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Transportation Conformity Highlights

May 2005

Final PM2.5 Rule Released. EPA published a final rule on May 6 in the Federal Register that addresses PM2.5 precursor emissions in transportation conformity. Specifically, the final rule adds the following transportation-related PM2.5 precursors to the transportation conformity regulations: nitrogen oxides (NOx), volatile organic compounds (VOCs), sulfur oxides (SOx), and ammonia (NH3). The final rule also specifies when each of these precursors must be considered in conformity determinations in PM2.5 nonattainment and maintenance areas before and after PM2.5 state air quality implementation plans (SIPs) are submitted. See:

FHWA Updates Basic Guide to Transportation Conformity for State and Local Officials. FHWA recently updated the Basic Guide to Transportation Conformity to reflect changes that have been made to the transportation conformity requirements since the last update in June 2000. The Guide is currently being printed and the updated Guide will be posted on the FHWA website in the near future.

AMPO Air Quality Workgroup to Meet. On June 27 and 28 the AMPO Air Quality Workgroup will meet in Washington, D.C. Possible topics to be discussed include status of areas meeting conformity requirements for the 8-hour ozone standard and the new PM2.5 rule. For further information contact Rich Denbow at

PM Modeling Workshop Planned. FHWA's Connecticut office is presenting a PM Modeling workshop on May 19, 2005 at ConnDOT's training center in Newington. The workshop is primarily for ConnDOT and DEP employees. For information please contact

Southern Transportation and Air Quality Summit (STAQS) 2005. The FHWA Resource Center in conjunction with EPA will host the next Southern Transportation and Air Quality Summit from August 23-25, 2005. STAQS '05 is an event sponsored by the Federal Highway Administration and EPA Regions 3,4 and 6. The purpose of the summit is to bring together stakeholders from both the transportation and air quality communities to discuss the current and coming regulatory environment, new technologies and current practices vital to the field of air quality and transportation. The summit is geared to practitioners involved with public agencies at all levels. A host of speakers from around the nation will present a number of key topics, best practices and latest information vital to transportation, planning and air quality professionals. For more information contact Mike Roberts at 404-562-3928.

FHWA Resource Center Training Activities.FHWA's Resource Center Air Quality Technical Services Team is available to offer air quality-related training opportunities and information can be found at:

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

FHWA Resource Center Air Quality Team Contacts:

Updated: 11/3/2014
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