Peer pressure will counter initial regulatory hostility. Inevitably there are going to be some early adopter areas and a lot of people scrutinizing what is happening there. When some of those early adopter areas are are getting clear benefits, there's going to be a lot of pressure on neighboring areas to do imitate what their neighbors are doing. From there, it is just a matter of time. Eventually it will turn around and regulation will start making non autonomous driving harder to wield out the remaining accidents involving drunk/tired/incompetent/reckless/etc. drivers.

Insurers will be a major factor here. They should start getting some pretty good insights in accident rates involving AVs vs. normal cars.