation Research Board describes BMPs consisting of broad management approaches applicable to the entire maintenance program or to more than one program area. In addition, BMPs for specific maintenance activities or groups of maintenance activities are included. Finally, BMPs concerning specific environmental issues are discussed. [More] | |
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270 - Transportation Management Center Functions
11/21/1998
Transportation management centers (TMCs), or traffic management centers, have become a vital part of the transportation fabric in many urban areas. This synthesis presents information on the current operational and technical practices used by highway, transit, and multimodal TMCs in several urbanized areas. It will be of interest to transportation system administrators, traffic engineers, maintenance engineers, and other officials in state departments of transportation, as well as those responsible for local transportation management and control. In addition, this synthesis will be useful to state and local law enforcement and emergency response personnel. It also provides information to developers and suppliers of hardware and software for traffic control technology and communications systems. This report of the Transportation Research Board describes the various types of TMCs, their functions, and details of design, operations, and staffing. It describes the practice of agencies in the United States and Canada, based on survey responses from 147 TMCs. These agencies are responsible for highways, surface streets, bridges and tunnels, transit, including bus and rail, and several integrated TMCs that include more than one mode. Design criteria describe in detail the physical facility design of TMCs, as well as the software configurations and the interrelationships among TMCs of various types. The required staffing and the personnel roles are highlighted. To the extent that data are available, ranges of costs and benefits for TMCs are included in the report. [More] | |
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269 - Road User and Mitigation Costs in Highway Pavement Projects
3/15/1999
This synthesis report will be of interest to transportation agency planners; design, construction, and maintenance engineers; and administrators, managers, economists, and other decisionmakers involved in programming highway pavement projects. This synthesis describes current practice with regard to road user and mitigation costs in highway pavement projects. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search of both domestic and foreign publications. This report of the Transportation Research Board provides detailed information on the various methods employed by transportation agencies to estimate user costs. The advantages and disadvantages of each are reported. Information on the various components of user costs (i.e., time related, vehicle operating, safety, and environmental costs) is also included. In addition, the study reports on the various mitigation strategies available to agencies to reduce user costs. Information is also provided on how user costs and mitigation strategies have been applied to evaluate different alternatives; and how uncertainties, political considerations, and quality control contribute to the decisionmaking process. [More] | |
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268 - Relationship Between Pavement Surface Texture and Highway Traffic Noise
12/31/1998
Traffic noise is frequently an annoyance for highway neighbors. Pavement/tire noise is a large component of the overall traffic noise level and has been extensively reviewed. This synthesis presents a comprehensive synopsis of pavement/tire noise as it relates to roadways. Detailed information is presented on acoustical definitions and concepts, the theory of tire/pavement noise generation and current mitigation practice, measurement techniques, interior vehicle noise, reported noise emission results for pavement type and texture, effects of pavement wear, surface friction, and maintenance and safety considerations. [More] | |
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267 - Transportation Development Process
1/11/1999
This synthesis presents information on current practices used by transportation agencies to complete the transportation development process (TDP). This process involves linking the planning, project development, environmental, design, construction, operations, and maintenance aspects of the overall transportation program. The purpose of the TDP is to implement a seamless process in which all these elements come together and in which there is continuous public involvement. This report will be of interest to regional and state transportation, planning, and environmental agencies who participate in the TDP and who are involved in both the development and policy aspects of the TDP. This report of the Transportation Research Board describes the history of the TDP, as well as the federal requirements that must be met under both transportation and environmental regulations. This process is made more complex by state and local regulations that must be observed in most jurisdictions. Throughout this process, as carried out by the state transportation agencies and the metropolitan planning organizations, there is continuous public involvement. Other programs, such as the transportation implementation plan, state transportation implementation plan, and environmental programs such as the National Environmental Policy Act, the Clean Air Act Amendments of 1990, and requirements of other environmental laws must be integrated into the TDP. The complexities of this process are described, and some unique approaches to meeting its demands are presented. [More] | |
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266 - Dynamic Impact Factors for Bridges
11/1/1998
This synthesis will be of interest to state department of transportation and consulting bridge, structural, and research engineers. The synthesis describes the current state of the practice for determining dynamic impact factors for bridges. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search using domestic and foreign sources. This report of the Transportation Research Board documents relevant background and recent information with regard to vehicular dynamic load effects on bridges. It provides details on the basic concepts of bridge dynamics, including identification of the main variables affecting bridge dynamic response. In addition, current code provisions for accounting for vehicular dynamic load effects for new bridge design and load evaluation of existing bridges are reported, including a discussion on the background of the provisions. Finally, a discussion of observed field problems associated with vehicular dynamic load effects, as obtained from the survey, are included. [More] | |
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265 - Managing Product Liability to Achieve Highway Innovations
10/1/1998
This synthesis will be of interest to state Department of Transportation (DOT) engineers, legal counsel, researchers, and administrators; transportation product development engineers, equipment manufacturers, and engineering and product manufacturer associations; state, regional, and federal product testing and evaluation centers; and attorneys of law interested in tort liability as it applies to highway innovations. The synthesis describes the current state of the practice for managing product liability to achieve highway innovations. Information for the synthesis was collected by surveying and interviewing state transportation agencies and private transportation related organizations and by conducting a literature search. This report of the Transportation Research Board identifies and discusses specific tort and product liability problems and principles, the specific tort liability experience of public agencies in state DOTs, and the tort liability experience of private organizations involved in introducing new products to the highway market. In addition, details on the litigation risks of highway innovation, the perceptions and perspectives of public agency and private sector personnel, and the state-of-the-art methods to confront litigation risks are presented. Finally, methodological comparisons and a general tort and product liability overview are included in the appendices. [More] | |
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263 - State DOT Management Techniques for Materials and Construction Acceptance
10/1/1998
This synthesis will be of interest to state Department of Transportation (DOT) materials and construction engineers; contract, procedure, and specification specialists; construction personnel managers; researchers; and private consultants. The synthesis describes the current state of the practice of state DOT management techniques for materials and construction acceptance, including approaches to inspection and testing. The associated requirements for maintaining adequate qualified personnel to operate the acceptance and testing programs are considered in the information reported. The information was collected by surveying state DOTs and by conducting a literature search. This report of the Transportation Research Board presents background information on the changing role of specifications, quality assurance processes, warranties, material certifications, and personnel management regarding the state of the practice for state DOT management techniques for materials and construction acceptance. In addition, detailed information is presented on personnel issues. The details of materials test methods and statistical quality control procedures are not included in the report. However, discussion of these technical aspects of materials and construction acceptance are included on the basis of their influence on personnel training requirements, and changes in administrative requirements. [More] | |
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262 - Tolling Practices for Highway Facilities
10/1/1998
This synthesis will be of interest to administrative and financial officials of toll authorities, as well as members of the governing boards of these agencies. It will also be of interest to state departments of transportation and to legislators who are exploring innovative methods for financing major highway facilities. This synthesis also provides useful information for bonding and other financial institutions. It presents information on the current tolling policies and practices employed by highway, bridge, and tunnel tolling authorities throughout the United States. This report of the Transportation Research Board presents a profile of the traditions, pricing practices, and operational aspects of the tolling industry. Based on information derived from survey responses from 41 toll organizations, representing over 90% of annual U.S. toll transactions, the research for the synthesis indicates that the tolling industry employs a wide range of policies and practices, including many innovative approaches, used in response to the need to provide improved highway facilities. Case studies of several selected innovative tolling practices are discussed: variable/congestion pricing; high- occupancy toll, or HOT lanes; public-private partnerships; interagency partnerships; and others such as state infrastructure banks (SIBs), shared resource agreements, and transportation utility fees. Detailed information on the experience of states with privatization of highway facilities is also presented. A unique summary of the future issues to be addressed in the tolling industry as gleaned from the survey concludes the document. [More] | |
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261 - Criteria for Highway Routing of Hazardous Materials
8/1/1998
This synthesis will be of interest to staff of state departments of transportation responsible for highway routing, traffic engineering, traffic operations and signing, and maintenance. It will also be useful to state police, who may also be responsible for routing, and other enforcement personnel, as well as to emergency and fire personnel. The trucking industry will also find the information of value to their operations. Information is presented on the current practices of states for the highway routing of vehicles that transport hazardous materials. The Federal Highway Administration (FHWA) in 1994 issued Guidelines for Applying Criteria to Designate Routes for Transporting Hazardous Materials, which are used by agencies that elect to designate such routes. This report of the Transportation Research Board is based on information obtained from a survey of states concerning the routing of hazardous materials vehicles that asked respondents to rate the importance of 24 factors in the categories of roadway, environment, population, or other criteria in establishing routing policy. The survey also identified the principal agencies responsible for routing, as well as other agencies that typically participate in the routing plan. Enforcement and cost issues are discussed, as is risk assessment. This report presents a unique discussion of the issues as identified by interviews with trucking trade associations and other organizations involved with hazardous materials transport. In addition, technology applicable to more effective monitoring and enforcement is described. The appendices include commodity flow studies and route designation case studies for selected jurisdictions. [More] | |
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260 - Thin-Surfaced Pavements
9/1/1998
This synthesis report will be of interest to pavement design engineers in local, state, and federal transportation agencies. Pavement materials, construction, and maintenance engineers will also find it of interest. In addition, it will be of interest to local technology transfer centers and pavement research engineers. This synthesis describes the state of the practice for thin-surfaced pavement project selection and structural design. It does not establish preferential design criteria (e.g., mix design) nor does it systematically evaluate existing design methods. This report of the Transportation Research Board describes the conditions in which thin-surfaced pavements are considered appropriate, what thin-surfaced pavement types are considered appropriate for given conditions, and the decision criteria used in their selection. Information for the synthesis was collected by surveying state and local transportation agencies and by conducting a literature search, including foreign resources. Case studies and an extensive collection of survey data are presented. [More] | |
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259 - Management of Surface Transportation Systems
6/9/1998
This synthesis will be of interest to officials of municipal, regional, and statewide transportation agencies who are responsible for the management of surface transportation systems in metropolitan areas. It presents information on the processes used by transportation agencies to monitor, evaluate, and implement a variety of solutions to the management of surface transportation systems. This is a complex and dynamic area of application, and the examples presented herein represent a selection of such applications in 1997. The concept of transportation system management is constantly changing and will continue to change, especially with further implementation of intelligent transportation systems. This report of the Transportation Research Board provides an overview of the generalized process that transportation agencies have found to be effective in managing the various aspects of their transportation systems. Specific case examples of effective management strategies are described for several metropolitan areas including Houston, Seattle, metropolitan New York, Los Angeles, San Francisco, and Minneapolis/St. Paul. [More] | |
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258 - Applications of GPS for Surveying and Other Positioning Needs in Departments of Transportation
5/12/1998
This synthesis will be of interest to both administrative and technical personnel in departments of transportation (DOTs), especially in the areas of surveying, mapping, transportation planning, environmental impact assessment, design, construction control, maintenance, operations, vehicle location, and other functions that require accurate location data. This report will be useful for intermodal transportation analyses and for measurement and positioning data for inventories and geographic information systems (GIS). It can also be useful to suppliers and developers of Global Positioning System (GPS) equipment. This report of the Transportation Research Board presents a description of GPS, the major components, basic geodesy principles, how GPS functions, and how it can be applicable to the data and analysis requirements of transportation agencies. The anticipated cost effectiveness of GPS in terms of personnel, equipment, and time as related to the improved accuracies to be derived from GPS applications are described. Current and more advanced applications of GPS by DOTs to different transportation modes are presented. The report also includes a glossary of terms and a listing of GPS information sources. [More] | |
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257 - Maintenance Issues and Alternate Corrosion Protection Methods for Exposed Bridge Steel
5/11/1998
This synthesis will be of interest to state department of transportation (DOT) bridge maintenance engineers, coating specialists, chemists, and researchers. Manufacturers and suppliers of corrosion protection products and systems for exposed structural steel on existing bridges will also find it of interest. This synthesis describes current practice regarding maintenance and protection strategies for exposed structural steel on existing bridges. NCHRP Synthesis 251, Lead-Based Paint Removal for Steel Highway Bridges ( 1997), provides a complementary and more in-depth treatment of maintenance issues involving lead-based paint removal. This report of the Transportation Research Board defines the maintenance management systems and decision making criteria used by transportation agencies for maintaining exposed bridge steel. Material selection criteria, surface preparation and application practices, quality control and quality assurance programs, and funding mechanisms are discussed in detail. The impact of recent and proposed environmental and worker protection regulations on current practice is reported. Information for the synthesis was collected by surveying state transportation agencies and by conducting a literature search. Responses to the survey, Appendix C to this document, are published on the Internet as NCHRP Web Document 11. [More] | |
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256 - Submittal of Bid Proposals in Electronic Format
2/12/1998
This synthesis will be of interest to state Department of Transportation (DOT) contract officers, program managers, and construction engineers. It will also be of interest to computer specialists and construction contractors interfacing with the state DOTs using electronic media processes. It describes the current state of the practice for submittal of bid proposals in electronic format. This report of the Transportation Research Board presents a brief introduction to the history of electronic data interchange (EDI), its relation to electronic bidding, and current applications in the transportation construction industry. The results of a literature review, surveys of state DOTs and highway contractors, and interviews with industry experts and government agencies on the use of electronic bidding for highway projects are presented. Potential benefits and concerns, plus other issues related to the full implementation of electronic bidding in DOTs, are also presented. In addition, reported common plans for near future implementation of EDI technology to electronic bidding system processes for transportation construction projects are included. [More] | |
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255 - Ground Penetrating Radar for Evaluating Subsurface Conditions for Transportation Facilities
3/11/1998
This synthesis will be of interest to state Department of Transportation (DOT) geotechnical, bridge, and pavement engineers, engineering geologists, consultants involved with ground penetrating radar (GPR) investigations for state DOTs, and researchers. It describes the current state of the practice of using GPR for evaluating subsurface conditions for transportation facilities. This was accomplished by conducting a literature search and review and an extensive survey of U.S. and Canadian transportation agencies and practitioners, as well as limited international information collection. GPR is a noninvasive nondestructive tool used in transportation applications such as evaluation and characterization of pavement systems, soils, and environmental problems. This report of the Transportation Research Board presents information on the principles, equipment, logistics, applications, and limitations of GPR pertaining to transportation applications. Selected case studies for which ground truth information is available are presented. In addition, an extensive bibliography and glossary are provided as well as appending information about GPR manufacturers from their literature. [More] | |
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254 - Service Life of Drainage Pipe
4/16/1998
This synthesis will be of interest to state department of transportation (DOT) highway and roadway design and materials engineers, including specifications and standards, geotechnical, chemical, pavement, construction, and maintenance specialists; engineering geologists and geologists; product manufacturers and suppliers; and researchers. The synthesis describes the current state of the practice regarding state transportation agency standards and strategies that determine and define the service life of drainage pipe. Information for the synthesis was collected by surveying state transportation agencies and by conducting a literature search. This report of the Transportation Research Board is an update of NCHRP Synthesis 50: Durability of Drainage Pipe (1978). The synthesis provides detail on the elements influencing material durability considered in the selection of drainage pipe. These elements include the definitions of useful service life and life expectancies of various types of pipe protection systems in differing environments based on such facts as pH, resistivity, abrasion, flow conditions, etc. Protection strategies that influence material durability are also addressed. [More] | |
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253 - Dynamic Effects of Pile Installations on Adjacent Structures
1/8/1998
This synthesis will be of interest to state department of transportation geotechnical, bridge, and structural engineers, engineering geologists, vibration monitoring consultants, contractors involved with pile driving, and researchers. It describes the current state of the practice for preventing and assessing damage to structures adjacent to pile driving installations. This was accomplished by conducting a literature search and review and an extensive survey of U. S. and Canadian transportation agencies and practitioners, as well as limited international information collection. This report of the Transportation Research Board presents information on the theory of ground motion and vibrations due to pile installations, vibration mitigation measures, and the consequences of groundborne vibrations. Additional detailed information on instrumentation used for vibration measurement and the management of vibrations is also included. The appendices include a bibliography, a primer on pile support mechanisms related to pile driving vibrations, several examples of existing agency vibration specifications and contract wording, and an example vibration specification from the literature. [More] | |
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252 - Response of Small Urbanized Area MPOs to ISTEA
2/19/1998
This synthesis will be of interest to officials and staff of metropolitan planning organizations (MPOs) representing regional communities of less than 200,000 population. It will also be of interest to state and local highway and transit agencies, administrators, and elected officials. Other officials, such as state legislators and officials in environmental agencies who interact with the MPOs will also have an interest in this synthesis. It presents information on changes that MPOs in smaller urbanized areas have made in response to the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). The adjustments in policy and practice in developing transportation plans and programs for the agency and the new requirements necessitated by ISTEA are described. With the advent of ISTEA, many of these small MPOs initiated changes in their role within the region and in the transportation planning process applied to carry out this role. Based on a limited sample of small MPOs, the types of changes in policy, procedure, staffing, intergovernmental relations, resource allocation, and training are discussed in this report of the Transportation Research Board. The issues associated with the changes are also highlighted. The techniques (models) that have been applied are described. [More] | |
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251 - Lead-Based Paint Removal for Steel Highway Bridges
12/31/1997
This synthesis describes the current state of the practice for the removal of lead-based paint from existing highway steel bridges. It will be of interest to state department of transportation bridge maintenance and construction engineers; regulators, consultants, and contractors involved with the removal of lead paint from bridges and structures; and structural coatings specialists, chemists, and researchers. Technologies developed over the past several years to remove paint and contain debris, and to protect workers and the environment are described. Detailed information on regulations, agency specifications, lead exposures during coatings removal, and containment practices is also presented. [More] | |
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250 - Highway-Rail Grade Crossing Surfaces
4/3/1998
This synthesis will be of interest to state and local highway personnel who are responsible for the design, construction, and maintenance of road surfaces and to railroad personnel with similar responsibilities associated with highway-rail grade crossings. It will also be of interest to manufacturers and suppliers of pavement and track materials for crossings. It presents information on the current practices related to highway-rail grade crossing surfaces, including the design and selection of crossing surface materials. This report of the Transportation Research Board describes the various types of highway- rail crossing surfaces, and the issues related to design, operation, and maintenance. Design elements include intersection geometry; drainage; special users, such as bicyclists; and descriptions of failures and their causes. Information is presented on crossing material selection factors, including life-cycle costs and on state practices in selection. Funding issues are also discussed. [More] | |
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249 - Methods for Increasing Live Load Capacity of Existing Highway Bridges
12/24/1997
This synthesis will be of interest to state department of transportation bridge design and structural engineers, bridge consultants, and others involved in applied and research methods for increasing the live load capacity of existing highway bridges. The synthesis describes the current state of the practice for the various methods used to increase the live load capacity of existing highway bridges. This is done predominantly for bridges in the short- to medium-span range. Information on the more common bridge material types is presented. There is an emphasis on superstructure rather than substructure strengthening. [More] | |
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248 - Evaluating and Measuring the Effectiveness of Training
11/4/1997
This synthesis will be of interest to transportation agency administrators, especially human resources development managers and training personnel, as well as to the client staff and functional area managers who are responsible for maintaining and improving the level of productivity and quality control within the agency. It will also be of interest to consultants and other organizations that develop training programs for transportation agencies. It presents basic information on the subject of training evaluation and describes examples of practice in several transportation agencies. The overall process for analyzing needs for training, the current evaluation models or processes, and techniques for measuring the results of training are presented. This report of the Transportation Research Board presents discussions of several models and techniques used both within the transportation agencies and in other business settings for evaluating and measuring the effectiveness of training to both the individual and the agency affected. It describes the process of multilevel evaluation measures that begins with a needs analysis to determine desired outcomes of the training. This becomes more important as the training practice has evolved from the typical lecture style to more interactive participation. [More] | |
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247 - Stabilization of Existing Subgrades to Improve Constructibility During Interstate Pavement Reconstruction
10/21/1997
This synthesis will be of interest to state department of transportation (DOT) construction, geotechnical, materials, and pavement system design engineers, engineering geologists, and research engineers, and others concerned with the constructibility of new pavements over existing subgrades. The synthesis describes current practice for the stabilization of existing subgrades to improve constructibility during interstate pavement reconstruction. It presents information regarding the methods available to evaluate and improve subgrade conditions for the purpose of meeting the constructibility requirements of a reconstruction project. This report of the Transportation Research Board presents data obtained from a review of the literature and a survey of the state DOTs. The synthesis reports on: subgrade evaluation methods including sampling, laboratory, and in-situ test methods, as well as assessment of existing drainage systems; constructibility factors such as existing and proposed pavement types, available equipment, and cost effectiveness of various subgrade stabilization techniques; methods of subgrade improvement including mechanical and chemical stabilization, use of recycled and waste materials, the use of geosynthetics in reinforcement and drainage applications; and construction methods with an emphasis on innovative approaches such as novel sequencing of construction traffic, use of lightweight equipment, and robotics. In addition, several case histories describing applicable pavement reconstruction projects are presented. Finally, suggestions to possibly improve the practice and the identification of research needs are also presented. [More] | |
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246 - Outsourcing of State Highway Facilities and Services
10/31/1997
This synthesis presents information on the current outsourcing practices of state departments of transportation with regard to the transfer or placement of work that might previously have been done by state staff, to contractors or consultants. It will be of interest to transportation agency administrators, financial managers, functional area managers, and others who are concerned with the productivity and financial management of state transportation agencies. It will also be of interest to contractors and consultants, as well as to other state agency administrators and legislators. This report of the Transportation Research Board discusses the current outsourcing practices used by state transportation departments in several functional areas: professional design services, right-of-way acquisition, construction, operations and maintenance, and training and other human resources activities. The policies and decision-making practices related to outsourcing, including the methods for determining feasibility and the impediments to outsourcing are discussed. The synthesis also presents evaluative information on the cost- effectiveness of outsourcing, as well as the benefits that are derived, and the problems that have been identified by the agencies. The issues and practices related to public-private partnerships are also discussed. [More] | |
