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What GAO Found

During fiscal years 2009 through 2011, four administrations within DOT obligated about $144 billion from the HTF. FHWA obligated the largest share--about 81 percent--of this total, specifically:

  • FHWA obligated $116.7 billion from the HTF. A majority--about 81 percent--was obligated to construct and maintain highways and bridges. The remainder was obligated for other purposes such as safety, debt service, traffic management and planning and utilities, and for transportation enhancements.

  • FTA obligated about $24 billion--about 17 percent of the total obligations--from the HTF, almost all of it through grants to local and state transit agencies and governments to provide transit service, including grants for capital projects, planning, and operating assistance.

  • NHTSA obligated about $1.9 billion from the HTF mostly in safety grants to states and localities.

  • FMCSA obligated about $1.6 billion from the HTF for motor carrier safety grants to states and localities and to support their efforts to enforce federal commercial motor carrier safety standards.

Why GAO Did This Study

The Highway Trust Fund (HTF) was established to finance the construction of the Interstate Highway System. This system, built in partnership with state and local governments over more than 50 years, has become central to transportation in the United States. During this same time period, the federal role in surface transportation programs expanded to include a broader mission. Surface transportation programs have grown in number and complexity, and while most federal surface transportation funds remain dedicated to highway infrastructure and administered by the states, many of these programs now serve additional transportation, environmental, and societal purposes.

In 2005, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) was enacted, authorizing a total of $244.1 billion for highways, highway safety, and public transportation. The HTF serves as the funding source for most of the authorized programs. In addition to authorizing funds for construction and maintenance of highways and bridges, SAFETEA-LU specified additional purposes for which funding must or may be used, including, but not limited to, safety; metropolitan and statewide transportation planning; transit; and transportation enhancement activities, such as pedestrian and bicycle facilities and environmental mitigation of highway impacts on wetlands and wildlife. Within the Department of Transportation (DOT), the administrations responsible for the programs funded from the HTF are the Federal Highway Administration (FHWA), the Federal Transit Administration (FTA), the Federal Motor Carrier Safety Administration (FMCSA), and the National Highway Traffic Safety Administration (NHTSA).

After SAFETEA-LU expired at the end of fiscal year 2009, it was extended several times until the enactment of the current surface transportation authorization, the Moving Ahead for Progress in the 21st Century (MAP-21). Although federal surface transportation programs were reauthorized for 2 fiscal years under MAP-21, the future of the HTF remains uncertain. The HTF balance was about 30 percent lower at the end of fiscal year 2012 than it was at the beginning of the fiscal year. Current Congressional Budget Office projections show that by fiscal year 2015, absent any legislative changes, the HTF will be exhausted. We have placed federal surface transportation funding on our High Risk List because of erosion of HTF revenues while demands increase to repair and upgrade the system.

MAP-21 mandated that we report on activities funded from the HTF including for purposes other than construction or maintenance of highways and bridges in fiscal years 2009 through 2011, including information similar to the information in our 2009 report on HTF expenditures. To meet the mandated reporting date on December 3, 2012, we provided your offices with preliminary information. This report expands upon that letter with more specific information about total authorizations from the HTF for fiscal years 2009 through 2011, authorizations and obligations by DOT administration, and the types of projects funded from the HTF.

For more information, please contact James R. McTigue, Jr. at (202) 512-2834 or

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