Re: Can we have them
ideally you could "subscribe" to a service where you can get a car within a few minutes, better than a taxi and on call for semi-emergencies, with a regular taxi service as a backup for unexpected demand.
Electric car fans would probably appreciate this kind of service the most. They could _ALL_ be electric, and would re-charge themselves at the "base" where they're all kept.
Ideally the service would include some 'long distance' vehicles that are gasoline powered, but otherwise your average trip to the mall or picking up groceries would be covered by your subscription.
If it's properly managed, cars will "re-arrange" themselves between storage lots as economically as possible, maybe driving you to the store, and parking at a different lot, then getting you at the store, and parking at the original lot [maybe not even the same car, but so what]. That kind of thing.
Best usage would be for people who have a hard time driving or can't get a license for some reason. TOTAL mobility. It's a good thing.
I doubt they'll replace privately owned vehicles, or human-driven vehicles, especially for long trips or "out in the boondocks" excursions. Still, I'm looking forward to seeing these things.
But I doubt they'll replace cabs. Sometimes you just need to have a driver, to handle luggage, for the extra customer service, to get local info from, yotta yotta.
And then public transportation is most likely going to remain cheaper than a "driverless car subscription". But the 'driverless car subscription' should be cheaper than a car payment + insurance + fuel + maintenance (and that would be the selling feature).
A friend of mine used to subscribe to a service where he could get a car to drive with an hours' notice or something like that. It worked pretty well for him until he started driving EVERY day and then he bought one for himself. Up until that point he'd take the train to work. When that became too inconvenient, he started driving. But if it had been available at BOTH ends of the trip, to the station, then from station to work, then back to the station, etc. he might've continued taking the train.