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245 - Traffic Signal Control Systems Maintenance Management Practices
1/1/1997
This synthesis will be of interest to traffic control systems managers and designers, maintenance managers and staff, communications managers and staff, and others who are responsible for the effective functioning of traffic signal control systems at the state, district, or local level. It will also be of interest to consultants and suppliers of traffic signal systems. It presents information on the current practices of state and local transportation agencies with regard to the maintenance management practices for traffic signal control systems. A previous NCHRP Synthesis, No. 114 (1984), examined the state of the practice with regard to traffic signal maintenance management. This synthesis reexamines current traffic signal control maintenance practices in light of the extensive use of solid state equipment, PCs, integrated systems and other advanced technologies, such as ITS ( intelligent transportation systems). This report of the Transportation Research Board discusses the current technologies and the maintenance concerns related to both hardware and software systems. It also presents information on traffic signal systems maintenance organizations and staff, maintenance programming and scheduling, ancillary equipment and repair facilities, cost of maintenance and funding sources, and management strategies. [More] | |
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244 - Guardrail and Median Barrier Crashworthiness
9/25/1997
This synthesis will be of interest to state department of transportation (DOT) roadway design, traffic, structural, maintenance, and research engineers and others concerned with highway safety issues. This synthesis describes the current state of the practice for the use of guardrails and median barriers and their crashworthiness. It includes information about the crashworthiness and typical applications of the most common, permanently installed, nonproprietary guardrail and median barrier systems used in the United States today. A significant amount of detail is included in the text to aid the design, selection, and locating processes for safe and effective guardrails and median barriers. The report presents data obtained from a review of the literature and a survey of state DOTs. The synthesis presents a description of the typical longitudinal barriers in use today, including drawings, the extent of their use, and the most recent testing on each guardrail and barrier system, with particular emphasis on NCHRP Report 230 and 350 requirements. In addition, it discusses the maintenance issues, cost constraints, and common problems with each type of barrier. The synthesis only discusses the crashworthiness of guardrails and median barriers; their transitions and terminals are not discussed. [More] | |
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243 - Methods for Capital Programming and Projection Selection
9/24/1997
This synthesis will be of interest to transportation department administrators, financial managers, program area managers, and others who are concerned with the financing, budgeting, and funding aspects of managing the transportation infrastructure. It will also be of interest to others outside of the state department of transportation (DOT), including state legislators, metropolitan planning organizations ( MPOs), local government officials, and environmental agencies who interact with the DOTs in programming and project development. The synthesis presents information on changes in the capital programming process instituted by DOTs in response to the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and to other factors that affect both policy and practice in developing and managing their capital program. This report of the Transportation Research Board describes key influences on programming, including federal, state, and local regulations, and the changes that have resulted. It also discusses programming and project selection methods used by the states, such as the criteria for setting priorities, use of management systems, tradeoff analyses, and public involvement. The key aspects of revenue forecasting and cash management as they relate to programming issues are also highlighted. [More] | |
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242 - Trenchless Installation of Conduits Beneath Roadways
9/25/1997
This synthesis will be of interest to geologists; geotechnical, construction, and maintenance engineers; other state department of transportation (DOT) personnel involved with the planning, design, and permit issuance for conduits beneath roadways; local transportation agencies; utility contractors and consultants; and trenchless construction equipment manufacturers. It describes the current state of the practice for the use of trenchless technology for installing conduits beneath roadways. Trenchless construction is a process of installing, rehabilitating, or replacing underground utility systems without open-cut excavation. The synthesis is focused on trenchless technology for new installations. This report of the Transportation Research Board describes the trenchless installation technologies ( methods, materials, and equipment) currently employed by state DOTs and other agencies to install conduits beneath roadways. The synthesis presents data obtained from a review of the literature and a survey of transportation agencies. For each technology identified, information is provided to describe the range of applications, basis for technique selection, site specific design factors to be considered, relative costs, common environmental issues, and example specifications. In addition, information on emerging technologies and research needs is presented. [More] | |
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241 - Truck Operating Characteristics
11/11/1997
This synthesis will be of interest to engineers and administrators responsible for the design, construction, and maintenance of highways and bridges, as well as to engineering design consultants. It will also provide useful information to the trucking industry, especially to designers, as they consider the highway interface with regard to the design and operation of heavy trucks. It provides information on the influence of the design and operating characteristics of heavy trucks on highway design, maintenance, and operational performance. Designers of heavy trucks and of the highway infrastructure that is needed to support them, are faced with changing requirements for both systems to operate effectively and safely. Because truck designs tend to evolve more rapidly than highways can be rebuilt or redesigned, inefficiencies can result. This report of the Transportation Research Board describes heavy truck design factors and operating characteristics and their influence on highway planning, design, and performance. The key truck operating characteristics, such as weights and sizes, mechanical properties, turning requirements, accelerating and braking, crash avoidance, pavement and bridge loadings, and the effects on traffic flow are discussed. To more clearly illustrate the subject, matrices of truck and roadway characteristics that are associated with each of these elements are presented. [More] | |
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240 - Toll Plaza Design
8/11/1997
This synthesis presents information on the design of toll plazas at highway, bridge, tunnel, and other transportation facilities. It will be of interest to toll facility managers and other officials, as well as to consultants concerned with the design, operation, and maintenance of toll facilities. It can also be useful to financial personnel, traffic engineers, planners, and security and enforcement personnel. In addition, it provides information to those concerned with environmental issues such as drainage, runoff, lighting, noise, and air quality. The report focuses on the design factors affecting toll plazas, including traffic, toll collection methods, location and configuration of toll plazas, as well as congestion management, operation and maintenance of the facility, and environmental issues. The synthesis includes discussions of existing standards and practices related to toll facility design, including plaza and roadway geometrics, lane configuration, electronic toll collection, capacity, access, communication, safety and security, signing, pavement markings, and new technology. [More] | |
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239 - Pavement Subsurface Drainage Systems
6/20/1997
This synthesis will be of interest to geologists; hydrologists; geotechnical, pavement, construction, and maintenance engineers; and researchers. State department of transportation (DOT) program managers and administrators will also find it of interest. The synthesis describes the current state of the practice for the design, construction, and maintenance of pavement subsurface drainage systems. It provides information on the positive effects of good subsurface drainage and the negative effects of poor subsurface drainage on pavement surfaces. This report of the Transportation Research Board presents data obtained from a review of the literature and a survey of the state DOTs. It is a supplemental update to NCHRP Synthesis of Highway Practice 96, Pavement Subsurface Drainage Systems (1982). The synthesis provides a supplement to design issues not found in Synthesis 96, but faced by current designers, e.g., type and quality of aggregate, compaction requirements for open-graded aggregates, asphalt and cement binders, and use of geosynthetics. In addition, it describes the effects of design, construction, and maintenance decisions on the performance of pavement subsurface drainage systems. [More] | |
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238 - Performance Measurement in State Departments of Transportation
4/18/1997
This synthesis will be of interest to state transportation agency administrators, division and functional area managers, program managers, financial and human resources personnel, and others, including state legislators, who are concerned with implementing innovative programs in state departments of transportation (DOTs). It presents information on the degree to which state DOTs have developed and implemented performance measures in all transport modes for which they are responsible. With the advent of the Intermodal Surface Transportation Efficiency Act (ISTEA), as well as pressure from state governments for greater accountability of state funds, DOTs are increasingly endeavoring to develop performance measures to improve their productivity, and to respond to outside demands from state government and the public. This report of the Transportation Research Board describes how performance measures have evolved in state DOTs, the types of initiatives that have been developed, and the effectiveness of such measures in assessing performance and improving productivity, as perceived by the DOTs. [More] | |
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237 - Changeable Message Signs
3/17/1997
This synthesis will be of interest to traffic engineers in federal, state, provincial, and local transportation agencies who are responsible for the design and operation of safe and efficient highway systems. It will also be useful to consulting traffic engineers, sign manufacturers, and vendors in the private sector who assist governmental clients in the application of changeable message sign ( CMS) and other intelligent transportation systems (ITS) technology. It is an update of NCHRP Synthesis No. 61 (1979). It describes the various types of permanently mounted CMSs in use in the United States and Canada. This technology, also referred to as variable message signs or motorist information displays, is in widespread use in North America. This report of the Transportation Research Board provides information on the various CMS types in use, their typical characteristics, including the technology types, the character (letters and numbers) types and size, and conspicuity. The synthesis presents a discussion on the types of messages used when there are no incidents. Other aspects, such as procurement, maintainability, and warranties are also discussed. [More] | |
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236 - Methods for Household Travel Surveys
1/23/1997
This synthesis will be of interest to planning, administrative, and traffic officials in state transportation agencies and in metropolitan planning organizations (MPOs); to consultants concerned with the design and conduct of surveys; and to those engaged in developing and applying travel forecasting models. It describes the various facets of planning, designing, conducting, and evaluating household travel surveys. This report of the Transportation Research Board provides information on the manner in which many household surveys are currently carried out and provides comment on the likely changes in the process, in the survey instrument, and in the application of more cost-effective methods of data collection in household travel surveys. This synthesis describes the methods for collection, including survey instrument design, as well as testing and administering the surveys. Information on time and cost requirements is also included, as are descriptions of evaluation and data analysis methods. [More] | |
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235 - Application of Full-Scale Accelerated Pavement Testing
1/29/1997
This synthesis, which describes the state of the practice for full- scale accelerated pavement testing (APT), will be of interest to state department of transportation (DOT) pavement design and materials engineers; DOT research staff, including field and laboratory materials testing personnel; and private industry APT equipment suppliers. State DOT administration and management personnel will have a particular interest in the application of APT results toward more efficient and effective pavement designs. Local transportation agencies may also have an interest in the topic. This synthesis reviews the capabilities and limitations of the major APT facilities available worldwide and describes the role and application of full-scale accelerated pavement testing in the development of pavement technology. This report of the Transportation Research Board (TRB) presents data obtained from a review of the literature and a survey of the state DOTs, Canadian transportation agencies, and international organizations. A brief historical overview of APT, a discussion of the application of APT to research, and the application of APT to practice are included. Profiles of APT facilities throughout the world are included in an appendix. [More] | |
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234 - Settlement of Bridge Approaches (The Bump at the End of the Bridge)
3/27/1997
This synthesis will be of interest to state Departments of Transportation (DOTs) geotechnical, structural, roadway design, construction, and maintenance engineers; DOT research staff; and personnel in local transportation agencies. This synthesis describes the current state of the practice for the design, construction, and maintenance of bridge approaches to reduce, eliminate, or compensate for settlement at the bridge/abutment/embankment interface or the bump at the end of the bridge. It discusses the geotechnical and structural engineering design and procedural factors to reduce the bump at the end of the bridge, and includes numerous illustrations. This report of the Transportation Research Board presents data obtained from a review of the literature and a survey of the state DOTs. It is a supplemental update to Synthesis of Highway Practice 159: Design and Construction of Bridge Approaches (1990). The synthesis identifies and describes techniques that have been used to alleviate the problem of the bump at the end of the bridge including the location and cause of settlement and methods used to reduce settlement. In addition, the types of interaction between various divisions of the DOTs in the design, construction, and maintenance of bridge approaches are addressed. [More] | |
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233 - Land Development Regulations that Promote Access Management
8/6/1996
This synthesis will be of interest to state and local transportation agency personnel responsible for access management, as well as to traffic and highway design engineers, land use planners, zoning administrators, environmental specialists, and policymakers or legislators. It describes the various methods for improving traffic operations by managing the location, design, and operation of driveways, median openings, and street connections from business and residential land uses in urban areas. This report of the Transportation Research Board discusses state and local regulatory practice and policy related to subdivision regulations, lot split requirements, development review, access requirements, zoning, and other administrative and legal considerations. The specific regulatory techniques cited by local governments that are used to support access management are identified and discussed, including setback requirements, driveway spacing and operating characteristics, and land use techniques such as minimizing commercial strip development and promoting mixed-use zoning. The increasingly important role of comprehensive planning and intergovernmental cooperation in access management are highlighted. The role of remedial measures, including special exceptions and waivers, is discussed. [More] | |
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232 - Variability in Highway Pavement Construction
11/26/1996
This synthesis will be of interest to state DOT construction, materials, statistical, specification, and inspection engineers; DOT research staff; pavement construction material suppliers; highway construction contractors; and civil engineering consulting firms, including field and laboratory materials testing personnel. The synthesis describes the state of the practice for defining and measuring variability in highway pavement construction. Data obtained from a review of the literature, a survey of state departments of transportation (DOTs), and discussions with selected state DOT personnel and private materials producers are presented. This report of the Transportation Research Board defines several measures of variability but concentrates on the use of standard deviation as the usual measure of variability. The synthesis updates reported typical variabilities found in materials and construction specifications. Also included are discussions of current research activities as related to variability, how variability can be used in the development of specification limits, the use of incentives and disincentives in specifications, and the need for additional information on the variability of several materials and construction processes. [More] | |
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231 - Managing Contract Research Programs
8/6/1996
This synthesis will be of interest to state department of transportation (DOT) research administrators and mid- to upper-level research managers; DOT research staff and staff from design, construction and maintenance who provide input to the research process; and university and private industry researchers. The synthesis describes the state of the practice for managing contract research programs. Data presented were obtained from a review of the literature, a survey of state DOTs, and interviews of selected state DOT, Federal Highway Administration, Transportation Research Board, and university professionals. This report describes all aspects of the research process, from defining the problem and selecting a program, through contract monitoring, to implementation. Successful practices are identified and case studies, representing programs of various sizes, are presented. [More] | |
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230 - Freight Transportation Planning Practices in the Public Sector
11/1/1996
This synthesis describes the process by which state departments of transportation and Metropolitan Planning Organizations (MPOs) integrate freight planning into the surface transportation planning process. It will be of interest to state and MPO planners, port planners; traffic engineers; and to the trucking, rail, and shipping interests in both the public and private sectors. This report of the Transportation Research Board discusses the requirements for freight planning resulting from the Intermodal Surface Transportation Efficiency Act ( ISTEA) with particular emphasis on the development of an intermodal management system (IMS). In addition, that act narrowed the application of the congestion management system (CMS), which is also discussed in the synthesis. Since enactment of that legislation, another act, the National Highway System Designation Act of 1995 was passed and makes the IMS optional rather than mandatory. This has not changed the philosophy or the intent of these planning applications, but it has changed the implementation aspects. Many agencies, however, are continuing with the IMS and CMS planning process. This report describes the methods used by selected agencies for forecasting freight flows, data collection practices, and the techniques for integrating freight planning into the established surface transportation planning processes at the state and regional levels. [More] | |
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229 - Applications of 3-D and 4-D Visualization Technology in Transportation
12/3/1996
This synthesis describes the application of computer graphics technology to transportation practice. It will be of interest to transportation planners, facilities design and construction personnel, traffic engineers, and other officials concerned with administration, public information, legal aspects, right-of-way, maintenance, operations, and safety of transportation facilities. This report of the Transportation Research Board describes the use of 3-D (artist's concepts and image composites) and 4-D (animation) visualization applications in transportation agencies; however, since there are presently only limited applications, it is, in fact, a primer, providing information on the required hardware and software, as well as on costs, production time, and issues of complexity. More detailed information is provided on how data bases are assembled, various types of imagery, how the visualization image is generated, rendering and animation programs, printers and other output and postproduction activities. An extensive glossary is also included. [More] | |
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228 - Reduced Visibility Due to Fog on the Highway
11/26/1996
This synthesis will be of interest to traffic and safety engineers; highway and bridge designers; police, fire, and emergency personnel; toll authorities; and other officials concerned with roadway safety operations. It describes the forecasting and detection of fog, as well as countermeasures that are used by state and local transportation agencies to dissipate fog and to warn motorists during reduced visibility conditions. The presence of fog has often resulted in serious collisions due to reduced visibility. This publication of the Transportation Research Board presents a generalized background on the causes of fog, fog forecasting and detection methods, and how fog affects the roadway and the driver. The various countermeasures practiced by transportation agencies that are described herein range from techniques to dissipate fog to a variety of warning systems to alert drivers to adverse conditions. The National Transportation Safety Board (NTSB) has held hearings and made recommendations for fog countermeasures, which are described in this synthesis. [More] | |
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227 - Collecting and Managing Cost Data for Bridge Management Systems
7/23/1996
This synthesis will be of interest to state department of transportation (DOT) administrators and mid- to upper-level managers; researchers; cost estimators; bridge and general management system engineers; and bridge design, construction, inspection and maintenance engineers; as well as to private industry professionals involved in developing bridge management system (BMS) software and collecting and analyzing BMS cost data. The state of the practice for collecting and managing cost data for BMS is described based on data obtained from a review of the literature and a survey of the state DOTs. This report describes BMS cost data for work done by contract and in-house forces for state and local governments. It includes project-level cost estimation as well as the collection and management of data for network- level cost models. The various cost estimate methods for replacement; maintenance, repair and rehabilitation; and emergency work are analyzed as are the special requirements of user costs and other special economic data. [More] | |
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226 - Remediation of Petroleum-Contaminated Soils
6/10/1996
This synthesis will be of interest to state transportation personnel involved with project planning and location (administrative and regulatory personnel), design staff (general civil, geotechnical, and environmental engineers), and project managers (construction and maintenance engineers and staff). It will also be of interest to federal and state environmental agencies and to environmental consultants and contractors as well as to trainers in the field of petroleum-contaminated soil remediation. This synthesis describes the remedial technologies that may be available to transportation agencies faced with the regulatory responsibility to clean or remediate petroleum-contaminated soils in the vadose zone (unsaturated soils above the groundwater table) at a particular site as well as the state of the practice within the agencies. This report of the Transportation Research Board describes the applicability and cost-effectiveness of alternate technologies to remediate petroleum-contaminated soil. Practices currently being used by state transportation agencies to remediate petroleum-contaminated soils, both on site and off site are also described. This summary of transportation agency practice complements the limited telephone survey of soil remediation techniques that was performed in preparing NCHRP Report 351, Hazardous Wastes in Highway Rights-of-Way. [More] | |
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225 - Left-Turn Treatments at Intersections
4/25/1996
This synthesis will be of interest to traffic engineers in both the public and private sectors, as well as to design engineers, safety and law enforcement officials, traffic signal technicians, and others concerned with the accommodation of nonmotorized transportation ( pedestrians and bicycles) on the roadway. The synthesis describes the traffic conditions, signalization, signing, and geometric design issues associated with accommodating left-turning vehicles at intersections. This report of the Transportation Research Board discusses the basic concerns related to left-turn movements and the guidelines and requirements for handling these movements in the traffic stream. It also addresses the design criteria for left-turn treatments and the performance measures frequently applied to determine their effectiveness. The synthesis discusses the specific requirements for signing and pavement markings, and the various elements of traffic signal requirements, signal design and installation, phasing optimization, and lane-use controls. There is also a description of special applications such as U-turn control, pedestrian requirements, bicycles, and light rail transit interface. [More] | |
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224 - Longitudinal Occupancy of Controlled Access Right-of-Way by Utilities
4/2/1996
This synthesis will be of interest to highway administrators, design engineers, maintenance engineers and maintenance staff, traffic engineers, and safety officials. It will also provide useful information to the utilities and telecommunications industries. Information is presented on the state transportation agencies' policies, practices, and experience associated with occupancy of the rights-of-way on controlled (or limited) access highways. This report of the Transportation Research Board presents a brief history of accommodation of utilities in the right-of-way, including the policies developed over time by the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA) and describes why there are issues associated with joint use of the highway right-of-way. A 1993/1994 survey of the state transportation agencies taken for this synthesis yielded 100% return, indicating the high interest in the subject. Issues included in the survey were policies and experiences regarding user and worker safety; controls placed on utilities; exceptions to right-of-way policies; and operational, legal, and equity issues. [More] | |
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223 - Cost-Effective Preventive Pavement Maintenance (Photocopy Edition)
3/8/1996
This synthesis will be of interest to highway agency executive management including administrative, budget, and finance personnel; pavement design, construction, and maintenance engineers; and maintenance operations personnel, including supervisors and maintenance crew leaders. This synthesis describes the state of the practice with respect to setting a coherent strategy of cost-effective preventive maintenance for extending pavement life. This report of the Transportation Research Board describes the practices of state, local, and provincial transportation agencies that are attempting to minimize the life-cycle costs of pavements and are identifying, during the design of the pavement rehabilitation, reconstruction, or construction projects, the future preventive maintenance treatments and the timing and funding for those treatments. It includes a review of domestic literature and a survey of current practices in North America. The appendices include a primer on pavement design and construction, the benefits of preventive maintenance of pavements, a summary of the questionnaire data collected, a simulation of pavement management strategies, and an example process to demonstrate the cost- effectiveness of preventive maintenance. [More] | |
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222 - Pavement Management Methodologies to Select Projects and Recommend Preservation Treatments
2/2/1996
This synthesis will be of interest to highway administrators; pavement management system (PMS), maintenance, and computer engineers; and technologists involved with data collection and computer programming for the purposes of a PMS. This synthesis describes the state of the practice with respect to pavement management methodologies to select projects and recommend preservation treatments. This report of the Transportation Research Board also describes the predominant pavement management methodologies being used by U.S. state and Canadian provincial transportation agencies; provides a general description of each methodology; and summarizes the requirements, benefits, hindrances, and constraints associated with each. It includes a review of domestic literature and a survey of current practices in North America. In addition, case studies are included to illustrate the use of these methodologies within transportation agencies. Operational and soon-to-be implemented technologies are also discussed, and an extensive bibliography is provided for further reference. [More] | |
