See also TTI’s Congestion Reduction Strategies website.
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Completed Research
The Future of TDM: Technology and Demographic Shifts and Their Implications for Transportation Demand Management
This research provides a contemporary understanding of TDM through an evaluation of emerging tools and programs and how well those tools and programs are anticipated to be relevant based on the influence of shifting demographics and emerging technologies on travel behavior in Texas. The objective is to evaluate these programs developed 30+ years ago as compared to known shifts in demographics and impacts of technologies to identify where and how the traditional strategies could be leveraged to provide more relevant travel options.
Link to The Future of TDM: Technology and Demographic Shifts and Their Implications for Transportation Demand ManagementCommuter Tax Benefits
This policy brief examines the commuter tax benefit, which is a voluntary benefit program that allows employers to provide discounted or pre-tax transportation benefits to their employees. This voluntary benefit is one of eight types of statutory employee benefits that are excluded from gross income that would be subject to federal tax. Under the program, commuters are able to pay for qualifying transportation expenses with pre-tax income. These expenses are excluded from an employee’s gross income for income tax purposes and from an employee’s wages for calculation of employer payroll taxes.
Link to Commuter Tax BenefitsConnecting Demand Management and Economic Development Activities
Most business decisions on where to locate consider freight and services access, but not the employee access to transportation. Specifically, the current economic development process largely focuses on educating potential businesses about access to transportation facilities with respect to business operations, but the details do not extend to available travel modes for the employees commuting to that work location. As a result, most employer-based programs for travel options are developed after the fact and are somewhat limited in scope and scale. This policy brief presents details on the possible root causes for this disconnect and identifies opportunities for improving the communication and coordination efforts of economic development and transportation demand management efforts at the time of site location decisions.
Link to Connecting Demand Management and Economic Development ActivitiesAustin State Agency Congestion Footprint
Because Austin is the state capital, a high proportion (about 8 percent) of the region’s 880,000 workers are state employees, which makes the State of Texas one of the single largest employers in the Austin metropolitan statistical area. Focusing on the central Austin region
(the area bounded by MoPac on the west, I-35 on the east, Oltorf Street on the south, and US 183 on the north), 19 percent of the 226,000 total workers in that region are state workers. The purpose of this research was to determine the extent to which this large concentration of state workers influences Austin-area congestion.
It's About Time: Investing in Transportation to Keep Texas Economically Competitive
The March 2011 report from the 2030 Committee, “It’s About Time: Investing in Transportation to Keep Texas Economically Competitive”, provides updated details about transportation challenges in Texas and the possible solutions to those challenges. The report was adopted by the Texas Transportation Commission on March 31, 2011.
Link to It's About Time: Investing in Transportation to Keep Texas Economically CompetitiveMobility Investment Priorities Project
The Texas Legislature in 2011 set aside $300 million to get the state’s
highest-priority roadway projects moving, and directed TTI to help the Texas Department ofTransportation and local agencies pursue those projects and explore the best ways to finance them.
Download reports from the Mobility Investment Priorities Project at the following link:
Link to Mobility Investment Priorities ProjectStatus of travel demand management efforts
Most travel demand management (TDM) programs focus on the commute trip, with a goal of reducing peak-hour congestion, although a few programs take a more holistic approach. This brief provides an overview of current TDM efforts (as of spring 2014), including a review of TDM strategies championed by the public sector and recent initiatives undertaken by the private sector.
Link to Status of travel demand management effortsTOol using STAcked DAta
This research effort demonstrates how data from several sources can be layered, so that decisions ensure the best use of available resources. Researchers examined data that illustrated congestion levels, crash frequency, pavement quality, bridge quality, and freight value to create the TOSTADA (TOol using STAcked DAta). A roadway safety project, for example, may also provide improvements in congestion, bridge and pavement conditions and value of freight moved. The stacked data analysis can provide for more comprehensive information for public engagement, improve the understanding of the relationship between transportation costs and benefits and lead to better project comparison and selection processes.
