It is states which have annual or biennial inspections, so can report true mileages to the state DMV, which would collect the money as part of vehicle registration. (Yes, they could spread it out with monthly payments, the way auto insurance companies do.) What Congress would be happy to do is reduce the current federal gas tax, and stop sending the money to the states. That would give state legislatures a powerful incentive to enact a new and more logical tax. Admittedly some of them would balk, but they could rationalize it as not a new tax at all, but a pro-states-rights replacement for a previously existing one.
Ray