Humans ARE driving to that standard right now. Deaths per mile are vanishingly small in the grand scheme of things.
Yeah, but we shouldn't have a double standard. If we could get an AI to reduce the number of deaths in half it would still be worthwhile.
Besides, non-fatal ACCIDENTS per mile are much more common, and we should be able to determine if those are reducing a lot faster.
By the time humans have been proven superior there is a real chance that the AIs will have improved to be superhuman. The experience in gaming is that state of the art goes from ok vs amateurs to superhuman quite quickly.