It seems likely that self-driving cars will start to take over the streets in couple of decades.
Once they have, we need less parking space and cars. Instead of buying a car, most of us will just order an automatic shuttle to take us where we want when we want. Actually, I believe that in twenty years human drivers will be allowed to drive only on small rural roads, not in cities or on highways. For example, in the summer 2015, all Teslas will get an over-the-air update that will enable autopilot mode on freeways.