Highway Funding:

The Federal Highway Administration's Funding Apportionment Model

RCED-97-159: Published: Jun 5, 1997. Publicly Released: Jun 18, 1997.

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John H. Anderson, Jr
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Pursuant to a congressional request, GAO reviewed the Federal Highway Administration's (FHwA) funding apportionment model.

GAO noted that: (1) FHwA's new apportionment model matches the highway funding formula contained in the governing legislation; (2) the model captures the structure of the overall apportionment process, accurately representing the interrelationships among programs and equity categories and how each builds on the other; (3) the model is internally consistent to the extent that the various parts of it work well together and that the operation of one part does not adversely affect another part; (4) furthermore, the model is adaptable to reflect the provisions of new highway funding proposals; (5) however, the model is complex because of the complexity of current law, and this complexity does not lend itself to the widespread use of the model by staff not trained in its structure and programming language; (6) furthermore, as with any model, the precision of its estimates will depend on the accuracy of the data and subroutines that are used for alternative legislative proposals; and (7) however, GAO found that the FHwA office responsible for overseeing the model does not verify new input data, nor does it have staff with the technical expertise to verify the accuracy of new subroutines developed by the contractor.

Recommendation for Executive Action

  1. Status: Closed - Implemented

    Comments: The Office of Budget and Finance brought an additional staff member in from the Office of Policy Development to assist and check the work of the consultant staff that were adapting and running the model. This individual was responsible for verifying that any changes were accurate from a program and policy standpoint based on the technical assistance requests from the Congress that were being estimated. The Information Systems Division did a single verification of the technical aspects of the model, but did not verify the technical changes to the model made to respond to each adaptation, that is, the changes in the programming language of the subroutines that perform the estimates.

    Recommendation: To ensure the accuracy of the model's estimates and to provide the Congress with confidence in the model's results, the Secretary of Transportation should direct the administrator, FHwA, to establish a quality assurance process to ensure the integrity of any changes to the model's input data and validation of any changes to the model, including new subroutines developed for the model.

    Agency Affected: Department of Transportation


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