The federal government and many states are unable to adequately maintain the nation’s transportation infrastructure in part because the gasoline taxes intended to fund infrastructure projects are often poorly designed. Thirty states and the federal government levy fixed-rate gas taxes where the tax rate does not change even when the cost of infrastructure materials rises or when drivers transition toward more fuel-efficient vehicles and pay less in gas tax. The federal government’s 18.4 cent gas tax, for example, has not increased in over twenty-three years. Likewise, more than twenty states have waited a decade or more since last raising their own gas tax rates.

Many state governments are struggling to repair and expand their transportation infrastructure because they are attempting to cover the rising cost of asphalt, machinery, and other construction materials with fixed-rate gasoline taxes that are rarely increased.

The chart accompanying this brief shows (as of January 1, 2017) the number of years that have elapsed since each state’s gas tax was last increased.