The odometer has some value though it can't do congestion charging. Still an issue in states where lots of the population is right on the border. If the tax is high it's a big incentive to find a way to register your car in Vancouver, WA. Of course the GPS system also would not have been able to tax out of state cars so easily. Checkpoints at the border have constitutional problems, they impede interstate commerce.

Note that mass transit isn't necessarily the answer. Robin's approach is to let people pay the true cost, and the market will then work it out. I think people do love point to point transportation, do love having a private vehicle they can personalize and put stuff in.

My prediction of the likely trend is fleets of self-driving cars, many privately owned and never shared, many privately owned and rented out when not shuttling their owner, and many always rented out, with mass transit operation on the most dense corridors. Darpa grand challenge produced 1st generation self-driving cars with just a $2M prize. The real prize here is many, many billions, so I think the next generation (crash-avoiding cars safe enough to carry humans and drive streets with pedestrians) is not so far out of reach.