This brief originally published in February 2019 and was updated in May 2019.
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 May 27, 2019) the number of years that have elapsed since each state last increased its gas tax. Among the findings of this analysis:
- Eighteen states have waited a decade or more since last increasing their gas tax rates. This number will fall to 15 states later this year when Alabama, Arkansas, and Ohio each implement new rate increases.
- Twelve states have gone two decades or more without a gas tax increase. Alabama will leave this group in September when it implements its first increase in 27 years.
- Two states have waited more than 30 years since last raising their gas tax rates: Alaska last boosted its gas tax in 1970 and Mississippi last did so in 1989. Unless they take action this year, Illinois and Louisiana will be joining this group on January 1, 2020.
Gas taxes cannot adequately fund infrastructure projects unless they are adjusted to keep pace with rising construction costs and structured to offset revenue losses from improvements in vehicle fuel-efficiency. State gas tax rates that have not been updated in many years, or even decades, have seen significant declines in their purchasing power. Those declines are negatively affecting funding of economically vital infrastructure projects.
Fortunately, many states recently have made significant progress in updating their gas tax rates. In total, lawmakers in 30 states have raised or reformed their gas taxes since 2013. This includes states that had resisted doing so for decades such as Alabama, Iowa, Maryland, Massachusetts, Montana, New Hampshire, New Jersey, Oklahoma, South Carolina, and Tennessee.
 These figures are based on the date that each gasoline tax increase took effect, rather than the date on which it was signed into law.
 Davis, Carl. “Most States Have Raised Gas Taxes in Recent Years.” Just Taxes Blog. April 4, 2019. https://itep.org/most-states-have-raised-gas-taxes-in-recent-years-0419/.