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221 - Assessing the Effects of Highway-Widening Improvements on Urban and Suburban Areas
2/28/1996
This synthesis will be of interest to highway environmental specialists (particularly those concerned with assessing social and economic impacts), design engineers, planners, utility managers, and others responsible for the planning, design, and implementation of highway-widening improvements. Information is presented on the reasons for highway-widening projects, the nature of the projects, and the methods and practices for application of analytical techniques used to measure the potential or actual impacts of the projects on people and the physical environment. Mitigation measures are also discussed. This report of the Transportation Research Board describes the most recent widening projects as reported by states or other transportation agencies, as well as the most frequently encountered issues in highway widening. Selected examples of widening projects are included, as is some recognition of the need for additional information and research in the areas of social and economic impact measurement. [More] | |
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220 - Waterproofing Membranes for Concrete Bridge Decks
2/2/1996
This synthesis will be of interest to research, specifications, materials, design, and construction engineers; contract and specification administrators; agency project managers and staff; and concrete bridge deck construction contractors. This synthesis describes the state of the practice with respect to the development and present status of waterproofing membranes for concrete bridge decks. This report of the Transportation Research Board describes the use of waterproofing systems applied to new bridge decks and the rehabilitation of deteriorated concrete bridge decks. In addition, this synthesis describes current practice with regard to methods for assessing the effectiveness of membranes, criteria for use, installation practices, and factors that affect the performance of waterproofing systems in new construction and rehabilitation. Suggestions for future research are also included. [More] | |
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219 - Photographic Enforcement of Traffic Laws
12/22/1995
This synthesis will be of interest to state and local highway agency administrative and executive officers, enforcement agency personnel, attorneys, traffic engineers, and others concerned with managing and enforcing traffic laws at all levels of government. It will also be of interest to manufacturers and marketers of automated speed enforcement ( ASE) technology. The synthesis describes the requirements, applications, effectiveness, and issues related to the use of ASE technology. This report of the Transportation Research Board describes the various types of ASE technology as applied in several localities, including descriptions of operational requirements and performance characteristics of these technologies. The synthesis also discusses how citations are processed, and examines the legal and acceptability issues related to ASE technology and public views on these actions. The various technologies on the market at the time of preparation of this synthesis are also described. It should be noted that, as with any application of public surveillance technology, officials are well advised to exercise proper cautions when employing such enforcement procedures. [More] | |
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218 - Mitigation of Nighttime Construction Noise, Vibrations, and Other Nuisances
8/2/1999
This synthesis report describes current practice in mitigating nighttime construction nuisances such as noise, vibration, light, and dust. Roadway construction work is increasingly done at night to mediate traffic congestion; however, this trend also increases the potential for disturbing adjacent property owners. This report will be of interest to department of transportation (DOT) construction, design, and project engineers, and to those responsible for community relations. This report of the Transportation Research Board stresses the importance of informing project neighbors and establishing cooperative relations with the community as a first measure of successful mitigation. Examples show how project design can address construction nuisances by locating and sequencing construction operations to minimize their impact. Current practices used in source control, path control, and receptor control are described and documented in examples from the Boston Central Artery/Tunnel project and projects in Arizona and Salt Lake City, Utah. Appended materials provide sample specifications for mitigation of noise and dust control. [More] | |
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217 - Consideration of the 15 Factors in the Metropolitan Planning Process
7/24/1995
This synthesis will be of immediate interest to land use and transportation planning officials, with special interest to state, regional, and local planners and administrators who must respond to the requirements of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). The process for incorporating the 15 factors into the comprehensive land use and transportation plans by metropolitan planning organizations (MPOs) and the 23 factors into statewide plans by state planning agencies is described in this synthesis. Because the planning process is in a constant state of flux and many deadlines have been shifted, this report of the Transportation Research Board represents practice during mid 1994, and includes several case study examples of MPO approaches to addressing the 15 factors in their region. This synthesis provides information on how some agencies have succeeded in incorporating the 15 factors in the early stages of ISTEA implementation; however, it is not intended to be a guideline. Specific issues and concerns, both now and in the future, are highlighted, as are the elements that need to be considered throughout the complex process of responding to ISTEA and the 1990 Clean Air Act Amendments requirements. [More] | |
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216 - Implementation of Technology From Abroad
4/21/1995
This synthesis report will be of interest to pavement design, materials and testing, traffic, and research engineers and transportation planners. It will also be of interest to chief administrative officers and chief engineers of transportation agencies. This report describes the current implementation by transportation agencies in the United States of technologies that were developed abroad. This report presents several case studies, including mechanically stabilized embankment technology, asphalt pavement materials and testing equipment, a tunneling method, moveable barriers, an accelerated loading facility, and a bicycle and pedestrian planning process. This report of the Transportation Research Board provides information on the formal and informal processes that have been made by U.S. agencies to employ technologies and methodologies from abroad, including descriptions of both successes and failures and the reasons for implementation of the technology. The technologies that are described originated in France, Germany, Austria, Finland, and Australia. [More] | |
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215 - Determination of Contract Time for Highway Construction Projects
6/30/1995
This synthesis will be of interest to highway administrators; design, construction, and specification engineers; project schedulers; and highway construction contractors. The synthesis describes the state of the practice with respect to procedures used throughout the United States and other countries to determine highway construction contract time, with emphasis on new methods in use. Transportation agencies must set reasonable times for completion of construction projects. Factors to be considered in determining contract time include materials, equipment, labor, cost, and constraints such as weather, traffic conditions, utilities location, and user convenience. This report of the Transportation Research Board covers the still pertinent procedures from NCHRP Synthesis 79: Contract Time Determination (e. g., critical path methods, linear scheduling, bar charts) as well as new methods in use (e.g., A + B methods, lane rental, flexible time-to- start). In addition to information on various methods to determine contract time, information on issues related to implementing procedures for contract time determination, from both agency and contractor perspective, is included. [More] | |
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214 - Resolution of Disputes to Avoid Construction Claims
8/4/1995
This synthesis report will be of interest to transportation agency administrators, including contract administrators; construction, design, claims, and scheduling engineers; project staff and managers; attorneys; and construction contractors. This synthesis describes the state of the practice with respect to procedures used throughout the United States to resolve disputes to avoid construction claims. Fair and timely resolution of contract disputes may help lessen highway construction project administrative costs, benefitting the public, the agency, and the contractor. This report of the Transportation Research Board examines the underlying reasons for contract disputes and identifies methods for dispute avoidance and resolution. It complements the information in NCHRP Synthesis of Highway Practice 105: Construction Contract Claims: Causes and Methods of Settlement, which focused on the causes of disputes. This synthesis further emphasizes finding ways to settle disputes at their inception, before they become formal claims or lawsuits. [More] | |
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213 - Effective Use of Park-and-Ride Facilities
7/5/1995
TRB's National Highway Cooperative Research Program (NCHRP) Synthesis 213: Effective Use of Park-and-Ride Facilities examines the current status of park-and-ride facilities in the United States. The various aspects of park-and-ride facilities, including conceptual issues, location, design, administration, operation, maintenance, and other supporting elements are addressed in this synthesis. The report also provides information on the current usage of park-and-ride facilities throughout the nation, operating and maintenance practices at selected sites, descriptions of safety and security measures used at various facilities, and the relationship of ridesharing and travel demand management programs to the success of park-and-ride facilities. [More] | |
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212 - Performance-Related Specifications for Highway Construction and Rehabilitation
9/7/1995
This synthesis will be of interest to administrators, including contract and specifications administrators; research, construction, materials, specification, and design engineers; agency project managers and staff; and highway construction contractors. It describes the state of the practice with respect to the development and present status of performance-related specifications (PRS) for highway materials and construction. This report of the Transportation Research Board summarizes the historical events that have prompted U.S. interest in PRS development and describes the underlying concepts. In addition, it describes current practice with regard to PRS implementation and refers to the principal PRS literature with emphasis on performance and cost models. It emphasizes the utility of PRS in providing objective/ rational measures that can be used for special contract conditions, such as incentive or disincentive adjustments. [More] | |
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211 - Design, Construction, and Maintenance of PCC Pavement Joints
5/9/1995
This synthesis report will be of special interest to pavement engineers and pavement construction and maintenance personnel responsible for portland cement concrete (PCC) pavement joints. Still pertinent information from NCHRP Synthesis 19 (1973), as well as new or updated information in the areas of joint design, construction, and maintenance are included. This report of the Transportation Research Board records the state of the practice with respect to the design, construction, and maintenance of PCC pavement joints. In addition, information on joint materials and sealing, the control of water on and in pavements, and the evaluation of pavement joint performance is provided. [More] | |
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210 - Road Pricing for Congestion Management: A Survey of International Practice
3/22/1995
This synthesis will be of interest to transportation agency administrators and managers, state and regional transportation planners, metropolitan planning organizations, policy makers, transportation economists, traffic engineers, and others concerned with reducing traffic congestion in urban areas. The synthesis describes the experience of several foreign countries that have used road pricing, or congestion pricing, as a means to manage congestion. The synthesis contains discussions of the policy, equity, and implementation issues associated with congestion pricing. Several of the schemes described were planned or implemented as methods to increase roadway funding rather than for congestion management, but have had the effect of changing travel patterns. The case examples describe the congestion management schemes in Singapore, Hong Kong, Norway, Sweden, France, the Netherlands, and the United Kingdom. This report of the Transportation Research Board also describes the various congestion pricing schemes implemented or proposed that rely on automated or electronic vehicle use charges. The case examples include ring roads, corridors, restricted areas or zones, and areawide applications. The opportunities and cautions for implementing similar congestion pricing measures in the United States are also discussed. [More] | |
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209 - Sealers for Portland Cement Concrete Highway Facilities
3/7/1995
This synthesis document will be of interest to materials, maintenance, and bridge engineers, and others responsible for protecting and maintaining portland cement concrete (PCC) roadway surfaces. It will be of special interest to materials research and testing officials, as well as to manufacturers who are concerned with developing and evaluating sealers for PCC highway facilities. The information in this Synthesis is limited to surface-applied liquid sealers that are primarily intended to retard the transmission of water and ions below the roadway surface. This report of the Transportation Research Board provides detailed information on generic concrete sealing materials that may be considered a primer on the topic, describing the various classes of sealers, their chemical characteristics, application to specific needs, and practice and performance characteristics. In addition, information is provided on evaluation and testing, application and costs, and the safety and environmental issues of concern with their use. Also included is a glossary of terms, extensive references, and an appendix that includes materials on a procedure for the estimation of service life and a model sealer specification. [More] | |
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208 - Development and Implementation of Traffic Control Plans for Highway Work Zones
3/8/1995
This synthesis report will be of interest to traffic control plan designers and administrators; highway engineers (traffic, safety, project, and resident construction); highway construction contractor personnel; and consultants, inspectors, and technicians involved with the design, implementation, and revision of highway work zone traffic control plans. Information on the state of the practice in traffic control plan (TCP) management methods is presented. The emphasis of the synthesis is on innovative and efficient methods that lead to safe traffic control in work zones. The document emphasizes efficient management of the four stages (predesign planning, design, implementation, and revision) of TCPs for different classes of highways and streets in both rural and urban environments. [More] | |
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207 - Managing Roadway Snow and Ice Control Operations
3/7/1995
This synthesis report will be of interest to transportation agency maintenance engineers, managers, and operators and others involved with roadway snow and ice control including safety engineers, traffic engineers, and law enforcement agency personnel. It presents information on the state of the practice in managing roadway snow and ice control considering both rural and urban locations. The document describes the developments that have occurred during the past 20 years to improve winter maintenance. This report of the Transportation Research Board discusses winter maintenance policies and provides examples for state, city, and county agencies. Included in the discussion of winter maintenance policies are issues such as: levels of service, public relations, liability for services, and experimenting with new policies. Additional information is included on estimating winter maintenance benefits and costs; personnel and management issues; weather information systems; and materials, equipment, and facilities for winter maintenance. [More] | |
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206 - Managing Highway Tort Liability
1/12/1995
This synthesis will be of interest to highway agency administrative and executive officers, risk managers, legal officials, as well as to highway design, traffic, and safety engineers, enforcement agency personnel, claims managers, and others concerned with managing tort liability programs in state transportation agencies. It describes the state of the practice with respect to the manner in which these agencies manage highway tort liability programs. Management of claims associated with highways, streets, and pedestrian facilities is the focus of this synthesis, which describes program elements, costs, staffing, risk avoidance, and management requirements. This report of the Transportation Research Board describes the design and implementation of procedures and techniques to manage tort liability programs. Much of the material in this synthesis is also applicable to managing risks associated with modes other than highways within the state transportation agency. There is also applicability to local highway agencies, toll authorities, and public transit agencies. [More] | |
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205 - Performance and Operational Experience of Crash Cushions
2/8/1995
This synthesis report will be of special interest to maintenance, construction, and traffic engineers and others interested in the use of impact attenuation devices or crash cushions for highway operations. Information is provided on the performance and operational experience of 13 crash cushion devices in current use in the United States and Canada, including physical characteristics, test results, and guidelines for use. Both permanent and temporary devices are included. Crash cushions can provide a cost-effective method for reducing or alleviating motor vehicle related injuries or fatalities, which constitute a major societal cost. This report of the Transportation Research Board presents information on the physical and impact performance characteristics of 13 crash cushions in current use in North America. Information on performance evaluation guidelines, physical characteristics, performance characteristics, selection considerations, and the operational experience of individual designs for crash cushions is provided. The synthesis concludes with possible future trends for crash cushions and appendices containing the crash test requirements of NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features, a crash cushion glossary, and a bibliography. [More] | |
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204 - Portland Cement Concrete Resurfacing
12/13/1994
This synthesis report will be of special interest to pavement designers, materials engineers, and others seeking information on portland cement concrete resurfacings (overlays) placed over both portland and asphalt cement concrete pavements. Information is presented on the various practices in use for the design, material selection, and construction techniques associated with each pavement type. Additional information is provided on resurfacing experience and performance, including an Appendix cataloging more than 700 existing resurfacing projects in North America. Transportation agencies in the United States are continuing to develop pavement management systems which take an objective and structured approach to life-cycle cost analysis requirements for pavement rehabilitation project analysis. This report of the Transportation Research Board also discusses the considerations involved in the selection of technically feasible resurfacing alternatives. Based on the longitudinal experience of 375 resurfacing projects that were cataloged in 1982 and the more than 700 projects identified in 1993, much useful information on the performance characteristics of portland cement concrete resurfacing is presented. [More] | |
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203 - Current Practices in Determining Pavement Condition
12/29/1994
This synthesis will be of interest to pavement designers, maintenance engineers, planners, and others concerned with measuring the condition of existing pavements for the purpose of planning maintenance, rehabilitation, or reconstruction. Information is presented on the various practices in use for the collection, reporting, and application of pavement condition data for their service in Pavement Management Systems (PMS) in the United States and Canada, focusing on four primary measures of pavement condition: distress, roughness, structural capacity, and friction resistance evaluations. Nearly all transportation agencies are using or are in the process of implementing PMS for scheduling rehabilitation and maintenance activities. These systems require data on pavement condition and structural capacity. This report of the Transportation Research Board describes the types of equipment being used by state transportation agencies to obtain these data and how the data are used to affect decision making by transportation managers. [More] | |
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202 - Severity Indices of Roadside Features
10/3/1994
This synthesis will be of interest to highway administrators, safety officials, design engineers, traffic engineers, and analysts who are concerned with improving highway safety. Severity indices, which serve as indicators of the expected injury consequences of a crash, are an integral part of the analysis of proposed roadside safety improvements. Severity indices that have been developed by many states and research agencies are described, as are the issues associated with developing the values, and applying and evaluating the indices. The history of severity indices, the issues associated with estimating accident severity and associated costs, and the range of indices that have been developed are described. This publication of the Transportation Research Board also discusses the relationship of accident severity indices with the American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide and the Federal Highway Administration (FHWA) ROADSIDE computer program. While research since the 1960s has sought to quantify severity indices for a range of object types and impact conditions, there remains a wide variation in the values from which analysts may choose when performing cost effectiveness evaluations. [More] | |
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201 - Multimodal Evaluation in Passenger Transportation
11/23/1994
This synthesis will be of interest to transportation planners, environmental analysts, and government officials at the federal, state, regional, and local levels. It describes the state of the practice with respect to the procedures and methodologies used by planning agencies at all levels to plan and evaluate alternative multimodal passenger transportation and to integrate these plans with related land use and environmental issues. This report of the Transportation Research Board describes the federal studies and guidelines that are available and presents the findings of an extensive survey of state, regional, and local agencies to identify the evaluation methods that are being used in the practice. Selected case studies for five types of modal evaluation are presented: intercity corridor, regional study, regional screening, urban corridor, and regional programming. [More] | |
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200 - Underwater Bridge Maintenance and Repair
9/1/1994
This synthesis on underwater bridge maintenance and repair will be of special interest to bridge maintenance engineers and others involved with repair of bridge elements located below the waterline and in the splash zone. Procedures for correctly assessing the problem and engineering the repair within the constraints of individual situations, including bridge scour considerations, are described. Protection, maintenance, and repair of concrete, masonry, steel, and timber bridge foundation elements are also addressed. This synthesis updates the maintenance and repair portion of NCHRP Synthesis 88: Underwater Inspection and Repair of Bridge Substructures. This report of the Transportation Research Board identifies and describes current practices and innovative repair techniques for problems associated with settlement, scour, and deterioration of underwater bridge elements. The synthesis considers various types of protection, maintenance, and repair work on bridge substructures, both underwater and in the splash zone, and includes techniques, and their effectiveness. Current research in the topic area and critical research needs are also identified. A limited bibliography is also provided. [More] | |
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199 - Recycling and Use of Waste Materials and By-Products in Highway Construction
7/26/1994
This synthesis will be of interest to administrators and policy makers; pavement, material, geotechnical, and environmental engineers; and maintenance and construction professionals involved with highway design and construction issues. Information is provided on the technical, economic, and environmental aspects (including legislative and regulatory considerations) of recycling and using waste materials and by-products in highway construction. The quantities, characteristics, possible uses, current and past research activities, and actual highway construction use of each waste material or by-product is provided. This information, based on a review of nearly 1,000 references and on responses to a 1991 survey (updated in 1993), is classified into four broad categories based on source: agricultural, domestic, industrial, and mineral wastes. A Technical Appendix to this document containing an extensive bibliography, supporting information, and details regarding the use of selected waste materials and by-products is available separately from the Transportation Research Board. [More] | |
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198 - Uses of Recycled Rubber Tires in Highways
1/1/1994
This synthesis on the use of recycled rubber tires in highways will be of interest to administrators and policy-makers; pavement, materials, geotechnical, environmental, and traffic operations engineers; and research engineers involved with highway design and construction issues. Information is provided on the uses of rubber tires in asphalt paving materials as well as other uses, such as on fills and embankments, for erosion control and on railroad grade crossings. Specifically, information is included which identifies the agencies using or implementing applications for recycled rubber tires and defines the design parameters, technical and construction limitations, performance, costs, benefits, environmental limitations, specifications, and availability. This synthesis of information defines the use of recycled rubber tires in highways and is based on a review of nearly 500 references and on information recorded from state highway agency responses to a 1991 survey of practice. Updates are included for as much of the state practice information possible through 1993. The use of scrap tires for highway applications is dynamic with regard to policy and technical issues. Therefore, the reader should keep in mind that the information presented reflects the best available data at a particular time. The synthesis also identifies current research in the topic area, critical research needs, and legislative issues that affect application and use of recycled rubber tires. [More] | |
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197 - Corridor Preservation
10/3/1994
This synthesis will be of interest to transportation agency administrators, planners, attorneys, environmental officials, and engineers in federal, state, and local governments, as well as to citizens interested in corridor preservation. It is especially timely in view of the ISTEA provisions for corridor preservation, although the requirements and conditions are changing. This synthesis describes the state of the practice with respect to the experience and status of corridor preservation for highways in the United States. The report describes the many elements of the corridor preservation process, including project development, advance acquisition, fee-simple acquisitions, and other options, as well as environmental issues. This report of the Transportation Research Board presents detailed information on acquisition techniques such as exactions, subdivision control ordinances, transfer of development rights, purchase options, and access management. Detailed discussions of maps of reservation and legal issues, such as land use law, are also addressed. In addition, innovations in corridor preservation are highlighted and future research is suggested. This synthesis also contains several case examples that illustrate a range of practice. [More] | |
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196 - Highway Maintenance Procedures Dealing with Hazardous Material Incidents
8/31/1994
This synthesis will be of interest to maintenance managers, maintenance engineers, health and safety officials, those responsible for environmental protection, police, and others concerned with responding to hazardous materials incidents on public highways. Information is presented on the educational, training, and equipment needs of maintenance personnel, as well as on the procedures for response, containment, and cleanup of hazardous materials. This report of the Transportation Research Board discusses the procedures that are required by federal or state regulations and identifies the various response systems and responsibilities in effect in the states. It describes cautions and caveats that are generally recommended with regard to the training and involvement of highway maintenance forces. Awareness training is noted as the primary and necessary requirement for maintenance personnel. Recommendations for improvements to educational procedures are also included. [More] | |
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195 - Use of Warranties in Road Construction
1/1/1994