Research in Progress
Mobility Effects of Connected and Automated Vehicles
The advent of automated vehicle technology and its increased popularity have raised expectations about automated vehicles’ future impact on mobility (e.g. congestion reduction, increased throughput, etc.). There is not much empirical data available to refute or fortify such claims. This project examines the mobility benefits, beginning with a review and synthesis of past studies assessing the congestion reduction and mobility improvements from automated vehicles, with the goal of providing quantified ranges of effect.
Future Applications of Innovative Congestion Pricing in Texas
Managed/express toll lanes with variable toll rates have been implemented in Texas and more are planned for major travel corridors in the state. So is there a next step? This research is explores the use of lane pricing in Texas and its potential evolution to additional transportation pricing applications that address congestion. Topics being examined include pricing effects on congestion mitigation, potential business cases for freight and transit, public reaction to paying a direct fee for premium service, and income and geographic equity concerns.
Relationship Between Congestion and Factors Affecting Housing Choice
Understanding where people decide to live and the factors that influence housing location decisions is important to better predict the distance and time that people will live from their work. This project examines demographics, housing characteristics, education quality, and other factors in comparison to traffic congestion levels to gain insight into how congestion affects housing choice. The resulting assessment will enable policy makers to better understand the role of traditional capital or operational improvements and policy and planning decisions in addressing the state’s congestion problem. The assessment will provide insight to a comprehensive policy approach to address urban and suburban congestion.
Update Congestion Reduction Strategy List
Continue previous Rider 42 work in developing a comprehensive list of congestion mitigation strategies to include alternate modes (including transit), additional travel option strategies and new strategies that were identified from 2011 to 2013 but not developed. The 2013 list of the most congested corridors will be reevaluated using the corridor checklists to identify potential locations where these new strategies may warrant additional study. The “success stories” section of the Rider 42 website will also be updated.
Improving Congestion Reduction Analyses
Understanding the benefits from congestion reduction strategies is an important component of a congestion project. A spreadsheet-based method for estimating congestion reduction was developed in the Rider 42 effort; in this project, researchers will improve that technique. A literature review will be completed to assist in updating the estimation tool, and spreadsheet operation will be automated for easier use. The tool will also be revised to incorporate off-peak and weekend congestion reduction components.
Investigating the Linkage Between Congestion and Safety
Utilizing improved analytical tools and building upon work initiated under Rider 42, TTI’s mobility and safety researchers will combine mobility and crash datasets to identify the relationship between congestion levels and safety. The results will be used to estimate the benefits from improved traffic management activities and consequent crash reductions.
Testimony to the Texas Legislature
Tim Lomax Testimony June 23, 2014
Testimony before the Senate Transportation Committee on the work of the Mobility Investment Priorities Project, addressing the state’s most congested roadways.
Download the Testimony
Area Leader
Timothy J. Lomax, Ph.D., P.E.
Dr. Lomax has been extensively involved in urban mobility research for more than 30 years. He developed and applied a methodology to assess areawide traffic congestion levels and congestion costs. The Urban Mobility Report examines trends in urban area mobility in 101 cities throughout the U.S. A related pooled-fund research project has developed several performance measures and analytical techniques to describe mobility to a wide range of audiences including transportation professionals, public policy decision-makers, the media and the general public.
Research in Progress
Update Congestion Reduction Strategy List, Future Applications of Innovative Congestion Pricing in Texas
Email · Tel: 979-845-9960 Ext. 59960
Key Researchers
Karen Dixon
Research in Progress
· Investigating the Linkage Between Congestion and Safety
Email · Tel: 979-845-9906
Phil Lasley
Research in Progress
· Relationship Between Congestion and Factors Affecting Housing Choice
· Congestion Strategies Update
Email · Tel: 979-458-2308
Jason Wagner
Research in Progress
· Mobility Effects of Connected and Automated Vehicles
Email · Tel: 512-407-1106