The city talk is interesting.
Most people in my city don't own cars to begin with. A large percentage of people I know don't drive. My high school had no driver's ed - I had two classmates who could drive by graduation, both lived in the far suburbs. I have friends from h.s. who still don't have licenses. It's not at all a given here that anyone can drive, and it's much more rare to have a car than not, because it's not needed.
Someone upthread, Brutal Mustang, I think, said it'd be no problem in cities if streets were closed to people so cars could run unimpeded, but it'd be a problem in the country. That's just so backward-seeming to me I don't know what to do with it. No, people don't ride horses down the street, but they need to walk across the street all day long. Major cities are often very pedestrian and very public-transit driven. The world's major cities have had public transit moving most of the populous for over a century, and on it rolls.
There'd be no diminished use of cars, because there aren't lots of people in cities using cars to get to work as it is. There are some, but they're people coming in to the city or leaving it, who don't want to take transit, nearly always. People do use cabs in cities, and that might change, but it's changing now, with Uber and the like, so it's just disruption upon disruption. People subscribe to car services now - I can rattle off the numbers of two in my city right now and I don't use them, and they're not the ones used by the people in midtown, who have accounts, where the black cars line up all day moving employees to and fro.
Again, so those drivers wouldn't have their jobs, but there'd be a need for people to maintain the cars, service the cars, put stuff IN the cars to be ferried places, etc. A whole new slew of disruption would crop up. You can't stop progress, and I don't want to stop safety. What worries me is the Dunning-Kruger effect writ large here.
I'd worry that, overall, the people most reluctant to stop, believing they're 'safer' or 'better drivers' than computer-driven cars would actually be the most dangerous people on the road.