On average, one-third of state gas tax increases or decrease are passed on to consumers in the retail price of gasoline, according to a new empirical analysis by the ARTBA Transportation Investment Advocacy Center (ARTBA-TIAC). There was no measurable impact after that point, according to the model.

The price of crude oil is the main driver of gasoline prices, the study found. These results confirm previous research that suggest state gas taxes are just one component of a complex pricing process for retail gasoline.

The report examined 113 changes in gasoline tax rates in 29 states between 2013 and 2018, including both legislative and variable-rate adjustments.

“Just like we are seeing in today’s environment, what drivers pay at the pump for gasoline can change dramatically from day-to-day,” said ARTBA’s Chief Economist and study author Alison Black. “And these fluctuations have little to do with state efforts to raise transportation revenues to support much-needed infrastructure investments.”

Between 2013 and 2018, the national average retail price of gasoline fluctuated between $1.70 and $3.79 per-gallon.

Read the full analysis.