Federal motor fuel taxes represent about 91 percent of the revenues deposited into the Highway Trust Fund (HTF) of the Federal government. The large majority of these taxes are motor fuel excise taxes levied on gasoline, diesel, and other special fuels. The motor fuel taxes on gasoline and diesel are 18.4¢ per gallon and 24.4¢ per gallon, respectively. These rates have remained unchanged since 1993 and all but 0.1¢ per gallon is dedicated to the HTF. In addition to motor fuel taxes, the Federal government also collects truck and truck trailer excise taxes, a truck tires sales tax, and a heavy vehicle use tax. These taxes represent the remaining 9 percent of revenue deposited in the HTF. For more information on historical changes to motor fuel excise taxes, view Federal Excise Taxes on Highway Motor Fuel.
FHWA's Office of Policy provides further information on motor fuel taxes and the Highway Trust Fund.