Comment submitted by Laurel L. Kroack, Chief, Bureau of Air, Illinois Environmental Protection Agency (Illinois EPA)

The Illinois Environmental Protection Agency (Illinois EPA) appreciates the opportunity to comment on the proposed restructuring amendments to the transportation conformity regulation published in Federal Register on August 13, 2010. The Illinois EPA supports the proposed restructuring to the transportation conformity regulation intended to simplify the application of the requirements for the adoption of new or revised National Ambient Air Quality Standards (NAAQS). These modifications, pertaining to the types of budget tests and analysis years should facilitate the applicability of the regulations in areas newly subjected to the updated NAAQS. The Illinois EPA strongly supports the proposed revision to the regulation which would require the use of a conformity analysis year that is within five (5) years of the conformity determination year in those instances where an area’s attainment date may have passed. The use of an earlier analysis year is more protective of air quality and human health as it more accurately assesses the impact of the proposed transportation program. Emissions estimations from later analysis years are affected more by the makeup of the vehicle fleet, which will contain an increasing percentage of vehicles that meet the more stringent Tier 2 emissions standards. Thank you again for the opportunity to provide our comments on this proposal.