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CMAQ and Public Transportation

An image of a subway train arriving at a station with travelers waiting on the platform.

What is CMAQ?

Jointly administered by the Federal Highway Administration (FHWA) and the Federal Transit Administration (FTA), the Congestion Mitigation and Air Quality Improvement (CMAQ) Program provides a flexible funding source for transportation projects and programs that help improve air quality and reduce congestion.

State and local governments can use the funding to support efforts to meet National Ambient Air Quality Standards (NAAQS) under the Clean Air Act in both nonattainment and maintenance areas for carbon monoxide, ozone, and particulate matter.

For a list of nonattainment and maintenance areas, see

Eligibility Requirements

To be eligible for CMAQ funding, a project must come from a conforming transportation plan and transportation improvement program (in metropolitan areas) or from a State transportation improvement program (in rural areas). State Departments of Transportation (DOTs) are responsible for distributing CMAQ funds. The federal share for most CMAQ-eligible projects is 80 percent, but certain safety projects that include an air quality or congestion relief component (e.g., carpool/vanpool projects), may have a Federal share of 100%. The CMAQ program operates on a reimbursement basis, so funds are not provided until work is completed.

Further, all CMAQ projects must meet these three eligibility requirements:

An image of travelers at a bus stop lining up to board a bus.

CMAQ funds can be used to acquire new transit vehicles like this bus.

Using CMAQ Funds for Transit and Public Transportation Projects

CMAQ funds may be used to support public transportation in four broad categories of transit projects and programs.

  1. New Transit Service. To tap new markets for transit, CMAQ funds may be used to support startup of new transit services, such as new express bus routes or shuttle services linking major activity centers. Although not a permanent source of funding for these services, the CMAQ dollars can support innovation and help determine the viability of new transit services.
  2. System or Service Expansion. Projects designed to attract new riders, typically by providing new transit facilities or services, are eligible for CMAQ funds. Efforts to improve modal connections in major urban areas generally are eligible for CMAQ funding, so long as they reduce overall emissions. Projects can include both constructing and operating new facilities. Improved public transit is one of the Transportation Control Measures listed in Section 108(f)(a)(1) of the Clean Air Act. However, not all transit improvements are eligible for CMAQ funding. The general guideline for eligibility is if the project can reasonably be expected to result in an increase in transit riders. As with all CMAQ-funded projects, an estimate of the resulting emissions reductions must be provided whenever possible.
  3. New Vehicles. CMAQ funds can be used to acquire new transit vehicles (buses, rail, or vans) to expand a fleet or to replace existing vehicles. Alternative fuel vehicles are eligible, assuming they will have a positive impact on air quality.
  4. Fare Subsidies. Under specific conditions, CMAQ funds may be used to support innovative fare policies and financial incentive strategies designed to encourage transit use and reduce exceedances of air quality standards. CMAQ funds may be used to offer reduced fares or free transit or vanpool services when these subsidies are part of an area-wide strategy for reducing emissions during peak periods of ozone pollution. Examples include ozone action programs-designed to avoid exceedances when ozone concentrations are high-coupled with more permanent measures that discourage single-occupant driving.

For any proposed project, the sponsor must document its effects on vehicle emissions so the project can be compared with other CMAQ proposals to allow informed decisions on the best use of available funds.

An image of travelers sitting in a subway car.

Under specific conditions, CMAQ funds can be used to offer reduced fares or free transit service.

Examples of Public Transportation Projects

Maryland, Commuter Rail Coaches

New, higher-capacity coaches were purchased for Maryland’s commuter rail service in the Baltimore-Washington, DC, region.

CMAQ funds: $290,111

Total cost: $7,236,659

Emissions reductions:

Houston, Clean Air Action Program/ Transit Subsidy

A reduced transit fare program was offered in August, when ozone readings are typically highest.

CMAQ funds: $2,625,000

Total cost: $3,500,000

Emissions reductions:

Illinois, Lake Cook Shuttle Bug

An employer-sponsored transit shuttle service operated between a commuter rail stop and a business park in a Chicago suburb.

CMAQ funds: $312,000

Total cost: $390,000

Emissions reductions:

An image of the interior of a subway station showing two sets of tracks and two platforms.

CMAQ funds can be used for improvements that add capacity at transit stations.

New York City, 63rd Street-Queens Boulevard Transit Connection

A subway link was constructed to facilitate travel between Queens and Manhattan. The project alleviated congestion on the jammed E and F lines running through Queens and resulted in approximately 31 hours per year in savings for the average Queens rider on the E, F, and R lines.

CMAQ funds: $44 million

Total cost: $645 million

Emissions reduction:

For more information, please contact:
U.S. Department of Transportation Federal Highway Administration
Office of Natural Environment
1200 New Jersey Avenue, S.E.
Washington, D.C. 20590


This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for use of the information contained in this document. This report does not constitute a standard, specification or regulation.

Quality Assurance Statement

The Federal Highway Administration provides high quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Publication No. FHWA-HEP-13-010

Updated: 1/31/2017
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