Not in real cities — NYC works well enough, and $2.75 ($2.50 after bulk discount) takes you anywhere in the city. I’m concerned that self-driving cars will preclude any investment in transit infrastructure, which wouldn’t work well in East Coast cities, since traffic is often limited by routes in/out of the city.
Interestingly, trains would lend themselves better to self-driving than cars. The electric ones don’t have to find fuel or a charge, and their routes are basically determined externally. So you end up with one axis of freedom (accelerate/brake) vs two (steer).
Things like subways would work amazingly well if you could have SHORTER trains off peak running as frequently as on-peak. Automation would lend itself to short trains since you don’t have to hire more motormen and conductors.