Overview of Recommended Models for Hot-spot Conformity Analyses

摘要

In March 2006, the US EPA promulgated a rule establishing transportation conformity requirements for analyzing the air quality impacts of transportation projects on local ambient PM levels. Subsequently, in December 2010, the EPA issued the accompanying guidance for conformity hot-spot analyses for highway and transit projects in PM2.5 and PM10 nonattainment and maintenance areas. The guidance specifies recommended methodologies for the application of air quality models for the determination of the air quality impacts of proposed transportation projects. As a result of the modeling requirements for transportation conformity there has been an increased interest in dispersion modeling techniques applicable for roadway emissions. Two dispersion models are specified in EPA's Guideline on Air Quality Models (Appendix W to 40 CFR Part 51) and the hot-spot conformity guidance, AERMOD and CAL3QHCR.