This synthesis on the use of warranties in road construction will be of interest to administrators, engineers, designers, and contractors involved with highway design and construction and the procurement process for these services. Experiences with use of warranties in Europe and the United States are cited and the potential impacts, benefits, and concerns of using warranties in the United States are identified. Actions needed to facilitate the use of warranties for highway projects in the United States are also discussed. The use of warranties in road construction is relatively widespread in the European highway industry compared to practice in the United States, where use has been limited. This report of the Transportation Research Board describes the various methods used in Europe for highway industry warranties and identifies the issues that need to be addressed before construction warranties can be translated to U.S. practice. Recent congressional proposals call for the use of warranties to be allowed on federal-aid highway projects. This has caused varied reactions from the parties involved in the design and construction of highways, resulting in a General Accounting Office study on methods for improving the quality of federal-aid highways, including the use of warranties. Ultimately, the owner will have to decide whether to use warranties in highway construction projects. Some of the potential benefits and concerns of using warranties, plus needed actions for successful implementation are presented in this synthesis, which is considered a snapshot of the issues at the time of publication. [More] | |
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194 - Electronic Toll and Traffic Management (ETTM) Systems
1/1/1993
This synthesis on Electronic Toll and Traffic Management (ETTM) systems will be of interest to officials of toll authorities, traffic engineers, design engineers, law enforcement officials, financial personnel, developers and vendors of electronic vehicle identification and toll collection equipment, and others responsible for the design and operation of toll facilities. The technology, including examples of applications of several current ETTM systems, is described in this synthesis. Because the technology is in the early stages of implementation, there is little experience with the TM (traffic management) aspects of ETTM; however, the potential for traffic management systems is discussed. Various electronic toll collection ( ETC) and automatic vehicle identification (AVI) systems, their characteristics, advantages/disadvantages, payment options, and performance experience are described. The computer requirements and relative costs of various applications are also discussed. This report of the Transportation Research Board presents information on specific system design and operational considerations, as well as on the more sensitive issues of enforcement, privacy, and equity in providing these advanced systems. This technology is changing rapidly, and the synthesis presents a snapshot of the industry at the time of its preparation. [More] | |
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193 - Hot In-Place Recycling of Asphalt Concrete
8/9/1994
This synthesis will be of interest to administrators, pavement designers, highway, material, research, and specification engineers, and others interested in economical methods for reconstructing or rehabilitating asphalt concrete pavements. It describes the processes and equipment used for hot in-place recycling of asphalt concrete and provides information on mix designs, performance, and guidelines for its effective use. A significant amount of the information provided is based on the current practices of state highway agencies. As such, numerous case histories are included in the report. [More] | |
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192 - Accident Data Quality
1/1/1993
This synthesis will be of interest to highway department administrators, accident records personnel, information systems and data processing management personnel, highway traffic and safety engineers, drivers' licensing officials, state and local police, as well as federal agencies, industries, traffic safety associations, and others responsible for the collection, analysis, and use of accident data. Information is provided on national accident data banks in addition to state and local practice associated with accident data collection, analysis, and evaluation. This synthesis describes current practice with respect to the characteristics and importance of accident data quality, including the reporting and data collection procedures, the analysis and quality control measures employed, and the communications systems used. This report of the Transportation Research Board discusses accident records systems, including data sources and users, considers the effects of inadequate data on analyses, and reviews data acquisition and processing programs that have had good results in the states using them. Recommendations for improving operating systems and for additional research are included. [More] | |
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191 - Use of Rumble Strips to Enhance Safety
1/1/1993
This synthesis will be of interest to traffic engineers, highway design engineers, highway maintenance personnel, those responsible for toll plaza design and operation, and others concerned with the operation, safety and design of the roadway environment. Information is presented on the various applications of rumble strips on the traveled way and on highway shoulders. This synthesis describes the state of the practice with respect to placement, operational and safety effects, design, installation, and cost and service life of rumble strips. This report of the Transportation Research Board also discusses the effectiveness of rumble strips in preventing or reducing accidents. It provides information on the potential adverse effects of rumble strips, such as noise, motorist use of opposing lanes to avoid rumble strips, maintenance problems, and concerns of special users such as senior citizens, bikers, and truckers. The need for signing and public information support are also discussed. The synthesis presents several recommendations for future research. [More] | |
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190 - Criteria for Qualifying Contractors for Bidding Purposes
7/26/1994
This synthesis will be of interest to administrators, contracting officers, engineers, and contractors, as well as bonding firms and sureties or others involved with highway construction and the procurement process for these services. Information is provided on the current practices used by state highway agencies to qualify contractors for performing competitively bid contract work. The synthesis covers the evolution of the various practices of qualifying contractors by public agencies and private sureties for public construction, discusses the surety industry perspective, and addresses the areas of overlap between them, as well as the important differences. Specific advantages and disadvantages of prequalification and postqualification practices are highlighted. This report of the Transportation Research Board also describes the bonding process, methods used by public agencies to determine the contractor's bonding capacity, and the extent to which only bonding is required by states. [More] | |
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189 - Pavement Structural Design Practices
1/1/1993
This synthesis will be of interest to pavement, highway, and geotechnical engineers, and others interested in pavement structural design practices. Information is provided on flexible and rigid pavement design, design elements common to flexible and rigid pavement, and flexible and rigid pavement overlay design. Additionally, the synthesis discusses pavement research currently underway and recently completed by researchers of the United States and Canada. The structural design of flexible and rigid pavements has evolved from the application of engineering judgement to include a variety of processes. This report of the Transportation Research Board describes the various methods for structural pavement design in the United States and several Canadian provinces. Only the structural aspects of design are considered, i.e., those intended to provide strength or stiffness to the pavement. The functional aspects of design (such as skid resistance), are not considered. [More] | |
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188 - Management Training and Development Programs
1/1/1994
This synthesis will be of interest to administrators, human resource managers, technical managers, and those who develop training courses for departments of transportation (DOTs). It describes the management philosophies that support the management training and development programs, such as the need for effective leadership, customer service as a primary mission, increased workforce productivity, employee involvement, teamwork for more effective results, and the need for a systems perspective by management. Major issues, including the increasing nonengineering functions within DOTs, the aging and diversity of the workforce, recruitment of entry level professionals, employee retention, and the use of contract services are discussed. This report of the Transportation Research Board examines the types of management and development training courses that are considered important by state departments of transportation, costs of training, types of participants, topics that are covered, needs for transportation-related courses vs. administrative training, and the development of courses within the DOT. Suggestions for future management training objectives are also presented. [More] | |
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187 - Rapid Test Methods for Asphalt Concrete and Portland Cement Concrete
1/1/1993
This synthesis will be of interest to materials and construction engineers, and others interested in the use of rapid test methods for asphalt concrete and portland cement concrete. Information is provided on the various test methods in use for process control and acceptance of these materials, as well as methods under development. State experience with these procedures, as well as discussions from the literature, are presented. There is growing use of rapid test methods for asphalt concrete and portland cement concrete in highway construction. This report of the Transportation Research Board describes the current state of the practice with respect to the use of rapid test methods for these materials. Experience with short-cut and rapid test procedures for process control and acceptance is summarized, and a general description of the methods, their advantages and disadvantages, and their time and labor requirements are discussed based on a review of the literature and a survey of the states. [More] | |
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186 - Supplemental Advance Warning Devices
1/1/1993
This synthesis will be of interest to traffic engineers, highway design engineers, and others concerned with the operation, safety, and design of the roadway environment. Information is presented on a variety of advance warning devices that are used by state and local agencies to advise motorists of unusual or dangerous road conditions. This synthesis describes the state of the art with respect to these devices. This report of the Transportation Research Board describes more than 340 such devices that have been applied and are in keeping with accepted traffic engineering principles, but are not presently included in the Manual on Uniform Traffic Control Devices (MUTCD). Both active and passive warning devices are presented in the following general categories: environmental conditions (e.g., snow and ice), heavy vehicles, school zones, pedestrian crossings, rail-highway grade crossings, roadway cross sections, congestion and queues, and others. The purpose and characteristics of each device are described, including any information available on their effectiveness, cost, or other features. A drawing of each device is shown to aid the reader in visualizing the device. [More] | |
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185 - Preferential Lane Treatments for High-Occupancy Vehicles
1/1/1993
This synthesis will be of interest to transportation planners, highway engineers, environmental personnel, highway design engineers, transit planners, highway administrators, and others concerned with the planning, design, and operational features of preferential high- occupancy vehicle (HOV) lanes on highways. Information is provided on the current and proposed state of the practice in North America. This synthesis describes the state of the art with respect to preferential treatment for HOVs on highways. This report of the Transportation Research Board provides information on long-distance facilities, such as barrier-separated, concurrent-flow (separated and nonseparated), and contraflow facilities, as well as on short-distance facilities, such as queue by-pass lanes. Planning, design, and operational features of each treatment are described. The issues and operating results are described, and specific case studies are included. [More] | |
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184 - Disposal of Roadside Litter Mixtures
1/1/1993
This synthesis will be of interest to maintenance managers, maintenance engineers, those responsible for environmental protection and waste management, and others concerned with the removal and disposal of litter from the roadside. Information is presented on the various aspects of the roadside litter problem, including the causes, amounts, costs, and hazards of litter disposal. This synthesis describes the state of the practice with respect to the magnitude and character of the roadside litter collection and disposal process. This report of the Transportation Research Board discusses various state practices with regard to roadside litter collection and highlights the volunteer efforts for roadside litter removal, such as Adopt-a-Highway and Keep America Beautiful. The disposal practices followed by state highway maintenance agencies are described, as are the issues associated with the available landfill disposal sites, incineration, and other disposal methods. Alternative strategies and deterrents to highway litter, such as litter reduction regulations and educational programs are presented, together with suggested strategies for recycling, reuse of materials, and smart purchase practices. Recommendations for future research are also included. [More] | |
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183 - Knowledge-Based Expert Systems in Transportation
1/1/1992
This synthesis will be of interest to engineering managers, design engineers, traffic engineers, computer personnel, and others interested in advanced computer applications for highway design and operations. Information is provided on the history of knowledge based expert systems (KBES), current applications of these systems in transportation departments, potential applications, and hardware and software requirements. Additionally, some detailed programming information from two operational expert systems is included. There is growing use of computers in transportation departments, and KBES represent an area in which several highway agencies are gaining experience and obtaining promising results. This report of the Transportation Research Board describes the current state of the practice with respect to KBES, as well as the historical development of expert systems and the more general field of artificial intelligence. Experience with expert systems in transportation in summarized, including discussions of expert systems in operation and in development, based on a review of the literature and a survey of the states and experts in this field. [More] | |
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182 - Performance and Operational Experience of Truck-Mounted Attenuators
1/1/1993
This synthesis will be of interest to maintenance, construction, and traffic engineers, and others interested in the use of safety apparatus for highway operations. Information is provided on the performance and operational experience of truck-mounted attenuators, including physical characteristics, test results, and guidelines for use. There is growing use of truck-mounted attenuators (TMAs) for highway traffic, maintenance, and construction operations. This report of the Transportation Research Board describes the current state of the practice with respect to the use of TMAs. Experience with TMA design is summarized, and field experience and guidelines for use are discussed based on a review of the literature and a survey of the states. [More] | |
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181 - In-Service Experience with Traffic Noise Barriers
1/1/1992
This synthesis will be of interest to highway environmental engineers, noise analysts, design engineers, maintenance personnel, planners, administrators, and others responsible for the design, selection, and maintenance of noise barriers or other traffic noise abatement policies. Information is provided on current state practice associated with noise abatement techniques and on the various products that are used. This synthesis describes the state of the art with respect to traffic noise abatement procedures, especially noise barriers. This report of the Transportation Research Board provides information on the design, construction and maintenance of both new (Type I) and retrofit ( Type II) noise barriers. The design elements that are addressed include materials, the selection process, service life, foundations, drainage, aesthetics, and safety. The construction section covers technical problems related to surface effects, durability, snow damage, and costs. Other noise abatement measures such as insulation and highway design alternatives are also addressed. The issue of public demand and availability funding is included, and recommendations are made to improve the situation. [More] | |
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180 - Performance Characteristics of Open-Graded Friction Courses
1/1/1992
This synthesis will be of interest to construction, maintenance, pavement design, and materials engineers, pavement contractors, and others interested in the use of open-graded friction courses (OGFC) as an asphalt concrete pavement wearing surface. Information is provided on performance benefits and limitations of OGFC, material and mixture properties, and current construction practices in use in the United States and Europe. Advances in mixture design and construction techniques have overcome several of the performance limitations identified in early applications of OGFC, as well as enhanced the performance benefits associated with OGFC use. This report of the Transportation Research Board describes the current state of the practice with respect to the use of OGFC. Experience with the design, construction, and performance of OGFC is summarized, based on a review of the literature, documentation of experience from applications in the U.S. and Europe, and site visits to several states. [More] | |
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179 - Latex-Modified Concretes and Mortars
1/1/1992
This synthesis wil be of interest to materials engineers, construction engineers, maintenance engineers, pavement contractors and others interested in the use of latex-modified mortars (LMM) and concretes ( LMC). Information is provided on material properties of various LMM and LMC, as well as current construction practices used for LMM and LMC. Potential applications for LMM and LMC are also included. The use of innovative modified portland cement mortars and concretes for construction and maintenance applications is growing. This report of the Transportation Research Board describes the current state of the practice with respect to the use of latex-modified portland cement concretes and mortars. The extent of use of each material (including case histories), based on results of surveys of state highway agencies and a review of the literature, is summarized. [More] | |
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178 - Truck Escape Ramps
1/1/1992
This synthesis will be of interest to highway design engineers, maintenance personnel, safety and enforcement officials, traffic engineers, and others responsible for the safe operation of large trucks on highways. Information is provided on the critical aspects of site location, design criteria, and maintenance procedures, and their relationship to truck escape ramp performance. The safety of truck drivers, other road users, and occupants of roadside properties is often imperiled by the combination of heavy trucks and steep downgrades on highways. Frequently, gearing down, applying the brakes, and using the retarding power of the engine are not sufficient to control the truck, and serious crashes can result. Many states have constructed truck escape ramps to safely remove runaway trucks from the traffic stream. This report of the Transportation Research Board provides information on the location, design, construction materials, geometrics, and construction costs of truck escape ramps. Operational considerations, such as descriptions of advance warning signs, traffic control devices at the ramp, and vehicle removal procedures are described. Information on frequency and type of usage, maintenance of the ramps, and driver-related issues is also included. [More] | |
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177 - Freeway Corridor Management
1/1/1992
This synthesis will be of interest to state and local traffic engineers, transportation planners, transit operators, law enforcement officials, public information agencies, and others responsible for the transportation elements of freeway corridors. Information is provided on the policies and procedures for freeway corridor management, and descriptions of a number of techniques and practices are presented. Traffic growth and increasing congestion on urban freeways require a comprehensive approach toward managing the complex elements of freeway operations. This report of the Transportation Research Board provides information on freeway corridor management strategies, the components of management, examples of effective applications of the strategies, and benefits of freeway corridor management. The management techniques that are discussed include freeway surveillance and control; corridor street surveillance and control; high-occupancy vehicle facilities and incentives; police enforcement and traffic control; hazardous material and other truck traffic restrictions; alternative route planning; motorist assistance patrols; motorist information techniques; and traffic management for recurrent congestion, for incidents, for special events, and for work zones. [More] | |
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176 - Bridge Paint: Removal, Containment, and Disposal
1/1/1992
This synthesis will be of interest to bridge painting contractors, bridge maintenance and construction engineers, environmental engineers, equipment manufacturers and suppliers, and others interested in bridge paint removal. Information is provided on current practices in bridge paint removal, containment, and disposal, with special attention paid to environmental, health, and cost issues, along with a discussion of current environmental regulations governing paint removal practices. The removal of bridge paint is a nationwide problem with sensitive environmental concerns and rapid changes in available technology and regulatory oversight. This report of the Transportation Research Board describes the current state of the practice for bridge paint removal, containment, and disposal, especially with regard to lead-based or other toxic paints. Additionally, current environmental regulations and health concerns in this area are examined. [More] | |
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175 - Moisture Damage in Asphalt Concrete
1/1/1991
This synthesis will be of interest to pavement designers, construction engineers, maintenance engineers, and others interested in avoiding or limiting moisture damage in asphalt concrete. Information is provided on physical and chemical explanations for moisture damage in asphalt concrete, along with a discussion of current practices and test methods for determining or reducing the susceptibility of various asphalt concrete components and mixtures to such damage. Moisture damage in asphalt concrete is a nationwide problem which often necessitates premature replacement of highway pavement surfaces. This report of the Transportation Research Board describes the underlying physical and chemical phenomena responsible for such damage. Current test methods used to determine the susceptibility of asphalt concretes, or their constituents, to moisture damage are described and evaluated. Additionally, current practices for minimizing the potential for moisture damage are examined. [More] | |
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174 - Storm Water Management for Transportation Facilities
1/1/1993
This synthesis will be of interest to highway design engineers, maintenance engineers, environmental personnel, administrators, and others responsible for the design, operation, and maintenance of stormwater management for highways and ancillary facilities. Information is presented on the basic hydrology needed to assess stormwater impacts and on the effectiveness of stormwater management techniques. Designers of highway facilities must consider stormwater management requirements within the context of both localized runoff impacts, as well as downstream effects of runoff. This report of the Transportation Research Board describes the management of both stormwater quantity and stormwater quality. Stormwater quantity includes an overview of methods of estimating runoff and management control practices. Stormwater quality management includes discussions of the most prevalent pollutants and best management practices (BMP) to minimize pollutants from transportation facilities. Various types of structural and non-structural methods are described, including their design considerations and efficiencies. Several stormwater management models are described, with special concern for highway applications. Highlights from the 1990 National Pollutant Discharge Elimination System (NPDES) permits are presented. [More] | |
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173 - Short-Term Responsive Maintenance Systems
1/1/1991
This synthesis will be of interest to maintenance managers, maintenance engineers, and others concerned with the periodic problems associated with the day-to-day maintenance of highways. Information is presented on discovery and response systems applicable to short-term responsive maintenance needs. The development and implementation of short-term responsive maintenance systems (STRMS) can be effective in handling permanent or temporary repairs. This report of the Transportation Research Board describes and discusses the short-term responsive maintenance systems in effect in several states. It describes how these special maintenance needs are detected, reported, evaluated, and managed, and notes how new technology can assist maintenance managers. [More] | |
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172 - Signal Timing Improvement Practices
1/1/1992
This synthesis will be of interest to traffic engineers, public officials, and others interested in developing improved traffic signal timing procedures. Information has been assembled on traffic signal timing software, resources required for timing, procedures for single intersections and coordinated systems, pedestrian intervals, and fine- tuning solutions. Traffic engineers need to know the comparative requirements and effectiveness of alternative traffic signal timing techniques. This report of the Transportation Research Board describes these techniques, presents the general principles for application, including source material for more detailed information, and discusses the issues associated with traffic signal timing alternatives. It should be noted that, while traffic engineers frequently use standards developed by the American Association of State Highway and Transportation Officials, the Federal Highway Administration, or other agencies in making engineering judgments, they are always well advised to protect themselves by carefully supporting the bases of their decisions with factual findings and documenting the reasons for the decisions. [More] | |
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171 - Fabrics in Asphalt Overlays and Pavement Maintenance
1/1/1991
This synthesis will be of interest to pavement designers, maintenance engineers, and others interested in methods and procedures for reducing reflection cracking of asphalt overlays. Information is provided on the use of paving fabrics and membranes in pavement rehabilitation. Reflection cracking of pavement overlays results in decreased pavement performance with respect to ride quality, structural support, skid resistance, and safety. The use of fabrics is one of the alternatives that are available to reduce or delay reflection cracking. This report of the Transportation Research Board describes the experiences of agencies in the use of fabrics and membranes for reduction of reflection cracking. [More] | |
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170 - Managing Urban Freeway Maintenance
1/1/1990
This synthesis will be of interest to maintenance engineers, traffic engineers, and others interested in the management aspects of maintaining urban freeways. Information is provided on techniques and procedures used by agencies to improve and speed up maintenance procedures, schedule work, and coordinate freeway lane closures. Maintenance of aging urban freeways is difficult because of the high volumes of traffic on these facilities. This report of the Transportation Research Board describes techniques and procedures that highway agencies are using, such as reducing work time and scheduling work for off-peak periods, to minimize traffic delays while freeway maintenance is performed. [More] | |
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169 - Removing Concrete from Bridges
1/1/1991
This synthesis will be of interest to maintenance engineers, bridge engineers, and others interested in methods and procedures for removing concrete from bridges. Information is provided on equipment and procedures used by states to remove concrete from highway bridges. Repairing structural concrete involves removal and replacement of deteriorated concrete. This report of the Transportation Research Board describes the equipment and procedures used for both complete and partial removal of concrete from bridge decks and substrates. [More] | |
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168 - Contract Management Systems
1/1/1990
This synthesis will be of interest to administrators, contract officers, and others interested in using consulting firms to manage a transportation agency's work activities -- ranging from a single project to a complete spectrum of work. Information is provided on various aspects of contract management systems, including examples of use of each aspect in several agencies. An increasing workload coupled with reduced staff size have caused state highway agencies to turn to private enterprise to accomplish work that has traditionally been done in-house. This report of the Transportation Research Board describes various aspects of the use of consultants to manage a highway agency's work and gives specific examples of use of each aspect in several agencies. [More] | |
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167 - Measurements, Specifications, and Achievement of Smoothness for Pavement Construction
1/1/1990
This synthesis will be of interest to construction engineers, pavement designers, contractors, and others interested in construction of new highway pavements with smooth surfaces. Information is provided on the various devices and specifications that are being used to obtain smooth pavements. The public rates a pavement primarily on its smooth-riding characteristics and highway agencies recognize that constructing smooth pavements results in fewer problems later and lower annual maintenance costs. This report of the Transportation Research Board describes the devices and specifications highway agencies use to ensure that newly constructed pavements will provide a smooth ride. [More] | |
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166 - Traffic Signal Control Equipment: State of the Art
1/1/1990
