A centrally automated system could — and certainly would — be backed up by per-vehicle AI. Exactly the same way that self-driven cars are backed up by human intelligence.

(Note, I’m not advocating for either approach. I think personal automobiles should be banned, in fact. But I’m at least willing to be honest about how such systems would obviously be designed.)

Obviously not. In such a case, a much better option would be to fall back to the camera system or, worst case, force the car to go into manual mode with a human driver if it detects that nearby systems are unresponsive