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Transportation Conformity Highlights

December 2004

EPA Announces Final Designations for Fine Particulate (PM2.5) Standard. On December 17, EPA notified 20 governors that certain areas of their state do not meet the nation's first fine particulate (PM2.5) standard. All or part of 224 counties nationwide are designated nonattainment under the PM2.5 standard. For more information, see:

EPA Issues Supplemental Conformity Proposal for PM Hot Spot Analysis. On December 7, EPA released a supplemental notice of proposed rulemaking (SNPRM) regarding transportation conformity options to address PM-2.5 and PM-10 hot-spot analyses.

On July 1, 2004, EPA promulgated final transportation conformity regulations to address the new 8-hour ozone and PM-2.5 air quality standards. However, at that time they did not finalize any criteria or procedures to address localized PM-2.5 emissions impacts of individual projects. In the November 2003 proposal, EPA had presented several options concerning hot-spot analyses in PM-2.5 and PM-10 nonattainment and maintenance areas. However, EPA received substantial comment on this issue, and decided to request further comment on additional options regarding hot-spot analyses.

Options under consideration in this supplemental proposal include:

Note, until any changes to the PM-10 provisions are finalized, the current provisions of the Transportation Conformity Rule apply. Currently, qualitative hot-spot analyses are required for all non-exempt projects in PM-10 nonattainment and maintenance areas.

State DOTs and MPOs are strongly encouraged to comment on this SNPRM. The final option selected could have an impact on both the conformity and NEPA processes, as the hot-spot analyses are typically completed as part of the NEPA process. The SNPRM is available on EPA's website at

AMPO Air Quality Work Group Meets in Houston. The Association of Metropolitan Planning Organizations (AMPO) Air Quality Work Group met on December 13 and 14 in Houston, Texas. Agenda items included: diesel retrofit implementation experiences, conformity in the Dallas - Ft. Worth, Houston and Atlanta metropolitan areas, FHWA research projects on regional emissions analysis in small urban areas and emission benefits from land use strategies, EPA updates on PM issues and the MOVES model, updates on TEA-21 reauthorization and the national conformity picture, a discussion on training and technical assistance needs, and a roundtable discussion on experiences with air quality and conformity. For additional information contact Rich Denbow at

NTI Course: Introduction to Transportation Conformity. Courses will be offered in Montgomery, AL on January 25 - 27 and Houston, TX on March 21-23, 2005. Additional courses are to be scheduled in February and April. For information and to register go to:

FHWA Resource Center Training Activities. FHWA's Resource Center Air Quality Technical Services Team will be conducting the following air quality-related training opportunities over the next several months.

Transportation Research Board: Transportation and Air Quality Committee Activities. At the January 9-13 Annual Meeting of the Transportation Research Board, the Transportation and Air Quality Committee will host the following activities. All sessions will be held at the Hilton Hotel.

If you have any suggestions for future monthly conformity highlights, please email:

FHWA Resource Center Air Quality Team Contacts:

Updated: 10/20/2015
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