automatic cars will 'always' see the hazard and avoid it to a much higher standard than humans. However, they will frequently surprise the human who thinks he could have bent the rule and gotten in and then is surprised the automatic car didn't move out of the way.
I wonder. The sensors can only 'see' so far in front. If I'm on a twisty road with good visibility I'm looking across the corners to see what's coming, and even what's ahead of me in my one and adjusting speed accordingly to avoid having to brake at last minute. The same is true at higher speeds on the motorway. I'm looking way ahead to anticipate a problem, be a necessary lane change, a speed up or slow down to avoid entering a risk zone; and I'm looking in 360 degrees to anticipate action/threats approaching from behind or even to the side; and that threat can be detected many cars in front or the rear.
It might be possible for transponder equipped cars to talk to each other and tell each other what they are doing, but what about what they are going to do? And that will require 100% compatible equipment fitted.
Regarding just the motorway system; it is thought that automatic car control with equal speed and no lane changes, with short spacing, will increase capacity and avoid jams. A steady flow of piston in a cylinder type traffic flow. It might work, but only when there is a 100% compliance. That might then become a requirement to use such roads. It'd be quicker to get from MAN to LON with the car on a high speed train than on the road, perhaps.