Highway programs derive a portion of their funding from user fees such as taxes and charges levied on vehicles and their operators in relation to their use of roads. The motor fuel excise tax, also known as gasoline tax or fuel tax is one of the major contributors of such road user fees. When gas tax revenues over time are considered, it is seen that after years of steady growth, federal and state gas tax receipts have stabilized in the late 1990s. When accounting for inflation, federal and state gas tax revenues are actually declining. Data for the year 2006 for the state of Nevada shows that gas tax account for about 45 percent of total state highway fund revenue.  Any decrease in the fuel consumption will have a huge impact on the revenue available for highway infrastructure maintenance and development.

The fuel tax on gasoline has been based on an amount per gallon of fuel sold, and not as a proportion of the sale price of gasoline. Thus, changes in automotive technologies, fuel prices, and new energy regulations could cause significant reduction in fuel consumption and hence severe reduction in fuel tax revenues.  This will affect the current system of highway financing. A decrease in revenues coupled with increases in construction and maintenance costs for highways will make the future for highway funding one of the most critical issues in infrastructure development and maintenance in the US.