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CMAQ and MAP-21

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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 CMAQ funds 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

Since its inception, the CMAQ program has provided over $30 billion for more than 29,000 projects across the country.

What's New Under MAP-21?

Enacted in July 2012, the Moving Ahead for Progress in the 21st Century Act (MAP-21) provides funding for the Nation’s surface transportation programs through September 2014. MAP-21 reauthorized the CMAQ program, but it made a number of important changes to how the program operates. What follows is a summary of key changes to the CMAQ program under MAP-21.

Focus on PM2.5

MAP-21 puts greater focus on projects and programs that address fine particulate matter (PM2.5). The law requires that a portion of CMAQ funds provided to PM2.5 nonattainment areas be used for projects that reduce this pollutant.

Funding Formula

A pie chart showing a breakdown of CMAQ projects by project type: shared ride, demand management, pedestrian/bicycle, STP/CMAQ, traffic flow improvements, and inspection/maintenance (I/M) and transportation control measures (TCMs). Transit and Traffic Flow Improvements are about 1/3 each. The rest are about even with STP/CMAQ being slightly larger.

CMAQ Funding by Project Type

MAP-21 brings a new approach to determining funding levels for core formula highway programs. It authorizes a lump-sum total instead of individual authorizations for each program. Once each State’s combined total apportionment is calculated, an amount is determined for the State’s CMAQ program based on a calculation using the relative size of the State’s CMAQ apportionment in fiscal year (FY) 2009.

Available Funding

MAP-21 funds the CMAQ program at approximately $2.2 billion per year. The estimated national apportionments for the CMAQ program (before set-asides for the Transportation Alternatives and State Planning and Research Programs) are shown below.

Fiscal Year Apportionments
FY 2013 $2.21 billion
FY 2014 $2.23 billion
Total $4.44 billion

A State without nonattainment or maintenance areas may use its CMAQ funds for any projects that are eligible under CMAQ or the Surface Transportation Program (STP). States with nonattainment or maintenance areas that received a minimum apportionment in FY 2009 may use part of the current CMAQ funds for any STP-eligible projects.

Transfer of Funding

As under previous laws that authorized Federal surface transportation programs, States continue to have the ability to transfer (or "flex") CMAQ funds to FTA for award as grants.

MAP-21 also changed the approach to the transfer of CMAQ funds to other elements of the Federal-aid program. Transfers of up to 50 percent of CMAQ funds are allowed under MAP-21. States that exercise this transfer authority-cutting available CMAQ funds-could affect traffic congestion and emissions reduction efforts. Progress on those fronts will need to be reported once performance measures that are required under MAP-21 are established.

Funding for CMAQ Projects

State departments of transportation are responsible for distributing CMAQ funds. The Federal share of funding for most CMAQ-eligible projects is 80 percent. However, certain safety projects that include an air quality or congestion relief component, such as carpool or vanpool projects, might qualify for a Federal share of 100 percent. However, this provision is limited to 10 percent of the total funds apportioned to a State under MAP-21.

State and local officials are encouraged to seek a larger local matching share than required by law in cases such as public-private partnerships. The CMAQ program operates on a reimbursable basis, so funds are not provided until work is completed.

Eligibility Requirements

The primary eligibility criteria for CMAQ funding remain the same under MAP-21. To be eligible, 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).

All CMAQ projects must meet these three eligibility requirements:

CMAQ-Eligible Activities

Under MAP-21, CMAQ funds continue to be available for a wide range of transportation projects, but new language in the act emphasizes select project types, including electric and natural gas vehicle infrastructure and diesel retrofits. Eligible activities include (but are not confined to) the following:

MPO Performance Plans

MAP-21 requires each metropolitan planning organization (MPO) meeting the following two criteria to develop a performance plan to achieve targets for emissions and congestion reduction: (1) serving a Transportation Management Area with a population greater than 1 million; and (2) representing a nonattainment or maintenance area. The MPO performance plans must be updated biennially, and each update must include a retrospective assessment of the progress made toward the performance targets for air quality and traffic congestion. The Secretary of Transportation will establish performance measures for States to use to assess traffic congestion relief and reductions in mobile source emissions.

Evaluation of Projects

Under MAP-21, the Secretary of Transportation must maintain and disseminate a cumulative database describing the impacts of CMAQ projects in terms of reducing congestion and emissions. Data collected must include project name, location, sponsor, cost, and cost-effectiveness (based on reduction in congestion and emissions) to the extent already measured. The Secretary, in consultation with the U.S. Environmental Protection Agency (EPA), must also evaluate the cost-effectiveness of projects periodically and share the results with States and MPOs so that they can use them in selecting future projects.

Outcomes Study

MAP-21 requires that the Secretary of Transportation, in consultation with EPA, assess the impacts on air quality and health that projects funded under the CMAQ program have had since enactment of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) in 2005. The study must be conducted by an independent research organization and is funded up to $1 million. A final report on the outcomes study is due in July 2014, 2 years after enactment of MAP-21.

Learn More:
U.S. Department of Transportation Federal Highway Administration
Office of Natural Environment
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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-13-009

Updated: 1/31/2017
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