Accidental liability: That's a perennial complaint, but Im struggling to see it.....
Everyone has 3rd party insurance by law, based on make of car, driver details and driver history. In future, insurance companies will have much more accurate data for Volvo self driving accidents per mile than 17 year old little Johnnie with his bird by his side. Where's the difference in process?
If you are saying "but who am I going to lock up dangerous driving", why would you? Dangerous means without due care and attention. Car conforms to safety testing; sometimes it will fail, just like sometimes brakes fail; doesn't mean anyone goes to jail.
Security: I know of three friends who had brake or oil lines cut by vandals. Bad neighbourhoods. And?
City centre traffic: OK, I agreet, it's harder for an unconstrained AI. But lots easier and more freely moving to platoon along high street, and even easier to coordinate at traffic lights using long range 802.11p. Swings, meet roundabouts:)