The motor fuels tax pays for many of the transportation projects in Texas. Currently, the State of Texas charges a flat 20 cent per gallon tax on gasoline and diesel fuels. The state puts 15 cents of that into the Highway Fund. The remaining 5 cents goes to public education. The tax rate has not increased since 1991. Texas ranks 42nd among states in terms of its state gasoline tax rate. Some want to increase this tax to cover ongoing highway costs.