Contact Us


All News Releases By Date


EPA Refines Mobile Source Emissions Estimate Model

Release Date: 05/19/2004
Contact Information:

John Millett, 202-564-7842 /

(05/19/04) EPA is announcing the availability and official approval of MOBILE6.2 for use in state implementation plans (SIPS) and transportation conformity analyses. EPA is also announcing the availability and official approval of new methods for estimating emission factors for "re-entrained road dust" which is particulate matter that is kicked up by cars going over the road and from wind generated by the car's movement. It is listed in the December 2003 revision of EPA's Compilation of Air Pollutant Emission Factors commonly referred to as AP-42 re-entrained road dust. MOBILE6.2 is EPA’s emission factor model for calculating emissions from highway mobile sources of air pollution. This update in the MOBILE6 series adds the capability to estimate particulate matter (PM) and toxic emissions from cars and trucks. MOBILE6.2 is the first model to integrate the estimation of particulate and toxic emissions into the MOBILE series and it gives users a single, consistent way to model all the major highway vehicle pollutants. MOBILE6.2 uses the most up-to-date science, information, and tools available today to determine the levels of carbon monoxide, hydrocarbons, particulate matter, oxides of nitrogen, and air toxics emitted by highway vehicles. The release of the model is part of EPA’s ongoing effort to continuously improve mobile source modeling. Because MOBILE6.2 incorporates the latest EPA standards for particulate emissions from motor vehicles, it will allow states to properly take credit for substantial additional reductions as they develop plans for attaining PM10 and PM2.5 air quality standards. Today’s Federal Register notice establishes a two-year period before MOBILE6.2 and the December 2003 AP-42 methods are required to be used in transportation conformity analyses for PM10. This period gives states the time they need to determine the impact of MOBILE6.2 and the December 2003 AP-42 methods on transportation conformity determinations. Additional information, including an EPA guidance document on SIP and conformity policy regarding MOBILE6.2 and AP-42 is available at: .