This synthesis will be of interest to traffic engineers and others interested in the capabilities of currently available equipment for traffic signal control. Information is provided on functions and operations of controller assemblies, displays, detectors, communications, and computerized system masters. Traffic engineers need to know the functional capabilities of the various types of signal control equipment in order to select appropriate equipment for a specific application. This report of the Transportation Research Board describes the functions of each type of equipment and how it works, and gives advantages, disadvantages, and limitations. [More] | |
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165 - Transportation Telecommunications
1/1/1990
This synthesis will be of interest to administrators, operating personnel, and others interested in the management and operation of telecommunications systems in transportation agencies. Information is provided on the fundamentals of telecommunications, types of systems available, current uses in state DOTs, and implementation procedures and alternatives. Most departments of transportation have telephone and radio systems in use for communications with their own personnel and with the public. This report of the Transportation Research Board describes those systems as well as other telecommunications options that are in use by transportation agencies or are available for their use. [More] | |
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164 - Measures to Curtail State Fuel Tax Evasion
1/1/1990
This synthesis will be of interest to finance officers, administrators, legislators, and others interested in the actions that states take to stem evasion of highway fuel taxes. Information is presented on the types of schemes that are being used to evade paying fuel taxes and on practices that have been successful in eliminating those schemes and increasing fuel tax revenues. With shortages of funds to meet current and future highway needs, it is important for states to stem evasion of fuel taxes. This report of the Transportation Research Board describes some of the schemes that have been devised to evade paying fuel taxes and a number of successful practices that states have used to foil those schemes. [More] | |
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163 - Innovative Strategies for Upgrading of Personnel by State Transportation Departments
1/1/1990
This synthesis will be of interest to administrators, personnel officers, and others interested in methods for upgrading capabilities of DOT employees through training and development. Information is provided on programs and processes used by states for recruitment, training (both for new employees and for retraining of existing employees), and management and career development. High rates of retirement and a shrinking supply of civil engineering graduates mean that state DOTs need to expand and improve their professional staffs to meet an increasing workload. This report of the Transportation Research Board describes the programs used by states to recruit new employees, train them, develop their capabilities, and provide management and career development opportunities. [More] | |
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162 - Signing Policies, Procedures, Practices, and Fees for Logo and Tourist-Oriented Directional Signing
1/1/1990
This synthesis will be of interest to traffic engineers, planners, and others interested in providing directional guidance to motorists. Information is provided on policies and procedures used by many states in establishing and operating signing programs that provide information on available motorist services and tourist attractions. On Interstate and other controlled-access highways, signs that show the logos of nearby gas, food, lodging, and camping facilities provide valuable assistance to motorists. This report of the Transportation Research Board describes the policies and procedures used by states to install and maintain those signs as well as other types of signs that direct motorists to tourist services and attractions. [More] | |
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161 - Computer-Aided Design and Drafting Systems
1/1/1990
This synthesis will be of interest to administrators, designers, computer personnel, and others interested in the operation and management of computer-aided design and drafting (CADD) systems. Information is provided on selection and implementation of CADD systems, current use in state departments of transportation (DOTs), and issues involved in managing a CADD system and CADD operators. Most state DOTs either have or plan to acquire CADD systems to improve their design, drafting, and mapping operations. This report of the Transportation Research Board describes the processes for selecting and implementing a CADD system, current practices of state DOTs in applying and using CADD, and training and performance issues with respect to CADD personnel. [More] | |
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160 - Cold-Recycled Bituminous Concrete Using Bituminous Materials
1/1/1990
This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for reconstructing or rehabilitating bituminous pavements. Information is provided on the processes and procedures used by a number of states to recycle asphalt pavements in place without application of heat. Since 1975 a growing number of state highway agencies have reconstructed or rehabilitated asphalt pavements by recycling the old pavement in place. This report of the Transportation Research Board describes the processes used for cold in-place recycling, including construction procedures, mix designs, mixture properties, performance, and specifications. [More] | |
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159 - Design and Construction of Bridge Approaches
1/1/1990
This synthesis will be of interest to geotechnical, bridge construction, and maintenance engineers and others interested in design, construction, and maintenance of embankment approaches to bridge abutments. Information is provided on available techniques to minimize problems associated with the bump at the end of the bridge. The transition from a roadway to a bridge structure entails design, construction, and maintenance problems. This report of the Transportation Research Board describes those problems as well as the many solutions that are applicable to specific situations. [More] | |
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158 - Wet-Pavement Safety Programs
1/1/1990
This synthesis will be of interest to pavement engineers, safety officers, and others interested in wet-pavement safety programs. Information is provided on the programs used by a number of agencies in gathering data and correcting areas of potential wet-weather accidents. Wet-pavement accidents continue to be of concern to highway agencies. This report of the Transportation Research Board summarizes agencies' programs in areas such as accident reporting, vehicle testing, friction testing, corrective actions for problem areas, and tort liability and gives some general guidelines for the content of a wet-pavement safety program. [More] | |
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157 - Maintenance Management of Street and Highway Signs
1/1/1990
This synthesis will be of interest to traffic engineers, maintenance managers, sign shop supervisors, and others interested in the maintenance of street and highway signs. Detailed information is presented on the current practices of state and local governments in managing the maintenance of street and highway signs within their jurisdictions. The maintenance of street and highway signs is viewed as a means for improving the effectiveness of a signing system. This report of the Transportation Research Board describes the maintenance practices of several state and local highway agencies along with the rationale for those practices. It covers inspection, refurbishing, and replacement practices, along with information on equipment and personnel requirements. [More] | |
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156 - Freeway Incident Management
1/1/1990
This synthesis will be of interest to traffic engineers, planners, and others interested in how highway agencies deal with freeway incidents. Information is provided on the procedures and processes that highway agencies use to respond to traffic congestion caused by incidents on freeways. Congestion on freeways frequently is caused by incidents such as stalled vehicles or accidents that reduce the capacity of the freeway below the level of demand. This report of the Transportation Research Board describes the procedures and processes used by states to respond to traffic congestion caused by incidents on freeways. [More] | |
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155 - Freeway Guide Sign Replacement: Policies and Criteria
1/1/1991
This synthesis will be of interest to traffic engineers, planners, and others interested in making sure that motorists' needs for directional information on freeways are being met. Information is provided on policies and procedures used by states in evaluating freeway guide signs and replacing those that are outdated or deteriorated. Many signs on freeways and other controlled-access highways have exceeded their service life and are no longer serving motorists' needs. This report of the Transportation Research Board describes the policies, proceduress, and criteria used by states for freeway sign evaluation and replacement programs. [More] | |
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154 - Recycling Portland Cement Concrete Pavements
1/1/1989
This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for recontstructing portland cement concrete (PCC) pavements. Information is provided on the processes and procedures used by a number of states in using PCC pavement as aggregate in reconstructed concrete pavement. Since 1975 a number of state highway agencies have reconstructed concrete pavements using the old PCC as aggregate in the new pavement. This report of the Transportation Research Board describes the processes used on various projects in several states, giving details of construction procedures, as well as test results on various properties of the recycled aggregates and the resultant concrete. [More] | |
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153 - Evolution and Benefits of Preventive Maintenance Strategies
1/1/1989
This synthesis will be of interest to maintenance managers, maintenance engineers, and others concerned with the implementation and evaluation of preventive maintenance strategies. Detailed information is presented on the formulation, use, and assessment of this type of maintenance strategy. Preventive maintenance strategies are viewed as a means for improving effectiveness of state highway maintenance programs. This report of the Transportation Research Board describes the preventive maintenance practices of several states, along with the rationale for these practices. It covers the history of preventive maintenance along with funding considerations, strategy development, and cost analysis. Recommendations regarding current practices and future funding schemes are also included. [More] | |
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152 - Compaction of Asphalt Pavement
1/1/1989
This synthesis will be of interest to construction and materials engineers, paving contractors, equipment manufacturers, and others who are involved in assessing the performance of asphalt pavements. Information is presented on various issues related to compaction of asphalt pavements. Compaction is one of the most important factors affecting the performance of asphalt pavements. This report of the Transportation Research Board describes the theory, methods, equipment, and specifications related to the compaction of asphalt pavements. A brief history of, the importance of, and factors affecting compaction are also discussed. Construction influences, density measurements, and trends are also considered. [More] | |
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151 - Process for Recapitalizing Highway Transportation Systems
1/1/1989
This synthesis will be of interest to administrators, fiscal officers, and programming and planning officials in large highway transportation organizations, as well as legislators and others interested in the planning and programming of highway transportation capital improvement projects. Information is presented on strategies related to project selection and budgeting for recapitalizing highway transportation systems. There is increasing pressure on state transportation organizations to be more productive with existing resources. This report of the Transportation Research Board describes processes for planning and implementing highway capital improvements. General frameworks for this process are discussed along with specific examples of how it is done by several states. Observations on the state of the practice are given along with some information on possible future trends. [More] | |
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150 - Technology Transfer in Selected Highway Agencies
1/1/1989
This synthesis will be of interest to administrators, technology transfer officials, college/university educators, and others concerned with technology transfer. Information is presented on how information about new technology is disseminated and how the use of new technology is actively promoted. Technology transfer is an integral part of the research and engineering functions. This report of the Transportation Research Board describes the technology transfer process as it is carried out in state highway departments and Rural Technology Assistance Program technology transfer centers. It critically discusses various mechanisms that are used to share information (e.g., research reports, short courses, videotapes, etc.) with interested users. Methods for accelerating the process by which new technology information can be shared and used are also considered. [More] | |
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149 - Partnerships for Innovation: Private-Sector Contributions to Innovation in the Highway Industry
1/1/1989
This synthesis will be of interest to administrators, researchers, and private-sector business leaders in the highway industry. Information is presented on how the public and private sectors can promote innovation in the highway field. The highway industry needs to encourage on a national and state level the introduction of innovative new technologies in design, construction, operations, and maintenance. This report of the Transportation Research Board describes the current practices of federal, state, provincial, and local governments to foster innovation in the highway industry. Reasons for the very limited successes of the past are discussed, and suggestions for creating an industry environment in which innovation will take place are made. [More] | |
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148 - Indicators of Quality in Maintenance
1/1/1989
This synthesis will be of interest to maintenance managers, maintenance engineers, and others concerned with the development of quality indicators for maintenance management. Detailed information is presented on the formulation and use of these qualtiy indicators. Indicators of quality are an integral part of any maintenance management system. This report of the Transportation Research Board describes and discusses the use of quality standards to assess the effectiveness of highway maintenance activities. It examines the use of these standards in the context of traditional management techniques and maintenance management systems. The trade-offs between quality and quantity standards are also considered. [More] | |
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147 - Treatment of Problem Foundations for Highway Embankments
1/1/1989
This synthesis will be of interest to geotechnical engineers, highway designers, construction engineers, planners, and others interested in constructing or widening highway embankments on problem foundations. Information is presented on site investigation and testing and on the various construction alternatives that are available when a highway must cross a problem foundation site. Construction over problem soil areas requires extensive site investigations and comparative design analyses to evaluate alternatives. This report of the Transportation Research Board updates and expands synthesis 29, which was published in 1973. It discusses the treatments and construction procedures that can be used to construct highway embankments over areas of soil that would otherwise not support such embankments. It describes site investigations, design analyses, and the kinds of treatments currently being used, including where they are applicable and the advantages and disadvantages of each. [More] | |
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146 - Use of Consultants for Construction Engineering Inspection
1/1/1989
This synthesis will be of interest to construction engineers, contractors, administrators and others concerned with using consultants as a replacement for or as a supplement to agency staffing on highway construction projects. Information is presented on determining the need for consultants as well as methods for hiring them and supervising and monitoring their work. In recent years, highway agency personnel reductions have meant that consultants have had to be engaged to adequately staff construction projects. This report of the Transportation Research Board discusses how highway agencies are using consultants for construction engineering and inspection including hiring, qualifications, and agency oversight and control. [More] | |
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145 - Staffing Considerations in Construction Engineering Management
1/1/1989
This synthesis will be of interest to construction engineers, contractors, administrators, and others interested in providing an adequate level of staffing on highway construction projects. Information is presented on determining the number of personnel needed, as well as the qualifications and training needed. Agency testing and inspection along with contractor staffing and quality control are important contributors to the quality of highway construction. This report of the Transportation Research Board discusses how agencies and contractors determine the number of personnel needed on a highway construction project as well as the qualifications and training needed for those personnel. [More] | |
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144 - Breaking/Cracking and Seating Concrete Pavements
1/1/1989
This synthesis will be of interest to pavement designers, maintenance engineers, and others interested in reducing reflection cracking of asphalt overlays on portland cement concrete (PCC) pavement. Information is presented on the technique of breaking or cracking of the concrete pavement into small segments before overlaying with asphalt concrete. Asphalt concrete overlays on existing PCC pavements are subject to reflection cracking induced by thermal movements of PCC pavement. This report of the Transportation Research Board discusses the technique of breaking/cracking and seating of the existing PCC before an overlay as a means to reduce or eliminate reflection cracking. [More] | |
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143 - Uniformity Efforts in Oversize/Overweight Permits
1/1/1988
The purpose of this synthesis is to summarize efforts directed at achieving national uniformity in the basic elements of oversize and overweight permit functions for nondivisible loads. Key results of research efforts on this topic over the past 20 years are summarized. Also described are six state-level efforts, three national-level efforts, and one industry-level effort aimed at developing common, multistate agreements. One state-level effort in particular appears to provide a positive experience in developing a common set of permit procedures: five New England states signed an agreement on April 28, 1987, and expect to have a common set of permit procedures fully operational by early 1989. [More] | |
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142 - Methods of Cost-Effectiveness Analysis for Highway Projects
1/1/1988
This synthesis presents a brief overview of the traditional economic- analysis methods that have been used in the analysis of highway engineering alternatives. Then, because the earliest work in cost- effectiveness as a structured methodology was in the Defense Department, three basic criteria commonly used by the military are presented: maximize net benefits; minimize the amount of resources required; and maximize the level of service. Data from more than 40 states was assembled to: compare the different methods of cost- effectiveness analysis highway personnel are using and determine which methods are most commonly used and which methods are most innovative; and develop a format that will assist highway personnel in selecting a method to set priorities and make decisions regarding a variety of highway programs or projects. The methods reported are categorized as follows: (1) systems analysis packages; (2) sufficiency-rating-based packages; (3) standard benefit/cost analysis; (4) pavement management systems; (5) operations cost-effectiveness measures; (6) construction cost-effectiveness measures; (7) maintenance cost-effectiveness measures; and (8) private investment cost-effctiveness measures. Examples in each of the categories are presented to show how each category could be very useful in the standard operating practices of every state DOT or highway department. [More] | |
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141 - Bridge Deck Joints
1/1/1989
This synthesis will be of interest to bridge designers, maintenance engineers, and others concerned with designing and maintaining bridge deck joints. Information is presented on the types of deck joints used in bridges and on the design of bridges without joints. Bridges are continually moving and thus need either some type of deck joint or an integral design to accommodate this movement. This report of the Transportation Research Board describes the types of deck joints being used, the problems with these joints, and how integral construction-- bridge decks without joints--can be used to avoid joints. [More] | |
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140 - Durability of Prestressed Concrete Highway Structures
1/1/1988
This synthesis will be of interest to bridge designers, materials engineers, maintenance engineers, and others concerned with the durability of prestressed concrete bridges. Information is presented on the factors affecting the durability of prestressed concrete. Prestressed concrete bridges require special attention because the capacity of the structure is strongly dependent on the prestressing force. This report of the Transportation Research Board reviews the factors affecting the durability of prestressed bridge components and describes methods of detecting and assessing deterioration, preventive maintenance, repair, and methods of improving durability in new structures. [More] | |
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139 - Pedestrians and Traffic Control Measures
1/1/1988
This synthesis will be of interest to traffic engineers, safety engineers, and others concerned with pedestrian safety. Information is presented on the traffic-control measures being used by states and local agencies to enhance pedestrian safety. Approximately 15 to 20 percent of all highway fatalities are pedestrians, and although most pedestrian accidents occur in urban areas, all agencies should pay more attention to the needs of pedestrians. This report of the Transportation Research Board describes and discusses more than 20 traffic-control measures and their effects on pedestrian safety, including the advantages and disadvantages of each and the conditions under which each is most and least likely to be of benefit. [More] | |
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138 - Pavement Markings: Materials and Application for Extended Service Life
1/1/1988
This synthesis will be of interest to maintenance engineers, traffic engineers, materials engineers, and others concerned with pavement- marking materials. Information is presented on the various types of traffic-marking materials being used by states to obtain extended service life. Enormous quantities of paint, thermoplastics, glass beads, raised markers, and other materials are used every year to mark the highways of the United States. This report of the Transportation Research Board describes the need for markings, preparation of the pavement surface, and the various types of paint, thermoplastic, thermosets, tapes, and raised markers in current use. [More] | |
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137 - Negotiating And Contracting For Professional Engineering Services
1/1/1988
This synthesis will be of interest to designers, highway administrators, and others concerned with hiring consultants to prepare designs or perform construction inspection. Information is presented on the procedures and processes used by the states in negotiating and contracting for professional engineering services. In recent years there has been a sharp increase in the use of consultants by the states for design and for the inspection of construction. This report of the Transportation Research Board describes the processes used by the states in negotiating and contracting for professional engineering services, including determining needs, listing qualified firms, evaluating qualifications, negotiating terms and prices, and evaluating performance. [More] | |
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136 - Protective Coatings for Bridge Steel
1/1/1987
This synthesis will be of interest to bridge designers, materials engineers, maintenance engineers, and others concerned with coating systems used to protect bridge steel from corrosion. Information is presented on the causes of steel corrosion and the types of surface preparation and coatings used to protect the steel. Steel bridges need some type of protective coating to keep them from corroding. This report of the Transportation Research Board explains the mechanisms of steel corrosion and how coatings protect the steel, discusses the need for and types of surface preparation, and describes twenty types of available coating systems under three general categories: inhibitive systems, zinc-rich (sacrificial) systems, and barrier systems. [More] | |
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135 - Pavement Management Practices
1/1/1987
This synthesis will be of interest to pavement designers, maintenance engineers, and others responsible for the management of highway pavements. Information is presented on pavement management systems - the established, documented procedures used to treat all activities involved in providing and sustaining pavements in an acceptable condition. As highway agencies focus more attention on maintenance and rehabilitation of highway networks, the use of some form of a pavement management system becomes increasingly important. This report of the Transportation Research Board describes the features, applicability, and use of a pavement management system and recommends five general steps for implementing a new pavement management system or improving an existing system. [More] | |
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134 - D-Cracking Of Concrete Pavements
1/1/1987
This synthesis will be of interest to pavement designers, materials engineers, maintenance engineers, and others concerned with design, construction, and maintenance of portland cement concrete pavements. Information is presented on the causes of and potential means for minimizing D-cracking of concrete pavements. In certain areas of the country, the coarse aggregates used in concrete pavements are susceptible to disintegration from repeated freezing and thawing. This report of the Transportation Research Board describes the mechanisms of D-cracking, summarizes known materials-acceptance and design techniques that can minimize D-cracking of new pavements, and describes rehabilitation techniques for existing pavements. [More] | |
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133 - Integrated Highway Information Systems
1/1/1987
This synthesis will be of interest to designers, traffic engineers, planners, and others concerned with the collection and use of highway data. Information is presented on current practices of states in correlating or linking highway-related data maintained in various types of independent computer files. As computer technology has enabled data collection and storage to grow, data files have been developed independently in various units within highway agencies. This report of the Transportation Research Board describes the integrated highway information systems used by states to link independent data files so that the agency as a whole (as well as the individual units) will benefit from the ability to see and compare information from the various files. [More] | |
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132 - System-Wide Safety Improvements: An Approach To Safety Consistency
1/1/1987
This synthesis will be of interest to safety engineers, highway planners, and others concerned with the procedures used by states to plan and program safety improvements. Information is presented on current practice of states in using system-wide improvements to provide safety consistency. The primary purpose of system-wide safety improvements is to increase safety by improving roadway consistency - to minimize violations of driver expectancy and to avoid or reduce injury and damage that occur when a vehicle leaves the roadway. This report of the Transportation Research Board describes the system-wide and spot approaches to safety improvement, explains strategies and programs for system-wide improvements, and gives general guidelines for a program of improving roadway consistency through system-wide safety improvements. [More] | |
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131 - Effects of Permit and Illegal Overloads on Pavement
1/1/1987
This synthesis will be of interest to pavement designers, highway administrators, and others concerned with pavement design, permit issuance and fees for overloaded trucks, and enforcement of truck weight laws. Information is presented on the effects that overloads have on pavements and on the methods of accommodating or controlling overloads. Highway pavements are designed for legal axle loads, and loads above these will significantly shorten pavement life. This report of the Transportation Research Board describes the effects on pavements of loads greater than those used in design, gives information on permit issuance and fees for overloaded vehicles, and describes the difficulties in enforcing truck weight laws. [More] | |
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130 - Traffic Data Collection and Analysis: Methods and Procedures
1/1/1986
This synthesis will be of interest to traffic engineers, highway planners, and others concerned with the collection of traffic data for traffic engineering studies, for long-range planning, and for evaluation of traffic law enforcement. Information is presented on current practice in traffic data collection and analysis. Although types of highway traffic data collected over the past 50 years have not changed significantly, the quantities, analysis procedure, and presentations of these data have changed as a result of changing policies, operational concerns, and capabilities resulting from new technologies. This report of the Transportation Research Board describes the technology (both hardware and software) that is being used for traffic data collection, and discusses technological advances that have not yet been applied to the acquisition and presentation of traffic data. [More] | |
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129 - Freezing and Thawing Resistance of High-Strength Concrete
1/1/1986
