The goal of reducing vehicle miles traveled (VMT) is an official goal of the U.S. Government policy as it is stated in sections of the Clean Air Act (CAA), the President's 1993 Climate Change Action Plan (CCAP), and in the Congestion Mitigation Air Quality Improvement Program (CMAQ) included in both the Intermodal Surface Transportation Efficiency Act (ISTEA) and the Transportation Equity Act for the 21st Century (TEA-21), U.S.C. 23, Section 149. The relevant sections of the CAA, CCAP, and CMAQ are reproduced below.
(5) Transportation control. (A) Beginning 6 years after the date of the enactment of the Clean Air Act Amendments of 1990 and each third year thereafter, the State shall submit a demonstration as to whether current aggregate vehicle mileage, aggregate vehicle emissions, congestion levels, and other relevant parameters are consistent with those used for the area's demonstration of attainment. Where such parameters and emissions levels exceed the levels projected for purposes of the area's attainment demonstration, the State shall within 18 months develop and submit a revision of the applicable implementation plan that includes a transportation control measures program consisting of measures from, but not limited to, section 108(f) that will reduce emissions to levels that are consistent with emission levels projected in such demonstration. In considering such measures, the State should ensure adequate access to downtown, other commercial, and residential areas and should avoid measures that increase or relocate emissions and congestion rather than reduce them. Such revision shall be developed in accordance with guidance issued by the Administrator pursuant to section 108(e) and with the requirements of section 174(b) and shall include implementation and funding schedules that achieve expeditious emissions reductions in accordance with implementation plan projections.
(1) Vehicle miles traveled. (A) Within 2 years after the date of enactment of the Clean Air Act Amendments of 1990, the State shall submit a revision that identifies and adopts specific enforceable transportation control strategies and transportation control measures to offset any growth in emissions from growth in vehicle miles traveled or numbers of vehicle trips in such areas and to attain reduction in motor vehicle emissions as necessary, in combination with other emission reduction requirements of this subpart, to comply with the requirements of subsection (b)(2)(B) and (c)(2)(B) (pertaining to periodic emissions reduction requirements). The State shall consider measures specified in section 108(f), and choose from among and implement such measures as necessary to demonstrate attainment with the national ambient air quality standards; in considering such measures, the State should ensure adequate access to downtown, other commercial, and residential areas and should avoid measures that increase or relocate emissions and congestion rather than reduce them.
Vehicle miles traveled. No later than 2 years after the date of the enactment of the Clean Air Act Amendments of 1990, for areas with a design value above 12.7 ppm at the time of classification, the plan revision shall contain a forecast of vehicle miles traveled in the nonattainment area concerned for each year before the year in which the plan projects the national ambient air quality standard for carbon monoxide to be attained in the area. The forecast shall be based on guidance which shall be published by the Administrator, in consultation with the Secretary of Transportation, within 6 months after the date of the enactment of the Clean Air Act Amendments of 1990. The plan revision shall provide for annual updates of the forecasts to be submitted to the Administrator together with annual reports regarding the extent to which such forecasts proved to be accurate. Such annual reports shall contain estimates of actual vehicle miles traveled in each year for which a forecast was required.
Vehicle miles traveled. Within 2 years after the date of the enactment of the Clean Air Act Amendments of 1990, the State shall submit a revision that includes the transportation control measures as required in section 182(d)(1) except that such revision shall be for the purpose of reducing CO emissions rather than volatile organic compound emissions. In the case of any such area (other than an area in New York State) which is a covered area (as defined in section 246(a)(2)(B)) for purposes of the Clean Fuel Fleet program under part C of title II, if the State fails to include any such measure, the implementation plan shall contain an explanation of why such measure was not adopted and what emissions reduction measure was adopted to provide a comparable reduction in emissions, or reasons why such reduction is not necessary to attain the national primary ambient air quality standard for carbon monoxide.
President Clinton directed: ... EPA, in consultation with DOT, to draft guidance documents that identify the air quality benefits of innovative transportation strategies to reduce vehicle miles traveled (VMT). These will be used by states and cities in their clean air program development. – Some states and cities have experimented with innovative programs, such as congestion pricing tolls and mass transit finance, which may have significant C02 as well as urban air pollution benefits. – EPA can help States and cities evaluate how well such strategies can work in attaining clean air quality standards, thereby encouraging the adoption of innovative programs.
(a) Establishment. The Secretary shall establish a congestion mitigation and air quality improvement program in accordance with this section. (b) Eligible Projects. – Except as provided in subsection (c), a State may obligate funds apportioned to it under section 104(b)(2) for the congestion mitigation and air quality improvement program only for a transportation project or program if the project or program is for an area in the State that was designated as a nonattainment area under section 107(d) of the Clean Air Act (42 U.S.C. 7407(d)) during any part of fiscal year 1994 and (1)(A) if the Secretary, after consultation with the Administrator of the Environmental Protection Agency, determines, on the basis of information published by the Environmental Protection Agency pursuant to section 108(f)(1)(A) of the Clean Air Act (other than clauses (xii) and (xvi) of such section), that the project or program is likely to contribute to – (i) the attainment of a national ambient air quality standard; or (ii) the maintenance of a national ambient air quality standard in an area that was designated as a nonattainment area but that was later redesignated by the Administrator of the Environmental Protection Agency as an attainment area under section 107(d) of the Clean Air Act (42 U.S.C. 7407(d)); or (B) in any case in which such information is not available, if the Secretary, after such consultation, determines that the project or program is part of a program, method, or strategy described in such section; (2) if the project or program is included in a State implementation plan that has been approved pursuant to the Clean Air Act and the project will have air quality benefits; (3) the Secretary, after consultation with the Administrator of the Environmental Protection Agency, determines that the project or program is likely to contribute to the attainment of a national ambient air quality standard, whether through reductions in vehicle miles traveled, fuel consumption, or through other factors.