"July 1981." Final report. "Author(s): Warren P. Freas"--Colophon. Includes bibliographical references (p. 58). "EPA-450/4-81-025"--Cover.

The Modified Rollback/EKMA Strategy Assessment Model provides a computerized procedure for conducting air quality assessments of national emission control strategies for mobile source related pollutants. Air quality projections of carbon monoxide and annual average nitrogen dioxide concentrations are made using the Modified Rollback equations of de Nevers and Morris. Ozone air quality concentrations are projected using the OZIPP/EKMA procedure. Emission inventories are also projected for each source region and control scenario. Major differences between this model and the earlier Modified Rollback Model are: (1) use of the OZIPP/EKMA procedure for ozone projections; (2) no upper limit on the number of source regions that can be considered; (3) high-altitude and California strategies can be considered simultaneously with 49-State strategies; and (4) the maximum number of mobile source categories which can be listed in the inventory has been increased to 22. The material presented is directed toward the model user familiar with the UNIVAC 1100 System at the National Computing Center. Technical details of the computer programming are discussed and complete descriptions of input and output formats are given. Brief program descriptions and source code listings are provided as appendices.