Recent developments have made a new generation of high-strength concrete a viable material for routine construction. The two principal developments are high-range water-reducing admixtures, which permit the placement of concrete of very low water-cement ratio, and silica fume, a pozzolan of extremely high fineness. The advent of this high- strength concrete has put requirements for strength and durability in conflict. Because entrained air reduces the strength of concrete, builders seek to eliminate or limit the use of entrained air. There are those who argue that high-strength concrete is of such a quality that entrained air is unnecessary. Much of the high-strength concrete currently being used is in buildings, where the question of durability is minor. The question, however, cannot be avoided in exposed highway structures. Service records of non-air-entrained high-strength concrete exposed to freezing are not conclusive. Hence, this report synthesizes the available knowledge on the subject. Its aim is to provide guidance to those who wish to use high-strength concrete in typical highway applications and to indicate where further information is needed. [More] | |
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128 - Methods for Identifying Hazardous Highway Elements
1/1/1986
A project is reported which surveyed the methods that are currently used by highway agencies to identify and treat hazardous highway elements and to determine which methods have been most successful. The synthesis specifically focuses on: (a) defining a hazardous highway element, (b) discussing methods of identifying elements that are strongly associated with accident frequency or severity, and (c) addressing funding issues and problems relative to these elements. The establishment of priorities for improving highway elements is discussed, and agency data collection problems and limitations are noted. Conclusions drawn from the study are presented and recommendations are made. [More] | |
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127 - Use of Fly Ash in Concrete
1/1/1986
This synthesis summarizes available information concerning the use of fly ash in hydraulic-cement concrete, and attempts to establish consensus concerning a number of applications relating to highway construction. Fly ash marketing procedures are briefly reviewed, and the amount of fly ash now being used is summarized. The results are reported of a questionnaire survey of the status of the use of fly ash concrete (FAC) in each state of the U.S. and the provinces of Canada. There is an increase in FAC use since 1980. This trend is aided by the development of a flyash industry. Trends also indicate a developing technology that will be oriented around performance of the hydraulic cement concrete. Currently, most states view the proportioning of of FAC from the standpoint of the amount of portland cement to be replaced by the fly ash and have maximum replacement limits. It has been noted that the same fly ash with different cements may react differently and develop different early and ultimate strengths. The need is emphasized for preliminary tests to establish optimum proportioning of ingredients in the concrete using materials from the sources to be supplied to the job. [More] | |
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126 - Equipment for Obtaining Pavement Condition and Traffic Loading Data
1/1/1986
Equipment is identified that is associated with the collection of structural capacity, surface distress, friction, roughness, and traffic loading data. Current practices costs, and maintenance requirements are presented. Advantages and disadvantages of particular types of equipment are also presented and new equipment developments are briefly discussed. Currently, structural capacity is evaluated by a measure of surface deflection under a slow-moving, vibrating, or falling load. The Benkelman beam is the most commonly used equipment. Techniques for measuring physical distress and types of distress catalogued vary by agency and depend on the purpose for which the information is collected. Pavement surface friction is mostly measured with the locked-wheel-trailer procedure or the yaw mode procedure. Ride quality is related to the roughness of the pavement and is measured by either response-type equipment or profilometer. Equipment for collecting traffic volume and traffic weights are portable counters, fixed counters, weigh-in-motion devices, portable scales, and permanent weigh stations. [More] | |
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125 - Maintenance Activities Accomplished by Contract
1/1/1986
Of 75 agencies surveyed for this synthesis, 71 are using contract maintenance to some extent. The activities most commonly contracted are maintenance overlays, bridge painting, bridge repairs, pavement sealing, and rest area maintenance. There was a wide range in the level of contracting. Most agencies believed that contracting was cost- effective, that quality of work was satisfactory, and that contractors were satisfactory in their response to emergencies. In some agencies, the use of contract maintenance is dictated by legal or policy requirements, such as a requirement to contract if expenditures exceed a set threshold. This publication discusses the pros and cons of contracting and reviews current practices in the area. The decision process, including the determination of the need to contract, the feasibility of contracting, and the desirability for so doing, as well as the costs are covered. The organizing for contracting and the implementation of the contracting process are described. Research needs related to guide specifications, and inspection and quality control are noted. [More] | |
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124 - Use of Weigh-in-Motion Systems for Data Collection and Enforcement
1/1/1986
This report describes how weigh-in-motion (WIM) scales can be used to collect data on truck weights, what uses those data have, and the advantages and disadavantages of using WIM systems to collect the data. The history of WIM development is briefly described, and WIM data needs and uses are reviewed. WIM data requirements are considered, and WIM technology is described. User experiences are presented, and current programs and research are noted. [More] | |
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123 - Bridge Designs to Reduce and Facilitate Maintenance and Repair
1/1/1985
An attempt is made to develop a body of information on bridge design concepts and details that will lead to reduced life-cycle maintenance costs and facilitate repair procedures. This includes accessibility, material selection, corrosion protection, ease of rehabilitation, and continued bridge use during retrofit. Concepts to increase communication among design, construction, and maintenance personnel to improve maintenance are proposed. A literature review was made to gather information on bridge design concepts and details related to maintainability. Chapter 1 of this report introduces the study and chapters 2 through 5 present the engineering related concerns: accessibility, design and use of materials, corrosion protection, and designing for rehabilitation and continued use. Chapter 6 presents administrative-related concerns such as effective organizational communication. Conclusions are presented in chapter 7. [More] | |
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122 - Life-Cycle Cost Analysis of Pavements
1/1/1985
This synthesis will be of interest to pavement designers, maintenance engineers, and other concerned with selection of pavement designs and pavement rehabilitation alternatives. Information is presented on how life-cycle can be used to select the alternative that is least expensive over time. (Author) [More] | |
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121 - Energy Conservation in Transportation
1/1/1985
This synthesis is organized to present information on conservation measures by mode and by approach (i.e., policy, technology, operations). Distinctions are made between those measures or technologies that can be implemented now as compared to those that will be available in the future. Only limited attention is given to air, marine, pipeline, and other modes. Finally, an attempt is made to identify gaps in present knowledge of energy conservation techniques in order to define needed research. [More] | |
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120 - Professional Resource Management and Forecasting
1/1/1985
This synthesis will be of interest to administrators, personnel managers, and others concerned with recruiting, promoting, training, and retaining engineers and other professional staff in highway agencies. Information is presented on planning for professional staff needs and on the elements of a professional resource program, including examples of practice in several states. (Author) [More] | |
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119 - Prefabricated Bridge Elements and Systems
1/1/1985
This synthesis will be of interest to bridge designers, maintenance and construction personnel, and others concerned with the design, maintenance, and rehabilitation of bridges. Information is presented on the use of prefabricated elements that can be used to construct new bridges or rehabilitate old ones. (Author) [More] | |
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118 - Detecting Defects and Deterioration in Highway Structures
1/1/1985
The need to detect defects and deterioration in highway structures ranges from reasons of safety to the prediction of load capacity to the information base for a bridge manangement system. The emphasis here is on test procedures that can be used in the field and guidance is given in interpreting the significance of measured values. Although it is usually possible to detect deterioration in a component of a structure, it is often difficult to assess the effect of the deterioration on the load-carrying capacity of the structure. Often, full scale testing is justified to measure the overall condition of a structure. A survey of current practices revealed that concrete structures are being tested more extensively than steel or timber structures. [More] | |
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117 - Toll Highway Financing
1/1/1984
This synthesis will be of interest to highway financial officers, administrators, and others concerned with financing highway construction, maintenance, and operation. Information is presented on the history, recent trends and developments, and general considerations for financing a highway project through use of tolls. (Author) [More] | |
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116 - Asphalt Overlay Design Procedures
1/1/1984
This synthesis will be of interest to pavement designers and others concerned with the design of asphalt concrete overlays. Information is presented on reasons for overlaying a pavement and on the vaious methods available for design of an asphalt overlay. A pavement overlay may be required because of inadequate ride quality, excessive pavement distress, reduced friction between tire and pavement, high user costs, or inadequate structural capacity for planned use. This report of the Transportation Research Boad discusses the current methods used for designing asphalt concrete overlays with emphasis on deflection-based and analytical procedures. (Author) [More] | |
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115 - Reducing Construction Conflicts Between Highway and Utilities
1/1/1984
As highways are constructed, widened, and rebuilt to meet the needs of the public and as utilities are installed, maintained, and improved to meet customer demand, it is inevitable that there will be conflicts between the highway agency and the utility companies. Most of these conflicts are resolved before construciton begins but it is estimated that as much as $120 million per year of highway contract claims results from utility conflicts. Construction problems caused by utility conflicts result when utility locations are unknown or when utility removal is late. Both interfere with contractors' schedules and cause delays, and thus may result in a claim. In general, utility companies report good relations with highway agencies although the relationship varies from state to state. Both highway agencies and utilities believe that the better the relationship, the fewer conflicts and claims. Agencies with effective coordination usually have a manual that sets out in detail the responsibilities and procedures for coordination. Many agencies also participate in liaison committees that foster coordination between these two groups. Another method of coordinationis involvement of utilities in pre-bid meetings witth contractors. This allows all parties to understand what has to be done, when it needs to be done, and who is to do it. There is a need for effective delineation of the locations of buried facilities. This would prevent accidental damage during construction. The best method of avoiding conflicts is good communication between highway agencies and utility companies. Communication is helped where each organization has only one office that is responsible for coordination regardless of whether the highway agency or the utility company initiates an action. (Author) [More] | |
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114 - Management of Traffic Signal Maintenance
1/1/1984
This synthesis will be interest to traffic engineers, maintenance engineers, and others responsible for managing the maintenance of traffic signal equipment and systems. Information is presented on the management aspects of signal maintenance including personnel, organization, costs, and control. (Author) [More] | |
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112 - Cost-Effectiveness of Hot-Dip Galvanizing for Exposed Steel
1/1/1984
This synthesis will be useful to materials engineers and others interested in the use of hot-dip galvanizing for protection of exposed steel. Information is presented on the performance of hot-dip galvanizing and on economic considerations in selecting a coating for exposed steel. (Author) [More] | |
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111 - Distribution of Wheel Loads on Highway Bridges
1/1/1984
The objective of this synthesis is to develop information on distribution of wheel loads on highway bridges. Live-load distribution among the various components of a floor system is one of the key elements in determining member size, strength, and serviceability of a bridge. The synthesis includes a summary of the current specification criteria and their background, a brief overview of available research, an evaluation of the current load-distribution practices in both design and rating, as well as alternative methods for load distribution, and identification of all sections affected by and related to the load distribution provisions. Emphasis has been placed on the criteria for the supporting member, although consideration is given to the interaction within decking systems and between the superstructure and the substructure. [More] | |
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110 - Maintenance Management Systems
1/1/1984
Maintenance management systems (MMS) began in the 1950s with research into management of maintenance operations in Connecticut and Iowa. The idea of applying management principles to highway maintenance gained popularity as the systems were better defined and the benefits became obvious. Maintenance management is a method of controlling resources to accomplish a predetermined level of service through planning, budgeting, scheduling, reporting and evaluating. Planning consists of defining maintenance activities, compiling a features inventory, establishing priorities, establishing quality, quantity, performance standards and compiling cost data. [More] | |
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109 - Highway Uses of Epoxy with Concrete
1/1/1984
Many agencies have used epoxies since 1954 for various purposes such as bonding concrete, filling cracks, anchoring bolts, etc. The results of this use has varied depending primarily on its application. Reasons for its success or failure are noted. An epoxy is made by mixing a resin with a curing agent. Many different resins, curing agents, and modifiers are available. The type and amount of curing agent modifier used affects the properties of the aired epoxy system. Among the properties that are affected are viscosity, cure rate, shrinkage, flexibility, plasticity, thermal expansion, strength, and appearance. Specifications and tests for epoxies have been developed by AASHTO, ASTM and ACI. This publication reviews highway uses of eposy, and discusses in detail, the material itself--it's handling, it's properties, tests and specifications. A conclusion, references, and bibliography are also included. [More] | |
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108 - Bridge Weight-Limit Posting Practice
1/1/1984
Highway agencies use posted weight-limits to allow continued, limited use of bridges for which the maximum legal load produces stresses in excess of specified levels. This report of the Transportation Research Board contains background information on load-limit posting practices and includes a review of administrative and engineering factors considered in current practice. (Author) [More] | |
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107 - Shallow Foundations for Highway Structures
1/1/1983
This report, which encourages consideration and greater utilization of shallow foundations for highway structures, examines current practices of transportation agencies that make significant use of shallow foundations. Procedures that are not commonly used by transportation agencies but are regarded within the current state-of-the-art of foundation engineering are identified and practices related to bridge foundations are emphasized. Performance criteria for bridge foundations are reviewed in the light of recent studies of performance in relation to foundation movements and compared with criteria for buildings. Case histories are presented to illustrate the potential cost differential between shallow and deep foundations. [More] | |
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106 - Practical Guidelines for Minimizing Tort Liability
1/1/1983
Transportation agencies are subject to increasing numbers of tort suits brought against them for improper performance and alleged deficiencies. The objectives of this synthesis are to familiarize organizations and their employees with this changing situation, make them aware of their duties and responsibilities to the traveling public, and recommend steps that can be taken to mitigate tort liability. Specific recommendations are set forth to minimize tort liability under each of a typical agency's functional areas--managing, planning, designing, constructing, operating, and maintaining facilities. The proposed actions are directed primarily toward public agencies having responsibilities for highway systems. Much of the information presented, however, should also be of interest and value to other groups and functions. The same principles are applicable to all facets of a department of transportation. Much of the material is also pertinent to quasi-public agencies, such as toll highway authorities, and to private companies, such as highway contractors. (Author) [More] | |
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105 - Construction Contract Claims: Causes and Methods of Settlement
1/1/1983
This report identifies the main types of highway construction contract claims and describes their causes and the procedures that currently are used for settling them either through negotiated adjustments under the contract or by reference to various forms of adjudication. Procedures and practices of the state highway agencies and the Federal Highway Administration (FHWA) regarding participation of federal-aid funds in contract claim awards are also discussed. (Author) [More] | |
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104 - Criteria for Use of Asphalt Friction Surfaces
1/1/1983
The most common types of asphalt surfaces used to upgrade frictional characteristics of pavements are seal coats, open-graded mixes, and dense-graded mixes. This report of the Transportation Research Board provides information on current engineering practices, legal and regulatory considerations, and criteria for selection of appropriate types of asphalt friction courses. (Author) [More] | |
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103 - Risk Assessment Processes for Hazardous Materials Transportation
1/1/1983
This document seeks to provide an overview of the use of risk assessment in hazardous materials transport, including hazardous wastes. While it addresses the problem of risk assessment for use in rule making, the document focuses on the needs and means to prevent, reduce, mitigate, and respond to hazardous material transport risks from the perspective of local jurisdictions. Three specific recommendations are made as a result of this study: 1. A study is needed to define the benefits, problems, and costs of using risk analysis criteria for decision making in establishing federal, state, and local rules and regulations for hazardous material transport. 2. A further, formal delineation of the scoping analysis, examples of implementation, and wide dissemination of its application, should be undertaken. In formalizing the scoping analysis, methods must be developed to specify the minimum quantities for consideration. 3. Studies should be undertaken to analytically address the relative risks of intermodal hazardous material transport. (Author) [More] | |
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102 - Material Certification and Material-Certification Effectiveness
1/1/1983
This synthesis will be of interest to materials engineers and others concerned with procedures for assuring the quality of materials used in the construction of highway facilities. Detailed information is presented on various types of certification plans and on the characteristics that determine their degree of success. (Author) [More] | |
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100 - Managing State Highway Finance
1/1/1982
Increased costs for building, repairing and maintaining highways combined with norman deterioration and a decrease in anticipated revenues have placed the transportation system of the United States in jeopardy. The condition of highway pavements in particular has rapidly declined during the past several years. State transportation agencies are coping with fiscal constraints by making more efficient use of existing resources, reducing the scope of transportation services and finding additional or new sources of funding. Good cash flow management is essential. Other financial management strategies likely to be successful are those that (a) address the underlying cause of the fiscal shortfalls, (b) are based on sound analysis of total transportation requirements and options and (c) have the cooperation and support of the decision-making and user groups. [More] | |
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99 - Resurfacing with Portland Cement Concrete
1/1/1982
"This synthesis is concerned with the resurfacing of existing portland cement concrete (rigid) and bituminous cement concrete (flexible) pavements with portland cement concrete (hereinafter referred to as "" concrete""). Concrete resurfacings have been used for one or more of the following purposes: (a) to restore the rideability of the existing pavement, (b) to provide an appropriate surface texture to the existing pavement, or (c) to restore or increase the load-carrying capacity of life or both of the existing pavement. The term ""resurfacing"" is considered inclusive of all these purposes and is used throughout this synthesis instead of the frequently used term ""overlay."" This report deals primarily with highway experience, but city street, county road, and airfield experience have been included where it has been considered to be appropriate. (Author)" [More] | |
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98 - Resealing Joints and Cracks in Rigid and Flexible Pavements
1/1/1982
"The purpose of this synthesis is: 1. To identify the various materials and techniques used to reseal joints and cracks in rigid pavements and cracks in flexible pavements; 2. To determine the costs associated with the use of these materials and techniques; 3. To determine changes in pavement performance resulting from resealing joints and cracks; and 4. To develop criteria for resealing joints and cracks if this practice is found to be beneficial. The scope of this report is limited to the sealing of individual cracks and joints; such area-wide crack sealing techniques as surface treatments, slurry seals, or squeegee-type applications are not described. However, it should be noted that slurry- seal material is used, in some cases, to seal individual cracks and as such is discussed in this synthesis. (Author)" [More] | |
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97 - Transit Ownership/Operation Options for Small Urban and Rural Areas
1/1/1982
"An important choice facing transit decision makers in small urban and rural areas is the type of arrangement to be used for ownership and operation of the system. This report of the Transportation Research Board reviews the choices generally available and evaluates the advantages and disadvantages of each. A framework for the selection of the options is also presented, and the need for more information on the effectiveness of various ownership/operation options is identified. ( Author)" [More] | |
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96 - Pavement Subsurface Drainage Systems
1/1/1982
This report reviews the basic principles and concepts of hydraulic flow that need to be considered in the design, construction, and maintenance of pavements. The need for drainage is noted and the sources and movement of water in the pavement are described. The analysis of basic information on highway geometrics, surface drainage systems, nonpavement subsurface drainage systems, climatology, and soil properties is discussed. The design of subsurface drainage (design criteria, removal of free water, filters), the rehabilitation of existing pavements (by longitudinal subdrains), and current installations (new pavements, edge drains) are also described. [More] | |
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95 - Statewide Transportation Planning
1/1/1982
"A new framework for managing statewide transportation planning is suggested here. The framework consists of two parts: technical (or substantive) and management. The framework recognizes that the day-to- day work of policy planning, communication, programming, and monitoring is a form of planning. The two parts are not independent--management cannot function without the technical content because the ""what"" and "" how"" of transportation affect policies and programs; technicians must be attuned to needs of decision makers and to financial realities. The management side of statewide transportation planning is the area in which some of the greatest changes and improvements have been made in recent years. The synthesis presents examples of good practice by various agencies in strategic planning, estimating financial resources, regulation, communications, productivity, energy, and environment. On the substantive (or technical) side, there are no strong trends or new techniques. The synthesis gives examples of good practice for planning highways, intercity and rural buses, railroads, freight, waterways and ports, aviation, and pipelines. Recent statewide transportation plans are giving more attention to financial policy, communications, and project scheduling; two examples of good statewide transportation plans are presented here. (Author)" [More] | |
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94 - Photologging
1/1/1982
"Equipment and techniques used in photologging (taking photographs of a highway and its environment and, at the same time, recording specific data about the highway) are described. Photologging is used in highway safety studies, studies of traffic control devices, legal studies, and in studies for determinign the location and type of existing guardrails and inspecting potential detour routes. This study concluded that photologging can be used by all organizational units within a state highway agency and has significant application for traffic engineering, design and planning personnel. The factors that affect the degree of use are (a) level of management support, (b) location of the equipment with a unit not identified with any one specific function, (c) and the availability of a complete, updated photolog of an entire highway system. Problem areas relating to equipment, communications, computerized inventories, film costs, and dimensions from photologs were identified. Research needs were also identified." [More] | |
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93 - Coordination of Transportation System Management and Land Use Management
1/1/1982
"This report reviews current practice in coordinating transportation system management (TSM) and land use management (LUM), with emphasis on the ""operating environment"" level as opposed to individual projects. A review of relevant literature was supplemented with interviews with those involved in this field. It is hoped that this synthesis will help identify the research needed for improvements in TSM programs and practices and focus more attention on value of coordinating TSM and LUM." [More] | |
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92 - Minimizing Reflection Cracking of Pavement Overlays
1/1/1982
"Reflection cracks are fractures in a pavement overlay that are the result of, and reflect, the crack of joint pattern in the underlying layer. Reflections cracks can cause early deterioration of an overlay, thereby increasing maintenance costs and decreasing the useful life of the overlay. Methods to minimize reflection cracking of asphalt concrete overlays include (a) greater thickness of overlay, (b) changes in the viscosity of the asphalt, (c) additives incorporated into the asphalt concrete mix, (d) treatments to the existing pavement before overlaying and (e) incorporating stress relieving layers. The results of the various tests using these methods are presented." [More] | |
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91 - Highway Accident Analysis Systems
1/1/1982
"There is a pressing need among state and local highway agencies to develop better highway accident analysis systems. This report is intended to expand on NCHRP Synthesis 21, which is a detailed summary of the types and uses of highway location reference methods. The total highway accident analysis system is discussed here, including the storing, maintaining, retrieving, and analysis of information related to highway locations. This report focuses on the use of data files to ( a) identify high accident locations and features, (b) produce desired accident summaries, (c) process information for countermeasure selection, and (d) evaluate the effectiveness of countermeasures. The use of data systems by police agencies and for research purposes is also discussed. The required resources and the impediments to data processing and analysis are addressed, based on information supplied by state and local highway agencies. Finally, recommendations for improving highway accident analysis systems are provided. (Author)" [More] | |
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90 - New-Product Evaluation Procedures
1/1/1982
"The construction, maintenance and operation of highways and other transportation facilities require the use of great numbers of manufactured products, large quantities of materials and frequent application of specialized processes. Many new products are proposed for use to highway and transportation agencies each year and each item must be evaluated thoroughly before acceptance to provide assurance that the product will fill a need, be cost-effective and not be likely to produce undesirable side effects. New product evaluation is a full time activity and appears to offer the best opportunity for control and standardization in the evaluation process. However, little information is currently available on the benefits being derived from new product evaluations. The regular exchange of information on new products among states and on a national basis is recommended as being valuable for locating useful products and avoiding unnecessary duplication of the evaluation effort." [More] | |
