That's one side of the coin, but on the other hand I can also envision self-driving cars enabling more urban density. Presumably self-driving cars don't really need to be parked on-site at the destination and could instead drop off their rider at the destination and park in some centralized parking garage. The car could even make money for its owner by being an automated uber driver while the owner is working or shopping or whatever. American cities give up a lot of space to parking lots, it'd be great to be able to reclaim some of it