I think electric car revolution will be at least two decades earlier than self-driving.
As far as electric goes we are starting to reap benefits of vast investment in better tech, manufacturing and vehicles purpose built for it.
Self-driving is very far away and the best publicly available systems only do slightly more than lane-assist, the by far simplest part of self-driving.
Couldn't self driving cars in the very near future follow this same path? Find a very densely populated area. Get self driving cars to work very well in that area for short trips. Slowly expand to similar areas?
I haven't followed either of these very closely, so please correct me where I'm wrong.
A special "autonomous park/return mode", say, capped to 10kph, only following a single preprogrammed route, with a complete lead foot on the brake. Nobody would want to ride in an everyday self-drive that had those restrictions, but it's perfectly acceptable for an empty trip to a central parking structure.
The roads around where I live are /already/ at nose to tail capacity at the times I might actually want such a service. What do you think is going to happen when you add electric cars travelling from wherever they're being stored to the customer?
The electric car revolution is going to come at the same time as the self-driving revolution. That will change the calculus of parking significantly. No longer does your car need to be parked right next to your building to be convenient: it can be anywhere a short drive away and summoned at the touch of a button. So charging infrastructure doesn't have to be at every on-street location; it can be centralized to parking lots or garages on a neighborhood basis.