The Highway Trust Fund is a transportation fund in the United States which receives money from a federal fuel tax of 18.4 cents per gallon on gasoline and 24.4 cents per gallon of diesel fuel and related excise taxes.
The 1956 Act directed federal fuel tax to the Treasury’s General Fund to be used exclusively for highway construction and maintenance.
The Highway Revenue Act, pre-dating the Fund, mandated a tax of three cents per gallon.
[8] As of June 2015, the CBO projected that payments from the Highway Trust Fund to the many states would need to be delayed at some point before the end of federal fiscal year 2015 (i.e., before the end of September 2015) to keep the balance above zero, without either some increase in the federal motor fuel excise tax (or allocation of other revenues to the Trust Fund).
[10] The United States Congress passed a stopgap plan on July 31, 2014 to prevent a funding lapse.
[11] As of 2015, despite a considerable drop in gas prices, there was still little support among the US public and Congress for any increase(s) of the gasoline excise tax.