I don't think it would be that hard. The car constantly sends me notices about many things. If my wife is using the car, I can see an interactive map of where she is, and where she is going. Even with her "driving" I can control the car with my phone. Like any other piece of equipment in the road, I'm still responsible for dealing with it impeding traffic, etc. As far as a flat or mechanical breakdown, it can send me a message, or just summon a tow truck on its own.
I don't either. My point is that putting all on the car is silly. The goal is a total solution, as the redundancy greatly reduces the probability of error. After all, police put up caution tape around accident sites.