Personally, I hope it never happens. The US is still suffering from when its cities were redesigned for cars, vs. public transit and pedestrians.
Self-driving cars can and will play a very important role in transportation, but cities should be designed around people, not cars.
Edit: I'm by no means criticizing your hope, and I do agree with you that cities should be redesigned to "accommodate" self driving cars, such as "buffer garages" (where autonomous cars are parked in a FIFO way, not in the way cars are parked today), auto-charging stations, smart curbs for pick-up/drop-off, etc.