It won’t be long until government steps in and restricts cars to 80 mph. Self driving cars will not go over posted speed limit.
Self driving cars won’t go over the posted speed limit until they get a speck of road dust on a chip.
We came close to that back in the 80s, when by government edict, speedometers stopped at 85. The theory was that there's no incentive to go faster if you don't have the actual number to brag about at the bar. Proposals were floated to put governors on cars, but it never came to pass.