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Volpe Center Highlights - Fall 2005

Focus

Director's Notes | Focus | Safety | Mobility | Organizational Excellence | Awards
Published and Presented | Volpe Journal

The Volpe Center is home to two internationally recognized facilities for multimodal research and development--the Acoustics Facility and the Air Quality Facility. Major accomplishments of these facilities include designing, developing, and maintaining transportation-related noise models and emissions models used across the nation and the world, and leading the development of a global emissions assessment system, SAGE (illustrated above). As well, the Volpe Center is leading a team that is developing the first system to integrate aviation noise and emissions modeling.

Mitigating Transportation-Related Noise and Emissions

As public concern for the human and natural environment grows, the potential impacts of transportation--such as noise and air quality--receive particular attention. With its strategic goal of Environmental Stewardship, the U.S. Department of Transportation emphasizes its commitment to improving the transportation system while protecting or enhancing the environment. Environmental analysis has become an integral component of the planning, development, and deployment of transportation systems; and state, federal, and global agencies seek sound technical foundations for policies, regulations, and standards. Over the years, awareness of the complexities of these issues has increased, and the Volpe Center has proven to be a valuable resource, providing interdisciplinary support for regional, national, and international noise and emissions initiatives. Among the range of environmental capabilities resident at the Center are two internationally recognized facilities for multimodal research and development--the Acoustics Facility and the Air Quality Facility.

In addition to supporting current initiatives, these facilities work to enhance sponsors' capabilities to meet future requirements for mitigating noise and emissions; to anticipate and create awareness of national and international trends and issues; and to serve as a bridge to industry, academia, and other government agencies. Both facilities are within the Volpe Center's Environmental Measurement and Modeling Division; close ties allow leveraging of capabilities and resources.

Major accomplishments of these facilities include designing, developing, and maintaining transportation-related noise models and emissions models used across the nation and the world, and leading the development of a global emissions assessment system. The Volpe Center's technical support has laid the foundation for many transportation-related policy and regulatory decisions. Current research trends are toward integrating the measurement and analysis of noise and emissions. Enabled by the close alignment of its Acoustics and Air Quality Facilities, the Center is at the forefront of this work, leading a team that is developing the first integrated system of this type for aviation.

Transportation-Related Noise

The Acoustics Facility has been involved in all aspects of transportation-related noise and vibration research and development since the Volpe Center's inception in 1970. In the early years, much of the facility's work was in the areas of community and rail noise. From the late 1970s to the present, most of the work has been in the areas of aircraft and highway noise. The Acoustic Facility supports noise mitigation programs of the Federal Aviation Administration (FAA), Federal Highway Administration (FHWA), Federal Railroad Administration (FRA), and various state and local agencies. Staff members of the Acoustics Facility include Ms. Gina Barberio, Mr. Eric Boeker, Ms. Andrea Goldstein, Dr. Aaron Hastings, Mr. Mike Lau, Ms. Cynthia Lee, Ms. Amanda Rapoza, Mr. Dave Read, Mr. Clay Reherman, Dr. Judy Rochat, Mr. Chris Roof, and Mr. Chris Scarpone of the Environmental Measurement and Modeling Division; Dr. Joseph Burstein, Mr. Paul Gerbi, Dr. Andrew Hansen, Mr. Robert Samiljan, and Ms. Sharon Woods of CSC (a Volpe Center on-site contractor); and Mr. Gregg Fleming, Chief of the Division.

Predicting Highway Noise Levels--TNM

The Volpe Center developed the Traffic Noise Model (TNM) for the FHWA, which recently mandated the TNM for use for all traffic noise analysis in the United States. Above, noise measurement equipment used for "quiet pavements" research.

In support of FHWA, the Acoustics Facility provides technical oversight to the development, validation, and updating of the Traffic Noise Model (TNM), which is used in more than 20 countries to predict highway traffic noise levels. Among other uses, the model can be employed to design effective, cost-efficient highway noise barriers. The first version of TNM was developed in 1998; subsequent versions use advances in personal computing to improve the accuracy and ease of modeling highway noise. Version 2.5 (released in April 2004) reflects substantial improvements to the core acoustics and has undergone comprehensive field validation. The Version 2.5 enhancement is expected to lead to more accurate highway noise barrier design; FHWA has conservatively estimated that the use of the improved TNM will result in an annual cost savings of $20 million per year.

In May 2005, FHWA announced in the Federal Register that the TNM is the official model to be used for all federal-aid traffic noise analyses in the United States.

Studying "Quiet Pavements"

Supporting the California Department of Transportation (Caltrans), the Acoustics Facility is conducting a study to determine the noise reduction benefits of "quiet" asphaltic concrete (AC) pavements. Typically in the United States, noise barriers along highways are used to reduce traffic noise propagating into neighboring communities (since 1970, more than $2 billion has been spent on highway noise barrier construction). In contrast, however, in Europe, quiet pavements are also used to help reduce tire/pavement interaction noise, the noise source most prevalent at highway speeds. Introducing quiet pavements into highway projects can reduce tire/road noise at the source, benefiting nearby communities. In some cases, for example, when noise barriers are not an option, pavement may be the only feasible noise-mitigation tool.

