> Once all the meatspace human drivers are off the grid, you can remove traffic lights.

As a driver, I've silently tolerated horse-drawn carriages, pedestrians, cyclists, motorbikes, tractors, etc on the roads. And I expect autonomous cars to extend the same courtesy to us drivers. If there's a situation where autonomous cars are incompatible with human drivers, then that situation will have been deliberately created. Human drivers have paid the taxes that built the roadways, in part directly through gasoline taxes, and it would be unfair for large corporations to re-appropriate public infrastructure to further their profits.