Funds are allocated to the Federal Lands Highway Program (FLHP) annually from the federal Highway Trust Fund, supported by the federal motor vehicle gas tax and certain excise taxes. These funds may be used only on roads and transportation facilities open to the public (as opposed to administrative and residential roads). As well, these funds may not be used for routine maintenance activities such as snow plowing, patching, and re-striping. All operational and routine maintenance costs remain the responsibility of each agency.
Under the auspices of the Federal Lands Transportation Program (FLTP), the two agencies maintain and improve the quality and condition of some 9,600 miles of public roads (paved and unpaved) and 1,505 bridges and tunnels. Since 1999, alternative transportation projects, such as transit services, also have been supported with FLTP funds.
Prior to 1983, all NPS infrastructure improvement projects—ranging from roads to sewage treatment plants—competed annually for appropriated NPS construction funds. As park visitation increased, there were greater demands for spending on all types of infrastructure. Support for transportation projects was unreliable and the condition of the NPS transportation system was deteriorating. The Federal Lands Highway Program was established with the hope that a dedicated and reliable funding source for park roads from the Highway Trust Fund would reverse this trend.
In 1987, financial support for the program was substantially cut, and remained low until 1998. This decade of reduced funding resulted in a substantial decline in the condition of park system roads and bridges. Circumstances improved in 1998 when federal legislation doubled the annual dollars available. At the same time, however, the FHWA placed controls on spending—these are called "obligation limits." This limitation has reduced the funding available to the FLTP each year by 8% to 16% below the authorized levels.
The result of this funding situation is that funds have been adequate to arrest the steep decline in road pavement conditions, but the overall condition of NPS transportation facilities remains at a much lower level than desirable.