[jdeibele]

In Oregon, there are two metro areas (Portland and Medford) where vehicles must be tested because of air pollution concerns. If you have a pre-2005 vehicle, I'm pretty sure they still use a measuring device to see how many pollutants your car generates. For model year 2005 and later, they hook their computer to your car's OBDII port and ask the car's computer how it's feeling. If the computer says "fine", they pass you and you can renew your registration.

Comparatively recently, they let mechanics and quick change oil places do the test for 2005 and later cars, giving them the option of charging a fee for it.

Oregon doesn't have vehicle safety inspections but it doesn't seem unreasonable that I could go to the official DEQ or DMV locations if I wanted to have my mileage inspected or maybe pay Jiffy Lube a bit extra because they're closer and their hours are more convenient.

The issue with that is that, though, is the same problem with taxes: many (most?) people aren't going to want to come up with the money to pay their mileage bill on the spot. There don't seem to be great answers for that.

Oregon has a pilot program where they put a device in your car and charge your credit card 1.9 cents per mile. https://www.myorego.org I'm sure that's what they'd like to have people do but I don't know how many people want to do that.