Some of the comments here point out how driverless cars would allow people to just call for a car when they need it, a sort of on demand taxi.

I'd like to take it one step further and point out that it may make electric cars even more viable. If a car is going to be waiting until someone calls for one, rather than driving around the city looking for people - we could have a certain factor of "extra" cars charging while they wait.

When you then request a car, the system would send you one that is sufficiently charged. When you arrive the car will reenter the system and recharge.