Congestion Mitigation and Air Quality

The CMAQ program provides federal funding for transportation projects and programs to help meet the requirements of the Clean Air Act.

Congestion Mitigation and Air Quality (CMAQ) funding is available to reduce congestion and improve air quality for areas that do not meet the National Ambient Air Quality Standards for ozone, carbon monoxide, or particulate matter (PM) (nonattainment areas) and for former nonattainment areas that are now in compliance (maintenance areas). A nonattainment area is an area considered to have air quality worse than the National Area Air Quality Standards as defined in the federal Clean Air Act Amendments.

Funds are allocated to the following Metropolitan Planning Organizations (MPOs): Puget Sound Regional Council, Southwest Washington Regional Transportation Council, Spokane Regional Transportation Council, Thurston Regional Planning Council, and Yakima Valley Conference of Governments. Initially, CMAQ distributions were based on a factor calculation depending on the air quality issues being addressed (e.g., ozone, carbon monoxide, etc.).  When the factor distribution was eliminated and the 2010 Census released in 2012, the MPOs agreed to continue using the same proportionate share of allocations. With release of the 2020 Census, continuing a factor-based distribution from 2009, seems outdated to continue to address the impacts to the environment. Therefore, we determined to align the CMAQ allocations utilizing the 2020 Census populations, continuing investments in these areas to maintain/improve the air quality.  In addition to this distribution, the Puget Sound Regional Council also receives a set-aside allocation of PM2.5 funds.

Infrastructure Investment and Jobs Act/Bipartisan Infrastructure Law (IIJA/BIL) CMAQ - (federal funding)

Fixing America's Surface Transportation (FAST) Act CMAQ - (federal funding)


The federal bill continues to require WSDOT to report to FHWA annually on CMAQ project obligations and their associated air quality benefits. Data from this reporting is available for viewing in the CMAQ Public Access System at:

166,800 electric vehicle

registrations in Washington in 2023, up from 114,600 in 2022.

87 wetland compensation sites

actively monitored on 918 acres in 2023.

25,000 safe animal crossings

in the Snoqualmie Pass East Project area since 2014.