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89 - Geotechnical Instrumentation for Monitoring Field Performance
1/1/1982
"Geotechnical instrumentation for monitoring field performance rather than for investigating and determining in situ properties for design is examined in this synthesis. Field performance monitoring commonly includes measurement of pore pressure, earth pressure, deformation, load, and strain. This report addresses key issues that need to be considered when planning and implementing an instrumentation program. The purpose is to provide guidance that will lead to improved cost effectiveness of instrumentation programs. (Author)" [More] | |
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88 - Underwater Inspection and Repair of Bridge Substructures
1/1/1981
"This synthesis is intended to be of use to bridge maintenance engineers and others concerned with the inspection and repair of bridge elements below the waterline. Problems with substructures are identified, and procedures, equipment, and techniques currently used for underwater inspection are evaluated. The methods and materials used for maintenance and repair of bridge substructures below the waterline are also described." [More] | |
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87 - Highway Noise Barriers
1/1/1981
This summary of progress on highway noise barriers gives quantitative and qualitative perspectives of the design, construction, maintenance, and impacts of the barriers that have been built to mitigate excessive highway noise. The Federal Highway Administration (FHWA) design noise levels are the principal criterion used to determine height and length of a barrier. Most states will not install a barrier unless it will result in a noise reduction of at least 10 dBA (some use 5 dBA as a minimum). Most states use the FHWA model for highway noise prediction, and two thirds of the states design for the most critical receptor. Systematic procedures to obtain data on impacts on residents and motorists are discussed. The perceived effectiveness is often influenced by aesthetics and landscaping of a barrier rather than by acoustical performance. Maintenance problems of barriers include difficulty with mowing close to barriers, litter accumulation, graffiti, and vandalism. Several states have developed priority rating systems for installing noise barriers on existing highways. Design details as well as construction and maintenance aspects are covered in this report. It is recommended that states seek innovative ways to reduce mass of barriers while maintaining noise reduction capability." [More] | |
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86 - Effects of Traffic-Induced Vibrations on Bridge Deck Repairs
1/1/1981
As the number of bridges requiring rehabilitation increases, engineers are faced more frequently with the decision on whether to close a bridge to traffic while repairs are carried out. Most agencies maintain traffic on a deck during construction of a concrete overlay or widening, although several impose speed and weight restrictions on vehicles. Vehicles cause bridges to vibrate which in turn can be detrimental to fresh concrete repairs and overlays thereby increasing maintenance costs. Although overlays appear vulnerable to cracking and debonding under the action of traffic induced vibrations, none of the identified defects has been found to be attributable to traffic on the deck at the time of construction. [More] | |
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85 - Energy Involved in Construction Materials and Procedures
1/1/1981
This report reviews various published energy requirements for highway construction and maintenance, including the energy requirements for processing the materials and the fuel used in hauling and for construction equipment. The emphasis here is that decisions concerning the use of alternative types of materials for highway construction and maintenance should be based on technological considerations, safety and the cost effectiveness of alternatives rather than on uncertain estimates of energy requirements. It is important to realize that energy computations include separate determinations for construction, transport, processing and calorific energy and that the relative amounts for different processes and materials be given consideration in any decisions concerning the use of alternatives. [More] | |
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84 - Evaluation Criteria and Priority Setting for State Highway Programs
1/1/1981
"The purpose of this synthesis is to report on how state departments of highways and transportation currently make decisions on the allocation of available funds to highway programs and projects. There are four factors which must be used in combination to satisfy the need to distribute limited funds equitably: 1. Strategic planning involves the responsible state agency in the implementation of a systematic management and technical process for making decisions on how to spend the limited funds available. 2. Technical factors, including the use of data and technical procedures, should be employed to assist in the selection of priorities. 3. Intangible factors, such as legislative mandates, emergency projects, and special emphasis programs, must be weighed and considered in the overall process, and 4. Political factors, which can also be considered intangibles, must not be overlooked especially when new, big, and expensive projects need legislative action and approval." [More] | |
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83 - Bus Transit Accessibility for the Handicapped in Urban Areas
1/1/1981
Many transit systems provide accessible, fixed-route service for handicapped people, which means that buses on regular routes are equipped with lifts that enable a person in a wheelchair to board the bus. This synthesis is intended to assist transit systems in implementing such services in conformity with state or federal requirements or in response to goals and objectives of individual communities. The physical, technical and operational characteristics of lifts and buses are discussed. In addition, consideration is given to the climate and terrain and to the ease of access to stops for both user and bus on accessible services, reliability and maintenance of lifts, and scheduling delays due to wheelchair boardings. The level of accessible service provided, the operational procedures chosen, and the maintenance experiences and policies affect one another. They also affect ridership by the handicapped and nonhandicapped. Handicapped ridership on most routes with lift-equipped buses has been low, but some of the factors affecting ridership are changing. As service becomes more widespread, reliable and frequent, ridership may increase. The report also discusses cost-effectiveness of accessible transit services and the alternatives, and problems in obtaining accurate cost and ridership data. Lift-equipped, fixed-route transit service addresses the needs of only a small number of handicapped travelers, principally wheelchair users. It does not meet the problems of many other handicapped travelers--such as information needs (before and during travel), difficulties waiting at stops or standing in a moving vehicle, difficulty in paying fares, and mental disorientation. There are measures which would remedy these and other problems. However, it is not known what the costs are or how many travelers would be aided. [More] | |
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82 - Criteria for Evaluation of Truck Weight Enforcement Programs
1/1/1981
"The purpose of a truck weighing program is to enforce legal load limits and thus prevent trucks from damaging highways and bridges. Essential to truck weight enforcement is the effective combination and deployment of the various types of scales (permanent, portable and semiportable). Each state needs to evaluate its truck weight enforcement program, beginning with cooperation within and among agencies involved. Each state needs to determine the most effective enforcement procedures possible under the law in light of the existing facilities and available personnel and with minimal expenditures for additional facilities and equipment. Long range goals are also necessary along with methods for measuring the effectiveness of truck weight enforcement programs. Weight law enforcement is similar to speed enforcement: violators will be deterred as long as enforcement is consistent and effective." [More] | |
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81 - Experiences in Transportation System Management
1/1/1981
"This report summarizes experiences with more than 150 Transportation System Management (TSM) actions and provides guidelines within the context of nine operating environments, namely, freeway corridor, arterial corridor, central business district, regional operating environment, neighborhood, major employment site (non CBD), outlying commercial center, major activity center, and modal transfer point. The characteristics, TSM options, motivation for action, goals and objectives, implementation experiences, and guidelines are described for each of the above environments. The successful TSM experiences were found to have the following characteristics: strong, innovative person; coordinated teamwork; an identifiable problem; adequate planning analysis to determine system impacts; and proper packaging of TSM strategies and support measures." [More] | |
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80 - Formulating and Justifying Highway Maintenance Budgets
1/1/1981
"There are three basic types of highway maintenance budgets in general use: line-item, lump-sum and program/performance. Line-item maintenance budgets are established on the basis of money instead of work to be accomplished. Lump-sum budget funds are appropriated in one lump-sum for maintenance purposes. A program budget is based on work programs which are subdivided into activities such a crack sealing or pothole patching. Justification of the maintenance budgets is based on the importance of the highway network, the demands of users and abutting property owners and the consequences of insufficient maintenance. Also needed is the development of budget tools to relate maintenance expenditures to long-term benefits, cost effective maintenance strategies and objective procedures to establish priorities among maintenance deficiencies." [More] | |
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79 - Contract Time Determination
1/1/1981
"Transportation agencies must set reasonable times for completion of construction projects. Factors to be considered in determining contract time include materials, equipment, manpower, cost, and constraints such as weather, regulations, traffic, utilities, and user convenience. This report of the Transportation Research Board presents guidelines and recommendations for the establishment and enforcement of contract times. To develop this synthesis in a comprehensive manner and to ensure inclusion of significant knowledge, the Board analyzed available information assembled from numerous sources, including a large number of state highway and transportation departments. A topic panel of experts in the subject area was established to guide the researcher in organizing and evaluating the collected data, and to review the final synthesis report. The conclusions reached in this synthesis include the following: When establishing or modifying a time- estimation procedure, the performance of the procedure should be monitored, the effects of site conditions and terrain should be considered, and information should be obtained from state contractor associations. In determining contract time, a construction data file that covers the previous 3 to 5 yr should be used. The schedule should be reviewed and adjusted to reflect other factors, such as project size, availability of materials, and commitments of the agency engineering and inspection forces. Except for certain projects that must be completed within narrow time limits, there does not appear to be a need for highly restrictive contract duration times. The working- day and calendar-day methods have an advantage over the completion-date method in that the contractor is not liable for circumstances beyond his control; however, the agency must be careful to document each day that is charged. Suggested guidelines include: Agencies should be flexible in establishing contract time. Construction season time limits have merit for some work, particularly for paving and resurfacing projects. Once specified, contract time becomes a contractual condition and should be enforced. Time charges on working- day contracts should be administered uniformly and fairly. It appears desirable and equitable to prescribe liquidated damages for (a) the time that traffic and the public are inconvenienced and (b) supervision costs incurred by the agency. A formal, rational approach should be developed to determine contract time; it should be based on past experience and updated frequently. (Author)-" [More] | |
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78 - Value Engineering in Preconstruction and Construction
1/1/1981
"The results of value engineering (VE) applications to preconstruction and construction operations in eight states and the experiences of the U.S. Army Corps of Engineers are reviewed. The results indicate that the application of VE concepts, principles and techniques is effective enough to warrant increased use by state highway and transportation agencies. Best opportunities for initial application appear to exist in preconstruction, with emphasis on application to standard plans and specifications and on design criteria and guidelines. Data also indicate that savings from the implementation of a value engineering incentive clause (VEIC) program for contractors can be significant. Also VEIC programs can be expected to field ongoing benefits for a one- time sharing. This study found that problems in implementing and managing VE programs are more behavioral and organizational than technical. Top management support and middle management understanding and support are essential to the success of a VE program. This synthesis presents guidelines in preconstruction which relate to project selection, timing, participation, standard plans and specifications and design criteria, and the team approach. Guidelines for VEIC programs are presented which focus on the VEIC clause, contractor participation, opportunities for participation, objective appraisal, and the expeditious processing of change proposals. [More] | |
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77 - Evaluation of Pavement Maintenance Strategies
1/1/1981
"Performance of a pavement is greatly affected by the type, timeliness and quality of maintenance it receives. Regular maintenance can slow the rate at which a pavement deteriorates from traffic loads and climatic conditions. Nationally, pavements are deteriorating faster than they are being restored because maintenance funds have not been sufficient to take care of the needs. Pavement maintenance strategies are closely related to and a component of pavement management systems. Pavement management in a broad sense includes all the activities contained in the planning, design, construction, and rehabilitation of a pavement. Recommendations for pavement maintenance include: selection of alternative treatments should consider present serviceability of the pavement, probable performance of alternative treatments, required life of pavement, costs, effects on traffic flow, effects on road user, appearance and availability of resources; each agency should have a maintenance manual that covers major pavement defects, alternative strategies, cost and life of each strategy, and a pavement management system is desirable for effective development of pavement maintenance strategies." [More] | |
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76 - Collection and Use of Pavement Condition Data
1/1/1981
"Pavement condition data are collected and used to establish maintenance and rehabilitation priorities, to select maintenance and rehabilitation strategies, and to project pavement performance. The pavement condition data is grouped as follows: roughness (ride), surface distress, structural evaluation (deflection), and skid resistance. The equipment used to measure roughness includes the CHLOE profilometer, car ride meter, and loser profilometer. Most agencies used a car ride meter. Advantages and disadvantages of the latter are noted. Surface distress ( a measure of pavement fracture, distortion, and disintegration) information is obtained by surveying and recording various defects such as cracking and rutting. Survey methods are usually subjective and variation in data can be minimized by having rates stop at the same location each year, obtaining data every 1 or 0.5 mi, obtaining a consensus of at least two raters for each segment, and keeping procedures as simple as possible. Structural adequacy is measured, by surface deflection measurements (Static deflection, steady - state dynamic deflection, impact - load response). Skid resistance data are routinely collected by most agencies by locked-wheel or yaw-mode trailers. The amount of pavement network on which data are collected varies among the agencies. Problem areas encountered during data collection and analysis are noted." [More] | |
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75 - Transit Boards-Composition, Roles, and Procedures
1/1/1981
This Synthesis presents current practices relating to the composition and role of transit boards and suggests features of organization and interrelationships that may affect the activities of the board. These features include the intergovernmental relationships of the transit authorities (as special-purpose governments) with the general-purpose governments in the area, and the intergovernmental relationships of the board (as a citizen-oriented body) with the technical management personnel of the transit authority. Transit board members are usually appointed from the public by elected officials. The transit agencies also usually have a manager and/or executive director. The roles of both the board and the manager must be well defined to avoid conflicts. Agencies have suggested that the board should not be involved in daily problems of operating the system. It should also be taken into consideration that policies and planning are influenced by those with daily contact with the riding public, and that the complexity of bus operation and maintenance and the dependence on federal and state grants demand considerable technical knowledge of system operations. Many agencies use some form of contract management for operation of bus or paratransit systems. Ths relieves the agency of labor negotiations. The study also showed that (a) there is a need for reliable funding sources, (b) there are both advantages and disadvantages to each type of organizational structure, and (c) there are various methods for selecting board members. [More] | |
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74 - State Transit-Management Assistance to Local Communities
1/1/1980
Because communities were unable to take advantage of federal financial aid for transit, states provided part or all of the matching funds required to obtain federal aid. Some states, in addition, also aided local communities. Another major problem is the lack of skilled management staff. Many state governments are in a position to give needed management assistance to public transportation systems in preparing grant applications, aiding with documentation, determining appropriate federal officials to contact for advice, and providing examples of successful grant applications. The state can establish an information clearinghouse to share information about federal programs, maintenance techniques, labor agreements, and other relevant items. Other areas of possible state assistance include management performance audits, handbooks, personnel recruitment and training, equipment selection and purchase, insurance, and marketing. A strong state management and technical assistance program bill contribute to improved local transit and enable the achievement of state transit goals and objectives. This report discusses the Urban Mass Transportation Act of 1964, various types of state financial aid programs, and management assistance (goals, needs of local transit, the state role, state assistance programs, and tables of state programs). [More] | |
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73 - Alternative Work Schedules: Impacts on Transportation
1/1/1980
"This synthesis presents information on implementation of staggered and flexible work hours and compressed workweeks and on the impacts of such measures on highways, transit systems, and ride-sharing programs. Alternative work schedules can be used to manage transportation demand by shifting commuters away from the peak hours and by reducing the number of days that people need to travel to work. Evaluations of large- scale variable work hours programs show that peak-hour bus loads and automobile arrivals at parking garages decrease 10 to 20 percent, and peak-hour automobile traffic volumes on major approaches to work centers are reduced by 5 to 10 percent. Staggered and flexible work hours result in reduced travel times, reduced load factors, and thus less crowding on transit and less waiting time for elevators in buildings. It appears that flexible hours programs have a positive effect on transit and carpool use. Theoretical analyses indicate that compressed workweeks can significantly reduce peak-period work trips and congestion although there may be negative effects on carpooling and transit ridership. Implementation of an alternative work schedule program begins with the determination that there is a congestion problem that could be alleviated by shifting transportation demand to less congested periods. After commitments are obtained from public and private organizations, a lead agency should be established, preferably the same one that is coordinating ridesharing. The following implementation steps are suggested: (a) high-priority employment locations; (b) obtain support for feasibility studies; (c) conduct work schedule and transportation surveys of employers; design work rescheduling plans; (e) obtain management decisions to implement; (f) provide implementation assistance; (g) evaluate impacts; and (h) refine and extend the program." [More] | |
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72 - Transportation Needs Study and Financial Constraints
1/1/1980
"High inflation rates have caused costs for contruction, maintenance, and operation of transportation facilities to increase more rapidly than revenues. To operate within available funding limits, many states have been forced to reduce the magnitude of programs and levels of service. This report of the Transportation Research Board focuses on use of needs studies as a basis for developing programs within constrained financial resources. Guidance and procedures are provided for the following aspects of transportation needs studies and financial constraints: (a) techniques for estimating needs; (b) criteria for developing program packages; (c) considerations in making tradeoffs among geographical, modal, political, and other options; (d) techniques for documenting funding deficiencies to increase awareness of the public and political decision makers; (e) identification of potential sources of additional revenue; and (f) methods of ""downscoping"" proposed projects. (Author)" [More] | |
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71 - Direction Finding from Arterials to Destinations
1/1/1980
"Highway agencies have developed various procedures to assist motorists in finding the way from arterial highways to destinations in unfamiliar areas. This report of the Transportation Research Board documents the range of technical, legal, political, social, and environmental factors affecting the development of information systems designed to meet drivers' direction-finding information needs. To develop this synthesis in a comprehensive manner and to ensure inclusion of significant knowledge, the Board analyzed available information assembled from numerous sources, including a large number of state highway and transportation departments. A topic panel of experts in the subject area was established to guide the researchers in organizing and evaluating the collected data, and to review the final synthesis report." [More] | |
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70 - Design of Sedimentation Basins
1/1/1980
"Sedimentation basins are useful for minimizing the effects of highway construction runoff on the environment and are often used in conjunction with other sediment-control practices. A sedimentation basin protects streams, lakes, recreation areas, and other areas that cannot tolerate sediment deposition. There are three types of sedimentation basins--expedient, temporary, and permanent. Expedient basins are quite small, exist for only a short time (possibly only one night), and their sites are determined by the engineer during grading operations. Temporary basins remain in place for the entire duration of a construction project or until the need for them clearly has passed. Their locations are usually shown on the plans, and they are built to a higher standard than expedient basins. Permanent basins are used to intercept sediment during construction but remain after construction for other uses such as recreation, scenic enhancement, floodwater detention, or groundwater recharge. There are two design philosophies for sedimentation basins. According to one, a basin shall not discharge during small, frequent runoffs but shall be allowed to discharge during major storms. These basins are designed to trap all sediment (except from major storms) and are cleaned out often, probably after each storm. Adherents to the second philosophy hold that a basin operates as a detention reservoir while sediment is deposited by flow moving slowly through. Calculation of basin size requires information about the drainage area that includes erosion characteristics, surface cover and condition, and length and steepness of slopes. For the flow- detention philosophy, the designer will also need to estimate the sediment volume to be stored (using a rule of thumb or the universal soil loss equation), determine the percentage of eroded volume that will reach the basin, and estimate the efficiency of the basin in trapping sediment. Then the height of the dam can be calculated and the principal and emergency spillways can be designed. (Author)" [More] | |
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68 - Motor Vehicle Size and Weight Regulations, Enforcement, and Permit Operations
1/1/1980
"Many of the problems associated with enforcing oversize and overweight limits derive from the confusing variety of requirements--for applications, fees, issuance, signs, flags, escorts, actual limits, fines--from state to state and within states. This lack of uniformity sometimes leads truckers to believe that it is cheaper and less time consuming to risk being caught than to conform to law. The report strongly recommends that uniform standards for interstate overlimit travel be sought. Enforcement efforts and permit procedures also need to be coordinated. (Author)" [More] | |
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67 - Bridge Drainage Systems
1/1/1980
"Design principles and procedures and maintenance practices for bridge drainage systems are evaluated in this report, which also includes recommendations for improvements on current practice. Bridges should have adequate cross-slope and grade to allow the water to run quickly into drains. Where grades permit, some states carry all the water to catch basins at the ends. An inlet box may be used to collect the runoff. Some states have detailed procedures for determining drain spacing. Debris can be controlled by keeping it out of inlet boxes, accepting and storing it so it cannot go through the system, or transporting it through. Maintenance at regular intervals is the key to the success of a drainage system. Disposal of run off water can be a simple straight drop onto the land or water beneath the bridge or a pipe system to carry the water to the local sewer system. Current practices indicate that deck cross-slope and grade should be less than 2% and 0.5% respectively; that bridge drains may be holes through the deck, fabricated inlet boxes, or catch basins at the ends of the bridge; that inlet areas should be as large as possible; that pipes should have a minimum diameter of 6 in., a miminum radius of 18 in., and a minimum slope of 2%; that cleanout plugs and elbows should be easily accessible; that there should be improved communication between designers and maintenance personnel; and most importantly, that bridge drainage systems should be regularly and carefully inspected and serviced." [More] | |
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66 - Glare Screen Guidelines
1/1/1979
"This synthesis will be of interest to design engineers and others seeking information on the use of glare screen to shield drivers' eyes from the headlights of oncoming vehicles. Information is presented on various types of glare screen and the parameters involved in their design. Glare can be avoided through highway design (wide medians, separate alignment, earth mounds), barriers, plantings, fencing, or glare screen on median barriers. Glare screen may be continuous partition (either opaque or with intermittent openings or a series of objects of such width and spacing as to block out glare. Design parameters for glare screen include median width, barrier type, vertical curvature, and horizontal curvature. Among the conclusions of the synthesis are: accepted cutoff angle for glare screens is 20 degrees plus the degree of curvature; more effort is needed to simplify glare screen hardware for easier maintenance, development of an accident warrant is not likely; veiling brightness should be studied to see if it can be used as a warrant for glare screen; and geometric design standards should be reviewed in relation to use of glare screens in median." [More] | |
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65 - Quality Assurance
1/1/1979
"This synthesis will be of special interest and usefulness to construction engineers, materials technologists, and others concerned with control and assurance of quality in highway construction. Detailed information is presented on quality assurance philosophies, programs, practices, and procedures. Administrators, engineers, and researchers are faced continually with many highway problems on which much information already exists either in documented form or in terms of undocumented experience and practice. Unfortunately, this information often is fragmented, scattered, and unevaluated. As a consequence, full information often is fragmented, scattered, and unevaluated. As a consequence, full information on what has been learned about a problem frequently is not assembled in seeking a solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem. In an effort to correct this situation, a continuing NCHRP project, carried out by the Transportation Research Board as the research agency, has the objective of synthesizing and reporting on common highway problems. Syntheses from this endeavor consitute an NCHRP report series that collects and assembles the various forms of information into single concise documents pertaining to specific highway problems or sets of closely related problems. Many factors influence the performance of highways and bridges. This report of the Transportation Research Board reviews these factors and outlines the major components of quality assurance systems used by state highway agencies to ensure compliance with specifications. A number of states have reported favorable experience in basing their testing and inspection procedures on end- result or performance type specifications. Use of statistical probabilities in quality control and assurance programs is also discussed in this report. To develop this synthesis in a comprehensive manner and to ensure inclusion of significant knowledge, the Board analyzed available information assembled from numerous sources, including a large number of state highway and transportation departments. A topic panel of experts in the subject area was established to guide the researchers in organizing and evaluating the collected data, and to review the final synthesis report. This synthesis is an immediately useful document that records practices that were acceptable within the limitations of the knowledge available at the time of its preparation. As the processes of advancement continue, new knowledge can be expected to be added to that now at hand. /Author/" [More] | |
