Humans are not capable of safely operating motor vehicles. For a combination of practical and psychological reasons, we accept them as safe enough, stuffing the tens of thousands of Americans who get mowed down each year into the backs of our heads. But we know what the genuinely safe version of human-operated vehicles looks like, because we do it for planes, and it involves quite a lot of complex instruments other than the human eyeball.

It would be an absolute catastrophe for the developers of autonomous vehicles to decide there's no need to do better than human drivers.