if you ever watched air crash investigation documentaries and have seen what can happen with the auto systems on aircraft it is sobering. On one I watched an aircraft on auto pilot had all 3 speed detection probes (pitot heads) freeze up and because the computer got confused that the aircraft was now doing zero airspeed it did something silly and was causing the aircraft to lose height without any alarms going off to warn crew. Plane crashed into sea killing all on board and investigators discovered plane was still in flying attitude (level and horizontal) when it hit sea.
If this sort of thing can happen in aviation where millions are spent on perfecting systems and there is rarely anything close by to hit imagine an autonomous car on crowded roads. Being involved in industrial automation for more years than I care to remember it is pretty much impossible to write programs to cover all eventualities even in a controlled environment, let alone the wild west which is our road system.
Us humans are better than we think we are - computers Poooh
