Congestion Mitigation and Air Quality (CMAQ) Improvement Program


The federal Congestion Mitigation and Air Quality Improvement (CMAQ) program provides dedicated federal funding to state Departments of Transportation for projects that improve air quality and reduce congestion. The CMAQ program improves air quality by funding transportation projects and programs that reduce air emissions from cars, trucks and buses (mobile sources) in air quality non-attainment and maintenance areas, which are the only areas eligible for CMAQ funding.

  • retrofit control equipment for diesel engines (e.g., diesel retrofits, engine re-powers)
  • bicycle and pedestrian facilities and programs (also eligible for Transportation Alternatives funding)
  • idling reduction projects
  • Travel Demand Management (TDM) programs
  • Transportation Control Measures (TCMs) that produce air quality benefits
  • education and outreach programs
  • public-private partnerships to implement projects that reduce emissions (public agency sponsor required)
  • rideshare activities
  • transit fare subsidy programs for air quality action days
  • traffic flow improvements
  • intermodal freight projects
  • transit projects
  • vehicle inspection (I/M) programs
  • transit fare subsidy programs
  • Intelligent Transportation Systems (ITS)
  • alternative fuels infrastructure
  • experimental pilot projects


Highway Eligibility

Eligible highway projects include traffic flow improvements, such as traffic signal control systems, incident management programs, high-occupancy vehicle (HOV) lanes and truck climbing lanes that do not increase capacity. Projects that increase highway capacity are not eligible for CMAQ funding, as they lead to increased vehicle emissions. CMAQ funds may be used for projects that reduce congestion as long as those projects achieve reductions in air emissions. Highway rehabilitation and maintenance activities are not eligible for CMAQ funding.

Match Requirements

For most projects, CMAQ funding pays a maximum of 80 percent of eligible project costs. A minimum match of 20 percent non-federal funds is required for those projects. Project sponsors (e.g., local governments or private sector partners) are responsible for paying the 20 percent match. A small portion of CMAQ projects, such as carpool and vanpool projects, qualify for 100 percent funding. To apply for CMAQ funding, click here.