Urban Transportation:

Reducing Vehicle Emissions With Transportation Control Measures

RCED-93-169: Published: Aug 3, 1993. Publicly Released: Aug 3, 1993.

Additional Materials:

Contact:

Kenneth M. Mead
(202) 512-2834
contact@gao.gov

 

Office of Public Affairs
(202) 512-4800
youngc1@gao.gov

Pursuant to a congressional request, GAO reviewed the use of transportation control measures (TCM) to control automobile-source emissions, focusing on: (1) TCM effectiveness in reducing pollution; and (2) whether TCM can be implemented in areas that do not have air quality standards.

GAO found that: (1) although traditional TCM are projected to reduce overall emissions by only 5 percent, transportation planners believe that TCM, in conjunction with other pollution reduction programs could help localities achieve greater reductions in air pollution and meet pollution legislation requirements; (2) 56 percent of metropolitan planning organizations stated that TCM would receive strong emphasis in their transportation programs over the next 5 years; (3) market-based TCM that create financial disincentives and attempt to change travel behavior may be more effective than traditional TCM in reducing automobile and carbon monoxide emissions; (4) although the Department of Transportation and the Environmental Protection Agency (EPA) are encouraging states to implement more market-based TCM, such as gasoline taxes or emissions fees, these measures are often costly and economically and politically unpopular; (5) localities that cannot obtain support for market-based TCM can maximize the benefits from traditional TCM by focusing on specific congested corridors and implementing TCM that reduce the number of trips and miles traveled; and (6) more TCM research is needed to determine its overall effectiveness, update literature that is outdated, and help justify future market-based measures.

Recommendations for Executive Action

  1. Status: Closed - Implemented

    Comments: The Department responded that it may not have statutory authority to require local areas to assess the effectiveness of implemented TCM, and that lead responsibility for such a requirement rests with EPA under the state implementation plan process. In addition to encouraging states and localities to assess the effectiveness of implemented TCM, however, DOT and EPA have issued and disseminated reports on TCM effectiveness, and provide related technical assistance to states and MPOs.

    Recommendation: The Secretary of Transportation and the Administrator, EPA, should require local areas to assess the impact of implemented TCM on reducing emissions.

    Agency Affected: Environmental Protection Agency

  2. Status: Closed - Implemented

    Comments: EPA has followed up recent efforts to provide states and localities with methodological tools to assess the effectiveness of TCM. In addition to publishing overviews on the effectiveness of specific TCM and the techniques used to estimate their effectiveness, EPA encourages states and local areas to collect effectiveness data in order to receive emission reduction credit in their state implementation plans.

    Recommendation: The Secretary of Transportation and the Administrator, EPA, should require local areas to assess the impact of implemented TCM on reducing emissions.

    Agency Affected: Department of Transportation

  3. Status: Closed - Implemented

    Comments: EPA has worked with DOT on a number of efforts to ensure states and localities have adequate information on TCM effectiveness. For example, EPA and DOT have completed a joint report to Congress on the effectiveness of TCM, and disseminated the report to state DOTs and air quality agencies, and MPOs. Also, EPA and DOT have funded a grant to the National Association of Regional Councils (NARC) to develop and disseminate information through manuals, reports, brochures, regional conferences, and workshops. NARC will prepare a document on TCM effectiveness and develop a series of outreach/education materials for metropolitan planning organization decisionmakers.

    Recommendation: The Secretary of Transportation and the Administrator, EPA, should cooperate in gathering and disseminating this updated information to states and localities in ozone and carbon monoxide nonattainment areas.

    Agency Affected: Department of Transportation

  4. Status: Closed - Implemented

    Comments: The Department of Transportation has completed a joint DOT/EPA report to Congress on the effectiveness of TCM, and disseminated the report to state DOTs and air quality agencies, and MPOs. Other DOT efforts are ongoing, including a consultant report overviewing existing literature on TCM effectiveness, and development of TCM evaluation tools.

    Recommendation: The Secretary of Transportation and the Administrator, EPA, should cooperate in gathering and disseminating this updated information to states and localities in ozone and carbon monoxide nonattainment areas.

    Agency Affected: Environmental Protection Agency

 

Explore the full database of GAO's Open Recommendations »

Sep 26, 2016

Aug 15, 2016

Jul 26, 2016

Jul 21, 2016

Jul 14, 2016

Jul 7, 2016

Jun 14, 2016

Looking for more? Browse all our products here