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Program Assessment


View Assessment Details

Mobile Source Air Pollution Standards and Certification

EPA's Mobile Source Standards and Certification program protects public health by limiting harmful emissions from mobile sources of air pollution. EPA is required by the Clean Air Act to set emission standards for all categories of new engines and vehicles.


What This Rating Means

Moderately Effective

In general, a program rated Moderately Effective has set ambitious goals and is well-managed. Moderately Effective programs likely need to improve their efficiency or address other problems in the programs' design or management in order to achieve better results.
  • The program is well-designed, well-managed, and has contributed to reduced air pollution from mobile sources. Emissions of key air pollutants from motor vehicles per vehicle-miles-traveled have decreased substantially since enactment of the 1990 Clean Air Act Amendments.
  • The program's regulations are developed with input from a wide range of stakeholders. The rulemaking process includes extensive outreach and coordination with stakeholders throughout the full range of regulatory development. Information obtained from this outreach, which ranges from written comments to facility visits, is reflected in rulemaking documents.
  • Mobile source programs initiated within the last decade are expected to further reduce emissions and will contribute to meeting future targets. However, mobile sources remain a significant contributor to air pollution in the U.S., and EPA data indicates that nearly half of Americans still live in areas with unhealthy air.

Improvement Plan

About Improvement Plans

We are taking the following actions to improve the performance of the program:

  • Improving efficiency measurement so that it can be used to continuously improve program management.
  • Reviewing existing regulations to ensure consistency and to ensure that the program has the most cost-effective rules in place.

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