I think increasing the payroll tax is a mistake. People who don’t own a car should actually be rewarded because they pollute far less, they don’t disable workers, they don’t require traffic police, they don’t emit CO2…
I would replace the payroll tax with a weight tax on huge SUVs.
Many US states also have annual inspections, although I don’t know about Oregon. They could uneasily record annual Miles here, although the objection is that is overall miles, not miles on state roads, and it only works for cars registered in the state.
While a small number of people may cheat by driving out of state cars, I think this is highly discouraged by insurance civerage