Congestion Mitigation and Air Quality (CMAQ) Improvement Program

*Calculated (sum of estimated individual State CMAQ apportionments)

Note: Except as indicated, all references in this document are to the Infrastructure Investment and Jobs Act, Pub. L. 117-58 (Nov. 15, 2021).

Program Purpose

The IIJA continues the Congestion Mitigation and Air Quality Improvement Program (CMAQ) to provide a flexible funding source to State and local governments for transportation projects and programs to help meet the requirements of the Clean Air Act. 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 (nonattainment areas) and for former nonattainment areas that are now in compliance (maintenance areas).

Statutory Citations

• § 11115; 23 U.S.C. 149

Funding Features

Except as specified above and below, the IIJA continues all funding features that applied to CMAQ under the FAST Act.

Type of Budget Authority

• Contract authority from the Highway Account of the Highway Trust Fund, subject to the overall Federal-aid obligation limitation.

Apportionment of Funds

• As under the FAST Act, the IIJA directs FHWA to apportion funding as a lump sum for each State then divide that total among apportioned programs.

• Each State’s CMAQ apportionment is calculated based on a ratio specified in law. [23 U.S.C. 104(b)(4)] (See “Apportionment” fact sheet for a description of this calculation)

Set-asides

• 2% for State Planning and Research (SPR). [23 U.S.C. 505]

• For a State that has a nonattainment or maintenance area for fine particulate matter (PM2.5), the IIJA requires that an amount equal to 25% of the amount of the State’s CMAQ apportionment attributable to the weighted population of such areas in the State must be used for projects targeting PM2.5 reductions in those PM2.5 nonattainment and maintenance areas, including for diesel replacements (in addition to retrofits), and the IIJA requires States to prioritize benefits to disadvantaged communities or low-income populations living in or adjacent to such area, to the extent practicable. [§ 11115(5); 23 U.S.C. 149(k)(1)(A) and (B)] States with low population density are not subject to this set-aside under certain conditions. [23 U.S.C. 149(k)]

Transferability to and from Other Federal-aid Apportioned Programs

• A State may transfer up to 50% of CMAQ funds made available each fiscal year to any other apportionment of the State, including the National Highway Performance Program, Surface Transportation Block Grant Program, Highway Safety Improvement Program, National Highway Freight Program, [NEW] Carbon Reduction Program, and [NEW] Promoting Resilient Operations for Transformative, Efficient, and Cost-saving Transportation (PROTECT) Formula Program. Conversely, subject to certain limitations, a State may transfer up to 50% of funds made available each fiscal year from each other apportionment of the State to CMAQ. [23 U.S.C. 126] (See other program-specific fact sheets for additional details.)

Federal Share

• As a general rule, in accordance with 23 U.S.C. 120. (See the “Federal Share” fact sheet for additional detail.)

Eligible Activities

• The IIJA continues all prior CMAQ eligibilities, and adds four neweligibilities:

  • shared micromobility, including bikesharing and shared scooter systems;
    [§ 11115(1); 23 U.S.C. 149(b)(7)]

  • the purchase of diesel replacements, or medium-duty or heavy-duty zero emission vehicles and related charging equipment; [§ 11115(1); 23 U.S.C. 149(b)(8)]

  • modernization or rehabilitation of a lock and dam, or a marine highway corridor, connector, or crossing if functionally connected to the Federal-aid highway system and likely to contribute to attainment or maintenance of national ambient air quality standards (capped at 10% of CMAQ apportionment); and [§ 11115(1) and (2); 23 U.S.C. 149(b)(10), (b)(11), and (c)(4)]

  • in alternative fuel projects, vehicle refueling infrastructure that would reduce emissions from nonroad vehicles and nonroad engines used in construction projects or port-related freight operations. [§ 11115(3); 23 U.S.C. 149(f)(4)(A)]

Program Features

Except as specified above and below, IIJA continues all requirements that applied to CMAQ under the FAST Act.

Assistance to MPOs

• Upon request of an MPO serving a transportation management area (TMA) with population of 1 M or more, the Secretary of the Department of Transportation may assist the MPO in tracking progress made in minority or low-income populations as part of a performance plan. [§ 11115(6); 23 U.S.C. 149(l)(3)]

Operating Assistance

• The IIJA allows CMAQ funds to be used for operating assistance (without time limitation) in association with a transit system located in certain areas. [§ 11115(7); 23 U.S.C. 149(m)(2)]

Additional Information and Assistance

• For more information about this program, visit: https://www.fhwa.dot.gov/environment/air_quality/cmaq/.
• FHWA can connect you with your local FHWA office and support you with technical assistance for planning, design, construction, preserving, and improving public roads and in the stewardship of Federal funds. For assistance, visit:
• https://www.fhwa.dot.gov/infrastructure-investment-and-jobs-act/technical_support.cfm