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64 - Bituminous Patching Mixtures
1/1/1979
"Bituminous patching mixtures are combinations of bituminous binders and aggregates that have special characteristics needed for filling holes in pavements. The different types of patching mixtures can be placed in one of three groups: hot-mixed, hot-laid; hot-mixed, cold-laid; and cold-mixed, cold-laid. Among the properties that a bituminous patching mixture should have are: stability, to allow the patch to resist displacement by traffic; stickiness, so the patch will stick to the sides of the hole; resistance to water action, to keep the binder from stripping of the aggregate; durability, so the patch does not ravel or crack; skid resistance as good as the pavement in which it is placed; workability, to enable the material to be easily shoveled, raked, and shaped; and storageability, so the mixture can be stockpiled without hardening excessively or having the binder drain off the aggregate. Various tests are used for specifying, designing, and approving patching mixtures. Stability tests are rarely used and then only to control hot-laid mixtures. Adhesion tests are used more often. These include coating tests, stripping tests, or an immersion-compression tests (only for hot-laid mixtures). Design of hot-laid patching mixtures is essentially the same as for dense-graded, hot-mixed asphalt concrete. For cold-laid mixtures, there is no widely adopted formal design process; however, successful procedures, usually involving trial- and-error, have evolved over time. Production methods for patching mixtures are essentially the same as for other bitumionus mixtures. The hot-laid materials are used immediately, and cold-laid mixtures are stored for use as needed. In recent years, composite bituminous mixtures have been developed. These include sulfur-asphalt mixtures, addition of portland cement, and reinforcement with polyester fibers, rubber, or inorganic fibers. However, there is only limited field experience with these composites." [More] | |
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63 - Design and Use of Highway Shoulders
1/1/1979
"Data for this synthesis was acquired from a questionnaire received from forty-three states in 1977. It was divided into sections on policy and procedures, design, and operations. In the area of policy and procedures, the predominant criterion used by the states to select the shoulder type, thickness, width, and slope is the combination of highway classification and traffic volume. Most of the states depend on the cross slope of the shoulders for surface drainage, but a significant number of states use some form of dikes, catch basins, or gutters. For subsurface drainage, the predominant policy is to use underdrains or a free-draining base. In the design area, most states use the same width and slope of shoulders adjacent to both rigid and flexible pavements. On freeways, nearly 80 percent of the states use a 10-ft (3-m) width for the outside shoulder. The predominant shoulder slope is 4 percent or 1/2 in. per foot. Most of the states pave the shoulders on the Interstate and major highways, but on local roads the shoulder material is often some form of aggregate, earth, or sod. In the area of operations, only five states permit regular use of shoulders for slow-moving vehicles, although 10 states permit such use under certain conditions. Shoulder maintenance is not performed on a regular schedule in most states; even in those states that have a schedule, it frequently applies only to unpaved shoulders. Little data were received on maintenance costs. Some of the recommendations of this synthesis include research into the safety effects of shoulders, particularly with respect to the types in use; evaluation of the effects of shoulder types on pavement performance; a study of maintenance costs of various types and designs of shoulders; and more definitive construction costs to enable better selection of shoulder types for given conditions." [More] | |
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62 - State Resources for Financing Transportation Programs
1/1/1979
"In recent years, the states have faced a crisis in the provision of transportation facilities and services. Some of the reasons for this crisis are: A revenue base that is not responsive to inflation; A relative slowdown in motor fuel consumption, the principal present source of revenue; Soaring costs; Greater sensitivity to social and political pressures; and Increasing demands for transportation facilities and services. Improvements in motor vehicle fuel efficiency and conversion to new energy sources will worsen the situation. One of the strengths of current transportation financing--the dedication of highway funds--has contributed to the difficulties many states are facing. Dedication has tended to isolate highway financing from the mainstream of policy making, shielding it from the attention of legislative bodies and preventing revenue problems from receiving early deliberation and action. User charges are employed widely by the states to defray highway costs. In recent years, this financing system has fallen prey to inflation, and states have looked more eagerly to other revenue sources. The discussion here identifies these potential revenues and their relative merits and demerits. The criteria for appraising the quality of a tax structure include: Equitable distribution of the burden, Minimal interference with economic decisions in otherwise efficient markets, and Efficient and nonarbitrary administration. A diverse state and local tax structure tends to minimize tax competition between jurisdictions. A combination of financing may be preferable to reliance completely on either general tax subsidy or total benefit financing. A judicious combination of the two methods might promote equity and minimize excess burden. An in- depth review of both user financing and general taxation has turned up no hidden revenue fountain to rescue states from difficulties in providing for transportation needs. On the positive side, no flaws were revealed in current methods of financing of such nature and magnitude that appropriate revenue levels cannot be achieved. Revenue issues pertain mainly to the distribution of the burden. What appears to be needed is an institutional framework that will facilitate timely adjustments in the revenue structure. The many issues involved in transportation financing are complex, and much pertinent information gathered for this synthesis could not be included. The material not included has been published by the University of California (l), and readers desiring a more detailed discussion of this subject are referred thereto." [More] | |
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61 - Changeable Message Signs
1/1/1979
"Changeable message signs are being used increasingly to reduce congestion and prevent accidents in both rural and urban locations. Because of the rapid development of improved technology, there is a need for up-to-date information on the characteristics, applications, and effectiveness of changeable message signs. This report of the Transportation Research Board includes information on requirements for design, installation, operation, and message effectiveness. It also contains a review of previous and current research, and future development needs are identified. /Author/" [More] | |
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60 - Failure and Repair of Continuously Reinforced Concrete Pavement
1/1/1979
"The performance of CRCP has revealed a number of failure modes that are traceable to design, construction, materials, and maintenance deficiencies and such other factors as environemntal conditions and traffic loadings. This report of the Transportation Research Board includes a review of the cumulative experiences of state that have constructed and maintained CRCP. Guidelines for repair techniques are included, and areas of needed research are identified. /Author/" [More] | |
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59 - Relationship of Asphalt Cement Properties to Pavement Durability
1/1/1979
"In recent years, apparent changes have evolved in the physical properties of asphalt cements used in pavement construction. Some of these properties are not controlled or are controlled only partially by AASHTO specifications. This report of the Transportation Research Board reviews all available information relating durability and performance of asphaltic concrete mixtures to the properties of the asphalt cement. Recommendations for improved test procedures and criteria are included. The report concludes that hardness of the asphalt is the property most important to pavement performance. /Author/" [More] | |
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58 - Consequences of Deferred Maintenance
1/1/1979
"Expenditures for maintenance are not keeping pace with the needs of the nations highways. Desirable maintenance activity is not being carried out, and the backlog of work needed to restore the facility to good condition is growing. Difficult judgments must be made in deciding to defer maintenance. To effectively manage a maintenance program, levels of service must be able to be defined, measured, and evaluated. This report of the Transportation Research Board reviews concepts for quantifying maintenance needs, setting priorities, and developing strategies. Relevant studies in progress are discussed and additional research needs are outlined. /Author/" [More] | |
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56 - Joint-Related Distress in PCC Pavement: Cause, Prevention, and Rehabilitation
1/1/1979
A significant amount of scarce highway maintenance funding is expended each year on rehabilitation of transverse joints in portland cement concrete pavement. This report of the Transportation Research Board reviews the causes of distress and ways in which join problems might be prevented. Rehabilitation methods and techniques for their selection are also discussed. /Author/ [More] | |
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55 - Storage and Retrieval Systems for Highway and Transportation Data
1/1/1978
The increasing complexity of operating highway and transportation departments has caused many agencies develop comprehensive computer systems for storage and retrieval of data. This report of the Transportation Research Board reviews and evaluates what has been accomplished to data and includes recommendations for future development. /Author/ [More] | |
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49 - Open-Graded Friction Courses for Highways
1/1/1978
"Open-graded friction courses have been used increasingly in recent years for pavement surfaces throughout the United States. This report of the Transportation Research Board contains currently available information on mixture design procedures, material selection and evaluation, construction procedures, cost effectiveness, maintenance, safety aspects, and pavement performance. /Author/" [More] | |
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48 - Priority Programming and Project Selection
1/1/1978
"The procedures followed in programming (the matching of available projects with available funds to accomplish the goals of a given project) are outlined. The 15-step basic programming process, derived from a review of published documents and interviews with highway administrators, ranges from project initiation through modification. Several steps (e.g. prioritizing and financial analysis) are described in detail, and a list of definitions for the basic terms used in planning and programming is provided." [More] | |
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47 - Effect of Weather on Highway Construction
1/1/1978
"Materials, equipment, personnel, and the quality and quantity of work can be adversely affected by weather. Delays in project completion and increased costs can also result. This report of the Transportation Research Board reviews measures taken by highway agencies to mitigate the impact of adverse weather conditions. Practices related to a number of specific construction activities are discussed. /Author/" [More] | |
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42 - Design of Pile Foundations
1/1/1977
This report reviews design principles and construction problems associated with pile foundations, and recommends criteria based on current knowlege. The problem of determining whether or not the site conditions are such that piles must be used is discussed, as well as the selection of the pile type. The ultimate load on a pile is the load that can cause failure of either the pile or the soil. The pile failure condition may govern design where pile points penetrate dense sand or rock, but in most situations, ultimate load is determined by the soil failure. The computation of the ultimate load is discussed. For design purposes the ultimate load is separated into two components: the base or point load, and the shaft or skin load. The displacements needed to mobilize skin resistance, the mechanics of load transfer between pile and soil, and the settlement analysis of pile foundations is reviewed. Pile spacing, lateral deflection, slope or pile axis, position and magnitude of maximum bending moment are covered, as well as lateral loading caused by horizontal displacement, buckling, and pile driving. In-situ full-scale pile load tests are also discussed. [More] | |
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40 - Staffing and Management for Social, Economic, and Environmental Impact Assessments
1/1/1977
"This report presents the results of a comprehensive review and assessment of the management acitivites that various transportation agencies - state and local - have undertaken to address environmental concerns. Staff changes, additions, and training are reported. Procedures used to coodinate the input of other state, federal, and local agencies and citizens groups; steps taken to ensure early and continuous citizen input; and ways to ensure an interdisciplinary approach to the preparation of an environmental impact statement are also reported. /Author/" [More] | |
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36 - Instrumentation and Equipment for Testing Highway Materials, Products, and Performance
1/1/1976
"State transportation agencies were contacted and requested to submit information on new or recently added equipment and/or new uses for old or new equipment for laboratory or field testing for quality assurance and control of highway materials. Information was received from 44 agencies. The information received from the transportation agencies is separated into two categories, equipment primarily for laboratory tests and that primarily for field tests. Each category is subdivided into groups by specific equipment or type of test. The data include 312 laboratory items and 152 field items. Costs of individual items of equipment range from $10 to $340,000. Findings are presented in the form of tables containing user agencies' experiences and viewpoints on each item." [More] | |
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33 - Acquisition and Use of Geotechnical Information
1/1/1976
"This report presents the results of a comprehensive review and assessment of the current practices of state highway and transportation agencies in the acquisition and use of geotechnical information in route selection, design, and construction of transportation facilities. Information is presented on such matters as planning, conducting, and presenting information from geotechnical investigations, the equipment, procedures, and selection of sampling locations for geotechnical investigations, and the structuring and positioning within the agency framework of the organization that must acquire and use geotechnical information." [More] | |
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28 - Partial-Lane Pavement Widening
1/1/1975
"Information from many highway departments and agencies was assembled and analysed in this effort to record and evaluate current practices in the use of partial-lane pavement widening. Specific problems on partial-lane pavement widening projects (narrow work areas, acquisition of additional right-of-way, variable subgrade, reconditioning of existing pavement, reflective cracking, structure widening, surface and subsurface drainage, traffic during construction, access for abuting owners, and funding projects) have been addressed and practices have been developmed to meet specific needs. Nearly all partial-lane widening projects include provisions for placing an overlay over both the old and new pavement. In a few cases the overlay may be placed during the following construction season. The modification of the existing surface drainage, alignment improvement (by shifting the widening, where possible, to the inside of curves; replacement of small angles by a smooth curve), minimizing reflection cracks by provision of good subsurface drainage, compaction of widening trench at or near the optimum moisture content, provision of good shoulder support, and the use of substantial overlay to cover the joint) are some practices described. The open trench hazard, and advance coordination with abutting residents and businesses to avoid inconvenience are also discussed. Safety, capacity and maintenance are important factors in planning the widening projects. Long-range and short-range plans, project selection, citizen participation and factors which affect the decision-making process are outlined. The various aspects of design and construction are covered." [More] | |
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23 - Getting Research Findings into Practice
1/1/1974
This report presents the results of a comprehensive review and analysis of existing information on the various procedures that have been employed by highway agencies under a wide variety of organizational structures to translate the results of research into practice. The processes in several instances are subjected to detailed dissection so that the important elements can be easily recognized by those wishing to improve their own implementation practices. Most successful procedures were found to be constructed around the premise that effective implementation is a continuous process that begins at the earliest stage of planning of a research endeavor and remains active until utilization of the product of the endeavor is realized. [More] | |
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21 - Highway Location Reference Methods
1/1/1974
A highway location reference system is a set of office and field procedures that includes a highway location reference method. The latter is a way to identify a specific location with respect to a known point. The system is seen as the procedures that relate all locations to each other and includes techniques for storing, maintaining, and retrieving location information. This report deals mainly with location reference methods, but recognizes that it is difficult to discuss methods apart from the system. The following methods are described: (1) the sign-oriented method (placement of either milepost signs or reference post signs along roadways); (2) the document- oriented methods (used because an agency did not want to incur the costs of installing signs in the field); and (3) other experimental methods, chief among them being the use of coordinates and the use of roadside land marks as reference points. There is not a great deal of difference between the most common methods. Little information on the costs of the various systems is available. The placement of physical markers remains a question. On two-lane highways, placement at alternating sides of the road has been used successfully by several states. On divided highways, a bettwe procedure is the placement on both sides. When two or more routes are concurrent, it is recommended that signs that include a route number contain the number of the highest level on the concurrency. It is also recommended that the public be informed as to the use of the such signing. [More] | |
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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 326: Strategic Planning and Decision Making in State Departments of Transportation examines state and provincial transportation departments' experience with strategic planning and synthesizes current approaches to linking strategic planning with other decision-making processes, including operational and tactical planning, resource allocation, performance management, and performance measurement. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis Report 324: Prefabricated Bridge Elements and Systems to Limit Traffic Disruption During Construction assesses and documents the use of innovative prefabricated elements and systems and assesses its effects on on-site construction time and cost, closure time, and environmental impacts. The synthesis report also looks at the use of fiber-reinforced polymers and other advanced materials and new technologies that are gaining in popularity but are still in the experimental stages.
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis Report 323: Recruiting and Retaining Individuals in State Transportation Agencies examines various state and Canadian province departments of transportation (DOT)employee recruiting and retention strategies, and highlights those practices that might have the greatest potential for success and implementation in other DOTs.
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis Report 322: Safety Management Systems (SMS) provides an overview of current transportation agency practices, recent literature findings, and reviews of two model state SMS initiatives. According to the report, benefits derived from the SMS process are increased coordination, cooperation, and communication among state agencies and improvements to data analysis and collection procedures, as well as collaborative strategic plans.
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 321: Roadway Safety Tools for Local Agencies examines the safety tools and procedures that are practical and relatively easy to apply, and that can be implemented by agencies with limited financial support and personnel. Recognizing the wide variation in the operations and responsibilities of local agencies, the report acknowledges that the level of expertise in transportation safety analysis also varies greatly.
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis Report 320: Integrating Freight Facilities and Operations with Community Goals identifies practices that have been or are being used by private-sector freight companies and public transportation agencies in citing their facilities, modifying their operations, and managing their community relations. “Good neighbor initiatives” and balancing practices employed by metropolitan planning and economic development organizations, local governments, and others are also recognized. The report covers water, truck, rail, and air freight facilities and operations. Although the report does not include pipelines, several of the issues and practices discussed are relevant to pipeline facilities and operations.
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 319: Bridge Deck Joint Performance presents the state of the practice on commonly used expansion joint systems in bridges by summarizing performance data for each system type and by providing examples of selection criteria and design guidelines. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 318: Safe and Quick Clearance of Traffic Incidents profiles laws, policies, and procedures for facilitating clearance of traffic incidents, primarily those initially blocking travel lanes and attended to by the vehicle operator, on highways in urban and rural areas. The report discusses quick clearance legislation, hold harmless laws, policies governing the removal of accident victims, the duties of private tow companies, and more.
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 317: Dealing with Truck Parking Demands identifies successful and innovative strategies that have been implemented by transportation agencies, as well as potential strategies yet to be deployed in order to meet the increasing demand for truck parking. The report examines the legislative authority governing the provision of truck parking by state transportation agencies, including federal requirements and selected state laws. An analysis is provided of the demand for truck parking. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 316: Design Exception Practices describes the range of design exception practices among state transportation agencies, and discusses problems and suggested improvements based on the experience of state agency personnel. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 315: Compensation for Contractors' Home Office Overhead examines the approaches used by state departments of transportation to compensate contractors for unabsorbed home office overhead for contract delays and contractor's perceptions of these approaches. In addition, the issues of how the federal government and the private sector address home office overhead, and what case law and regulations can be involved are discussed. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 314: Strategies for Managing Increasing Truck Traffic documents recent efforts by transportation organizations that construct, operate, and manage the transportation system and identifies truck-related challenges, planning activities for goods movement being undertaken, truck management strategies being considered, factors that have influenced the selection of particular strategies, and benefits expected from selected strategies. 
The Transportation Research Board's National Cooperative Highway Research Program (NCHRP) Synthesis 313: State DOT Outsourcing and Private-Sector Utilization examines the outsourcing decision-making process and issues associated with procuring and administering outsourced activities. 
The Transportation Research Board's National Cooperative Highway Research Program (NCHRP) Synthesis 312: Facilitating Partnerships in Transportation Research examines key factors facilitating transportation research partnerships, and presents approaches for producing synergies beneficial to research programs. 
The Transportation Research Board's National Cooperative Highway Research Program (NCHRP) Synthesis 311: Performance Measures of Operational Effectiveness for Highway Segments and Systems examines the use of performance measures for the monitoring and operational management of highway segments and systems. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 308: Owner-Controlled Insurance Programs (OCIPs) provides a brief history of OCIPs, the OCIP experiences of state departments of transportation, contractor issues, and controlling risk, and discusses at length how to choose an OCIP, how to develop an OCIP, and how to operate under an OCIP.
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 307: Systems Engineering Processes for Developing Traffic Signal Systems discusses the systems engineering techniques available to traffic signal systems and identifies the key processes in a number of traffic signal systems engineering areas. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 304: Driveway Regulation Practices provides an overview of current transportation agency practices, recent literature findings, and research in driveway regulation. 
TRB's National Cooerative Highway Research Program (NCHRP) Synthesis 303: Assessment and Rehabilitation of Existing Culverts summarizes the state of the practice of pipe assessment, the selection of appropriate repair or rehabilitation methods, and the management aspects of a pipe program. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 302: Mitigation of Ecological Impacts provides an overview of current transportation agency practices, recent literature findings, and research on measures to mitigate the environmental impact of transportation projects--including the monitoring and evaluation of aquatic environments and related habitats. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 301: Collecting, Processing, and Integrating GPS Data Into GIS includes a discussion of the benefits and problems of integrating Global Positioning System (GPS) data with data from geographic information systems (GIS) and a six-step method designed to help improve the quality of maps and reduce the severity of problems associated with GPS-GIS integration. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 300: Performance Measures for Research, Development, and Technology Programs examines performance measures as they related to research, development, and technology. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 299: Recent Geometric Design Research for Improved Safety and Operations reviews and summarizes selected geometric design research published during the 1990s, particularly research with improved safety and operations implication. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 296: Impact of New Information and Communication Technologies on Transportation Agencies examines the impact that information and communication (I/C) technologies are having on transportation agencies and offers data to understand how agencies are dealing with these impacts. Four classes of technologies were examined: intelligent transportation systems, communication technology, software tools, and remote work arrangements. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 295: Statistical Methods in Highway Safety Analysis focus on the type of safety analysis required to support traditional engineering functions, such as the identification of hazardous locations and the development and evaluation of countermeasures. Analyses related specifically to driver and vehicle safety are not covered, but some statistical methods used in these areas are of relevance and are summarized where appropriate. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 293: Reducing and Mitigating Impacts of Lane Occupancy During Construction and Maintenance describes the current state of the practice for reducing and mitigating the impacts of lane occupancy during construction and maintenance. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 292: Innovative Practices to Reduce Delivery Time for Right-of-Way in Project Development examines the delivery of rights-of-way and property interests for project construction and mitigation activities, and reports on successful strategies employed by agencies to accelerate this process. 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 287: Sleep Deprivation Countermeasures for Motorist Safety concludes that although adequate sleep is the only 100 percent effective "countermeasure" for sleepiness, there are other countermeasures to help make driving safer. Several of the key countermeasures include: 
TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis Report 271: Traffic Signal Operations Near Highway-Rail Grade Crossings presents a review of the current practices associated with the operation of traffic signals at intersections located near highway-rail grade crossings. 
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 264: Modern Roundabout Practice in the United States includes examples of roundabouts and presents information on roundabout design guidelines used in the United States as well as those of other countries. 