For the Caltrans Quiet AC Pavement Study, tire/road noise is measured on the side of an open highway. Twice a year for five years, simultaneous measurements are performed in five adjacent sections of the highway, each with a different AC pavement overlay. Among other parameters, the noise-reduction benefit of each of the pavements is investigated in terms of pavement age, pavement composition, and vehicle type. Ultimately, this study will contribute to a choice of pavement to be used throughout the state of California and will help build new federal policy on the use of quiet pavements to reduce highway traffic noise. The Volpe Center is also supporting similar activity for the Arizona DOT.

FHWA has started the Quiet Pavement Pilot Program, designed to evaluate quiet pavements in terms of noise reduction benefits and longevity, while ensuring safety to highway travelers. An important part of the program is determining the pavement specifications and maintenance requirements necessary to maintain the noise-reduction benefits for nearby communities. This program is also designed to potentially help introduce quiet pavements as a feature in FHWA's TNM. The Volpe Center is supporting FHWA directly in implementing the Quiet Pavement Pilot Program.

Measuring and Mitigating Railroad Noise

As part of ongoing efforts to improve safety at highway-railroad grade crossings, FRA is conducting research into all aspects of audible warning systems, and the Volpe Center supports this research with experts in engineering, human factors, and acoustics. Volpe Center Acoustics staff performed testing and analysis in several areas, including perceptibility of warning signals inside vehicles, annoyance of residents near grade-crossings due to audible warning signals, and effectiveness of automated horn systems, which are activated automatically by an approaching train.

Also for FRA, the Volpe Center Acoustics Facility updated the Handbook for the Measurement, Analysis, and Abatement of Railroad Noise. Designed in a straightforward, user-friendly format, this document reflects numerous improvements and changes to railroad noise measurement, analysis, and abatement techniques developed since the original 1982 publication.

The FAA's Integrated Noise Model (INM) provides a decision-making tool for airport noise mitigation. The Volpe Center's Acoustics Facility has worked with the FAA to develop and update INM. (View larger image.)

Setting the Standard for Airport Noise Modeling--INM

Between 1982 and 1999, $4.3 billion was spent on noise-mitigation at U.S. airports; FAA's Integrated Noise Model (INM) is the primary tool used by decision makers charged with these expenditures. In fact, the INM is the standard for airport noise modeling and impact assessment in the vicinity of airports in 33 countries. The Acoustics Facility and FAA first developed the INM in 1978; Version 6.2 is expected to be released in November 2005. Version 6.2 reflects the initial results of a multiyear, Volpe-led effort to develop and incorporate in INM a new international standard for the lateral attenuation of aircraft sound, recently adopted by the Society of Automotive Engineers.

Another focus for Version 6.2 was to enable more complete modeling of air tour noise in National Parks for the program discussed in the following section.

Noise measurement equipment gathers data for use by Volpe Center teams in developing acceptable and effective measures to mitigate or prevent significant adverse impacts from commercial air tours in Haleakala National Parks.

Preserving the Peace in National Parks

Congress passed the National Parks Air Tour Management Act of 2000 (the Act) to regulate commercial air tour operations over units of the National Park System. A Volpe Center team comprised of staff from the Acoustics and Air Quality Facilities and the Environmental Engineering Division are supporting the FAA, Western Pacific Region, and working cooperatively with the National Park Service, in the development of Air Tour Management Plans (ATMPs) for all National Parks with commercial air tours. The objective of the ATMPs is to develop acceptable and effective measures to mitigate or prevent significant adverse impacts from the air tours on the natural and cultural resources, visitor experiences, and tribal lands within the parks. Approximately 100 park units will need ATMPs. For more on the ATMP program, visit www.atmp.faa.gov.

Environmental Engineering staff members are led by Mr. Phil Mattson, Division Chief, and Dr. Paul Valihura, Program Manager; their team includes Ms. Nicole Grewell, Dr. Amishi Joshi, Ms. Catherine Mulvey, and Ms. Jennifer Papazian, who, joined by Mr. Bob Hallett of the Service and Operations Assessment Division and Mr. Adam Klauber of the Planning and Policy Analysis Division, are responsible for developing the environmental assessments and impact statements supporting the ATMPs.

A major component of establishing noise impacts is the determination of representative baseline sound levels, or ambient levels for each park. The Volpe Center studies utilize specially designed low-level measurement systems deployed at multiple park sites and collect continuous sound-level data over a period of several months. The most recent upgrade on the FAA's Integrated Noise Model (see subsection above) was designed to better support modeling of air tour noise. In addition to noise analyses in support of ATMPs, the Center is designing and conducting the air quality analyses.

