Why all the edge cases?
I don't get it. The objections to car autonomy are always weird edge cases. When on deity's earth do you choose between an artic and 15 pedestrians... AFAIK the vast majority of accidents are lapses of concentration of the driver and/or over-confidence.
Computer cars suffer neither of these. As others have pointed out, the 'puters only need to be better than the average meatbag for it to reduce deaths. If the auto car gets confused, it'll just slow down and maybe stop, and so will all the other auto cars behind it. No more pile-ups.
Oh, and no road rage deaths/injuries. Ever.