Road wear is disproportionately caused by heavy vehicles; one study estimated that "one 18-wheeler is equivalent to the impact of 9,600 cars". The gas tax is primarily a subsidy designed to support the trucking industry.
The question of who it is a subsidy to is important, but it is better to directly give them a subsidy than to skew the upstream market towards vehicles that damage roads and cost a ton of money to repair.
I doubt we'll get there though, I admit that we can't get anything effective done. And we'd need to effectively keep prices from rising at the register to even the playing field for infrastructure expenses.
Found it: https://www.gao.gov/products/109954
A couple of caveats: it's from 1979 and deals with interstates only.
We don’t need people in cars.
While some people might enjoy some of the useless consumerism crap that's moved from China to your closest shopping center via trucks, I enjoy driving my old petrol car through the landscape and to the track.
Now let's all step back, calm down and compromise. :)