Within the Office of Mobile Source Air Pollution Control (OMSAPC), a Program Assessment Group has been established to evaluate and direct mobile source control programs. This paper focuses on one input into that evaluation, the development of emission inventory estimates for a variety of mobile pollution sources. Both current (1977) and future (up to 2005) year inventories are estimated. Eighteen different types of mobile sources are considered to ascertain the contribution of unregulated as well as presently regulated sources. Virtually all counties in the United States and its territories are included for one portion of the analysis. The majority of the analyses include only those counties that have the potential to violate the National Ambient Air Quality Standard (NAAQS) for carbon monoxide (CO), ozone (O3) or nitrogen oxides (NOx). This paper begins by projecting future baseline emissions and is founded on a set of assumptions consistent with past air quality analyses. From this baseline the sensitivity of those estimates to the underlying assumptions used is examined. Twelve sensitivity scenarios are considered. In each scenarios one of the baseline assumptions is altered. Then, the result of the alteration is interpreted in terms of its likely air quality impact.

Includes bibliographical references (p. 59). Cover title. "EPA-AA-TEB-81-11." "December 1980."