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Transportation Conformity Domestic Scan Report: Use of Latest Planning Assumptions and Transition to MOBILE6

Table of Contents

Executive Summary

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.

Major Findings

During the course of the project the scan team documented many successful institutional and technical procedures and arrangements that have helped facilitate the conformity process in the six areas visited: Harrisburg, Pennsylvania; Raleigh, North Carolina; Dallas-Fort Worth, Texas; Atlanta, Georgia; Tampa, Florida; and Nashville, Tennessee. The scan team found four common themes in efforts to collect and use the latest planning information and to transition to the use of MOBILE6 in transportation conformity. The themes were: 1) All areas were working to add structure and predictability to the conformity process including the updating of assumptions, 2) Institutional coordination was important to a smoothly running process and commanded a significant amount of time on the part of the MPOs, 3) Strong State commitment and leadership is central to ensuring requirements are met and providing technical assistance and resources to MPOs, and 4) Various innovative techniques have been developed to collect, analyze, and prepare data for use in conformity analyses.

In addition, the scan team identified various tools that have been developed, and made note of others that would help to enhance the conformity process and analyses. Although some of these practices and tools are not required by the transportation planning or conformity regulations, we have highlighted in this report those practices that have worked to improve the development and use of planning information in the six areas. The FHWA has posted site visit summary information on the Transportation Conformity Community of Practice website.

Conclusions and Lessons Learned

The scan team and participants found this experience to be extremely useful, and learned from each other. In addition, many examples of good practices were identified that are being used in the six areas visited to improve the quality of planning assumptions and inputs to MOBILE6. Four significant conclusions can be drawn:

For experienced transportation conformity practitioners and those new to the conformity process, this report provides specific examples of techniques, sources and tools that were identified in the six areas that may be helpful in meeting the latest planning assumptions requirement and the implementation of the MOBILE6 model.

Updated: 9/23/2014
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