Research Products
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Multi-Pollutant Emissions Benefits of Transportation Strategies-FHWA (PDF 1.3 MB) November 2006.
Prepared by ICF Consulting for the Federal Highway Administration, this report provides a compendium of traditional and innovative transportation-related control strategies. The report identifies the emissions effects of the strategies on CO, PM10, PM2.5, NOx, VOCs, Sox, and NH3.
MOBILE6 Implementation Experience
The FHWA, in conjunction with the Association of Metropolitan Planning Organizations (AMPO) Air Quality Subcommittee, worked with a group of MPOs to document their experience in applying MOBILE6 in the conformity process. The purpose of this study is to provide an understanding of what steps these organizations took to prepare for use of the new MOBILE model and to identify potential training and technical assistance needs. Specifically, this study documents how MPOs are implementing MOBILE6, what data is being collected locally, how data is being collected, and identifies implementation issues that arose during the transition to MOBILE6. FHWA and AMPO intend to share this information with other MPOs and practitioners who can learn from the experiences of the MPOs that participated in this effort.
Implications of the Implementation of the MOBILE6 Emissions Factor Model on Project-Level Impact Analyses Using the CAL3QHC Dispersion Model August 2004. ( PDF 1.9 MB)
Prepared by ICF Consulting for the Federal Highway Administration, this report discusses how the revisions to the MOBILE model affect the estimation of localized CO concentrations, including problems and difficulties in the interaction of MOBILE6 with CAL3QHC, and recommendations for addressing these issues. In addition, this report discusses how the implementation of MOBILE6 impacts screening assessment procedures.
Regional Emissions Analysis in Small Urban and Rural Areas (PDF 405 KB)
This study documents and assesses methodologies that can be used for estimating regional emissions for conformity analyses in small urban or rural areas. The report provides transportation practitioners a menu of methodologies and techniques for small urban or rural areas to consider for regional emissions analysis. The report also includes an assessment of these methodologies/techniques, and highlights strengths and weaknesses of each.
Emissions Benefits of Land Use Planning Strategies (PDF 3.1 MB)
The purpose of this research is two fold: first, document what land use planning strategies are being considered for reduction of on-road mobile source emissions and how these strategies are being incorporated into various planning activities. And secondly, the study documents the magnitude of the emissions benefits that were estimated and any consideration of relative cost-benefit analysis of the strategies. The study also examined the methodologies being used to measure the impacts of changes in terms of on-road mobile source emissions attributable to land use strategies, and the additional research needs related to emissions benefits of land use strategies.
Transportation Conformity Domestic Scan Report: Use of Latest Planning Assumptions and Transition to MOBILE6
October 2003; Federal Highway Administration
The Federal Highway Administration (FHWA) transportation conformity domestic scan was initiated to identify good practices among a select number of nonattainment and maintenance areas for meeting the transportation conformity requirements of the Clean Air Act. This project was targeted at identifying and sharing good practices in meeting the latest planning assumptions of the transportation conformity process. The study also highlighted areas' efforts to address data issues associated with the transition to EPA's most recent motor vehicle emissions model, MOBILE6. The scan team visited six sites in the eastern and southeastern part of the country and met with key transportation and air quality officials at each location.
Transportation/Air Quality Issues in Rural Areas
April 2003; Prepared by Dye Management Group, Inc. for the Federal Highway Administration
The purpose of this study was to increase understanding of how many rural areas are facing air quality issues and to identify the main causes for their exceeding air quality standards. The study focuses on transportation's contribution to the air quality problems in rural areas and how these areas are meeting certain Clean Air Act requirements related to motor vehicle emission sources.
Environmental Protection: Federal Planning Requirements for Transportation and Air Quality Protection Could Potentially Be More Efficient and Better Linked
April 28, 2003; United States General Accounting Office Report to Congressional Requesters GAO-03-581
This report documents GAO's review of areas that have failed to demonstrate conformity and related conformity issues. GAO reviewed all available data from EPA and DOT, and conducted a Web-based survey of all MPOs and State air quality agencies. They make two recommendations that the relevant Federal agencies consider extending the 3-year time frame between required transportation plan updates and asking Congress to amend the Clean Air Act to change the conformity requirements to match, and to assess the advantages and disadvantages of statutorily requiring that the emissions budgets in air quality plans be regularly updated with new travel data and emissions models.
A PDF copy of the report can be downloaded from the GAO website at http://www.gao.gov/docdblite/form.php?entry=1. You may search by GAO report number (GAO-03-581) or by date.
Exhausting Options: Assessing SIP-Conformity Interactions
January 2003; Winston Harrington, Alan J. Krupnick, and Peter Nelson, Resources for the Future; Arnold Howitt and Jonathan Makler, Harvard University; and Sarah J. Siwek, Sarah Siwek & Associates.
This report evaluates State Implementation Plan (SIP) and transportation conformity interactions based on six case studies: Baltimore, MD; Houston, TX; Paducah, KY; Portland, OR; Sacramento, CA; and Washington, DC.
A PDF copy of the report can be downloaded from the Resources for the Future website at www.rff.org.
State Innovations to Reduce Vehicle Emissions
November 1, 2000; National Governor's Association Center for Best Practices
This report discusses innovative state strategies that achieve and maintain national air quality standards for mobile-source pollutants.
Linking Transportation and Air Quality Planning: Implementation of the Transportation Conformity Regulations in 15 Nonattainment Areas
March 1999; Arnold M. Howitt and Elizabeth M. Moore; Taubman Center for State and Local Government, John F. Kennedy School of Government, Harvard University
This report documents the Conformity Assessment Project which studied the implementation of the transportation conformity regulation in 15 nonattainment areas.
A PDF copy of the report can be downloaded from the EPA website at www.epa.gov/otaq/stateresources/transconf/generalinfo.htm
"Conformity and the New Transportation Covenant"--conference proceedings published in ASCE's Transportation Planning and Air Quality II--May 1993
1994; James M. Shrouds, Federal Highway Administration
The Clean Air Act Amendments of 1990 established a requirement that transportation plans, programs, and projects conform to the purpose of State Implementation Plans for the attainment of the National Ambient Air Quality Standards. This expanded requirement will result in substantial changes to the transportation planning and programming processes, including greater involvement by air quality officials. Similarly, transportation officials will need to play greater roles in the development of air quality plans. The result of these changes is a new covenant between various members of the transportation and environmental communities, one which realigns traditional relationships and responsibilities
