Why not simply raise gas tax even higher? At some point, employers will have to pay employees so much extra to commute to work that they will adopt work-at-home policies for day to day stuff, and require in-person work for only the most important things.
This is a morally sound policy as well, because when you pollute by burning gas, you are creating externalities - impacting the health of others who have nothing to do with the particular company or their employees. This is exactly the sort of thing that should be heavily taxed. Determining what that tax rate should be is difficult, so...
Eliminate fixed gas taxes. Instead, auction off pollution licenses and require anyone buying gas to also buy an identical number of pollution licenses. Have a fixed number of such licenses available, traded on a marketplace. (Practically speaking, gas companies could buy the licenses and bundle them with the gas sold, so consumers would never have to deal with the minutiae.)
At some point, buying that Tesla becomes much cheaper than filling your car with $20/gallon gasoline. Then, the only thing decided by politics is how many pollution licenses to sell each year (how much pollution are we willing to tolerate.) Even that could be decided by a sort-of vote where you take the median (not mean) number that voters support. Environmentalists could make a case for a very low number, industrialists could advocate a high number, but I suspect the median (not mean!) would result in a very tolerable amount of pollution.