Illinois is ahead of the curve and instituted an automatic annual gas tax increase in 2019 so they don't have to think it through anymore. They did propose instituting a $1000 annual registration fee on electric vehicles (it was $100 on "regular" cars), but after pushback decreased that to $250 (while increasing gas vehicle registration to $150).
"California pumps out the highest state gas tax rate of 66.98 cents per gallon, followed by Illinois (59.56 cpg), Pennsylvania (58.7 cpg), and New Jersey (50.7 cpg). The lowest state gas tax rates can be found in Alaska at 14.98 cents per gallon, followed by Missouri (17.42 cpg) and Mississippi (18.79 cpg)."
https://taxfoundation.org/state-gas-tax-rates-2021/
I wonder if other states will start increasing car registration fees in lieu of gas tax revenues (or simply increase gas tax). The other things that crushes me in Illinois is the spread between regular and mid/premium gas. It's like 40-50 cents/gallon each (i.e. regular --> mid price increases 40-50 cents gallon, another 40-50 cents gallon increase between mid and premium. So, yeah could be paying $1 more/gallon for premium in IL. Apparently, the nearest refineries only product 87 so they have to go to farther away refineries for the other stuff...). One of my vehicles says "premium only" (I go mid-grade, which according to mechanics/message boards etc. for said vehicle is okay). In most states, I believe the spread is much less though.