Unlike autonomous driving, public transit is a proven solution employed in thousands of cities around the world, on various scales, economies, etc.

> Redesigning and rebuilding city transportation infrastructure isn't happening, look around.

We have been redesigning and rebuilding city transportation infrastructure since we had cities. Where I live (Seattle) they are opening a new light rail bridge crossing just next month (first rail over a floting bridge; which is technologically very interesting), and two new rail lines are being planned. In the 1960s the Bay area completely revolutionized their transit sytem when they opened BART.

I think you are simply wrong here.

>> In the 1960s the Bay area completely revolutionized their transit sytem when they opened BART.

66 years later we see California struggling terribly with implementation of a high-speed rail system -- where the placement/location of the infrastructure largely is targeted for areas far less dense than the Bay Area.

I don't think there is any single reason why this is so much more difficult now then it was in 1960 -- but clearly things have changed quite a lot in that time.