'Transportation control measure' has been defined by the Environmental Protection Agency (EPA), to mean any measure such as reducing vehicle use, changing traffic flow patterns, decreasing emissions from individual vehicles, or altering existing modal split patterns, that is directed toward reducing emissions of air pollutants from transportation sources. Transportation control measures are required for any air quality control region where controls on stationary sources, combined with the Federal Motor Vehicle Control Program (FMVCP) placing emission standards on new cars, are inadequate to insure attainment and/or maintenance of the ambient standards.