Transportation-Related Emissions and Air Quality

The Volpe Center Air Quality Facility has been involved with all aspects of air pollution including emissions and dispersion measurement as well as computer modeling. The group was started in 1999 with funding from the FAA Office of Environment and Energy (AEE) to support ongoing efforts to study and improve the analysis and modeling of air quality at airports. Work has since expanded to include global air quality issues related to aviation, as well as air quality issues beyond the aviation sector. Staff members of the Air Quality Facility include Mr. Ben Berry, Ms. Andrea Goldstein, Dr. Brian Kim, Dr. Andrew Malwitz, Mr. Anjoli Martin, Mr. George Noel, Mr. Joe Ruggiero, and Dr. Roger Wayson of the Environmental Measurement and Modeling Division; Mr. Sathya Balasubramanian and Dr. John McDonald of CSC (a Volpe Center on-site contractor); and Mr. Gregg Fleming, Chief of the Environmental Measurement and Modeling Division.

Assessing Air Quality Impacts of Airports - EDMS

The FAA's Emissions and Dispersion Modeling System (EDMS) is designed to assess the air quality impacts of airport emissions sources. The FAA requires the use of EDMS in the performance of any air quality analyses for aviation sources. The model is designed to meet both scientific and policy-related needs, and the FAA continues to enhance it to more effectively determine emission levels and concentrations generated by typical airport emission sources. The Volpe Center's Air Quality Facility is engaged in a number of activities that support the continued enhancement of EDMS, including assessing existing aircraft performance methodologies for inclusion, and developing and implementing a detailed, multiyear measurement plan as part of a comprehensive validation effort.

Assessing Global Aviation Emissions - SAGE

FAA's System for assessing Aviation's Global Emissions (SAGE) is capable of analyses on a range of scales, including aircraft, airport, regional, and global. The Volpe Center's Air Quality Facility leads the development of this state-of-the-art technology.

A groundbreaking computer model, the FAA's System for assessing Aviation's Global Emissions (SAGE), is used to predict fuel burn and emissions for all commercial aircraft in the world--more than 30 million flights annually. In support of the FAA's AEE, the Volpe Center, with the Massachusetts Institute of Technology and the Logistics Management Institute, designed and developed SAGE.

SAGE enables the analysis of aircraft emissions on technological, operational, and geographic scales; the model is capable of analyses at single-aircraft, airport, regional, and global levels. FAA's objective is for SAGE to be an internationally accepted model used for evaluating operational-, policy-, and technology-related scenarios to estimate global aircraft emissions. As the only nonproprietary model of its type, SAGE is being considered for formal adoption by the United Nations International Civil Aviation Organization Committee on Aviation and Environmental Protection. The Volpe Center provides technical support for the FAA's activities on the committee. SAGE will also provide the foundation for continued U.S. research in global warming.

SAGE employs parallel-processing technology to evaluate both simulated flights from the Official Airlines Guide and recorded radar flight data from the Enhanced Traffic Management System (ETMS), developed and operated by the Volpe Center's Automated Applications Division. (FAA uses ETMS to track, anticipate, and manage the flow of air traffic.) The Volpe Center team is conducting a comprehensive validation effort to quantify the uncertainty of the model, which may lead to further model enhancements.

Integrating the Analysis of Noise and Emissions

As research tools and approaches have become more sophisticated the interdependencies of noise and emissions have been acknowledged, but are not yet fully understood. Adding to the complexity are the interrelationships of different emissions. Accordingly, the FAA's AEE asked the Transportation Research Board to assist in the design and development of a new Aircraft Environmental Design Tool (AEDT), which will integrate all of AEE's noise, emissions, and dispersion tools. The Volpe Center is leading the effort to develop this multifaceted and comprehensive new tool, supported by ATAC Corp., CSSI Inc., Wyle Laboratories, the Massachusetts Institute of Technology, and the Georgia Institute of Technology.

AEDT is expected to greatly increase the understanding of noise and emission relationships, and open new pathways for systems-level research. Ultimately, it will enable integrated noise and emission modeling on a range of scales, from local to global. Local models will support local and regional regulatory and planning efforts, while global models will support national and international policy development; all models will use the same data sources to help ensure accuracy, transparency, and efficiency.

The Future of Transportation and Environmental Stewardship

Thirty-five years ago, the Volpe Center was established as a new research and development facility with the unique mission of applying innovative technologies and a systems approach to problems across all transportation modes--including the emerging issue of transportation-related environmental impacts. Today, this issue is a strategic goal of the DOT, and the Volpe Center's systems approach is more important than ever to tackling the intricacies of environmental challenges. As part of the Research and Innovative Technology Administration, the Volpe Center will continue its support of the Environmental Stewardship goal by helping its DOT sponsors to anticipate trends, create tools, and develop policies that help ensure that the future holds a safer, more efficient transportation system in a cleaner, healthier environment.

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