Not including the cost of crude oil, taxes are the single largest factor in determining how much Americans pay at the pump. Combined, federal and state taxes add more to the price of a gallon of gas than refining costs, retail markup, and transportation expenses.
The federal government and state governments use gasoline taxes to fund road construction and repair. Gasoline taxes also help preserve road conditions by making driving, which wears down on roadways, more expensive.
The federal government levies an 18.4 cent tax on every gallon of gasoline sold in the United States. On top of that, each state imposes its own tax — and in almost every case, the state tax is higher than the federal tax. A handful of states charge more than double the national tax level.