The fundamental problem which is impossible to solve is game theory.

Suppose the collision avoidance is perfect. Now put it on the roads of NYC, or New Delhi.

There are a lot of people who will just walk in front of a car going 40mph, if they know for sure it will brake hard and stop.

The problem isn't technology, it's humanity.

The solution is to change the rules of the road, have protected lanes for self-driving buses and taxis and cars, and enforcement.

Let vehicles that can take full advantage of communicating with each other and the road go fast and use the infrastructure to maximum theoretical capacity, without having to worry about dumb human drivers.