That is just one possibility, I'm sure there are so many applications I can't even think of them.
Public transport here costs at least $20 a week just for students relatively close to the city. You can expect $50+ for adults, it's not uncommon for people here to live 1+ hours away and commute from the coast, costing $15+ per trip.
One of the interesting effects on this might be 'non-bus' cars. Which is to say public transit as a fleet of say 'four person' self driving cars where you walk to a bus top and touch your transit car and one shows up and picks you up. You tell it where you want to go and it takes you there.
It of course destroys the taxi business quite completely. But combines all manner of public transit into a single service which gets economies of scale. Dynamic electric cars would be fine (where they have an electric 'boom' like trains in Europe do).
Or, perhaps a subscription service, superzipcar or something like that.
Anything is possible, I just can't imagine a (US) municipality that's able to implement an entirely new public service. IIRC, community wi-fi keeps getting sued by companies that want to make money. First, none can afford it. Second the US, IMHO, is really hostile toward any sort of government service.
Even if those were non-issues, you still have to solve the problem of vandalism. People behave like grownups when other people are watching (pretty much). The bus or subway are good examples. Alone, in a car, i think it's much tougher to keep people well behaved. there have been various community bicycle programs that suffer from people beating the hell out of the bikes, or just stealing them.
These are perhaps mutable problems in small towns, or outside of the US.
I imagine that to start with, we'll see certain areas - such as the Vegas strip, perhaps - that support Valet™, a feature first appearing in luxury vehicles that does exactly what we'd already expect from human valet drivers.
But to drill down even further, I'm not exactly sure where the very first Valet™ supported parking lot would be. Manhattan would be a great use-case, but my own guess is that we'll first see this appear at places like large mall parking lots where city regulations won't be as much of a problem.
Bschool professors will talk about how cab companies made the wrong strategic choice even though it will really be the only option and one essentially predetermined.
Personally, I can't wait!
With fewer people having children I think that's less of an issue.