Zero? Absolute statements when it comes to anything to do with the law are nearly always wrong.

If we end up with a toll system that tracks where a vehicle goes (which would be necessary for local road tolls), that'll have 4A implications. If we put trackers in cars for the same reason, that'll have 4A implications.

I note those examples because simple odometer readings as a method would also be challenged because much of that usage could be out of state.