About a year before he left office, he "negotiated" (read: did the Republican thing of shutting down parts of government - in this case, the Department of Transportation - until he got what he wanted) with the legislature both an immediate increase in the gas tax (over 20 cents/gal) and a reformulation of how it worked.

In addition to the base rate, which the tax cannot go below, it basically relies on two major factors - how much revenue it generated during the previous year, and how much it is projected to generate during the upcoming year. (There's also a small adjustment for inflation.) That formula then determines if the tax goes up or down from year-to-year, and by how much.

It was announced in Sept the gas tax would be about a penny less than it was last year, thanks to the increase in driving as people are trying to move past the pandemic, but that still puts us just outside the top-10 for gas tax as compared to other states.