I will never buy a self-driving car, because I like the act of driving too much. I don't understand the appeal to a car that drives itself. It takes all the joy out of cars.
In the fast-approaching 'Internet of Everything' World you will not have a choice. Probably 20 years out. Driving a car by steering wheel will become as archaic as using a Vic 20 to game on.
I would bet serious money it will never be mandated in the US. People won't tolerate losing such an essential freedom. Besides, I can't see companies being able to handle the potential liability. Any accident would forever be the fault of the car company now. Plus, in order for such a system to work, there would need to be a massive database that monitors and controls all traffic and has access to every car's location and destination in order to pre-plot any potential problems with other cars. If it didn't, cars would only be able to react to their immediate surroundings, which would be chaotic and self-defeating.