When “auto piloted” cars have a higher probability of safely delivering us to our desired destinations than driving ourselves, a sound argument can be made for policies supporting their use on the open road.
This, however, misses the enjoyment we sometimes derive from doing the driving ourselves, even if there is an increased risk for so doing. “No problem” you say; “surely we will get to choose whether to use an autopilot system or not”. I think this is true, but I also think that, because of how dramatically auto piloted cars can increase per-lane traffic flow, we may see roadways that are only open to auto pilot cars, just as our interstate highways today are only open to motor vehicles, and not to “horses, ridden, driven, or led”.
And, because our human intuitive statistics is driven so strongly by what we see and not by the evolutionarily recent invention of effective and extensive statistics, the first accident that occurs with a Tesla Auto Pilot system will result in a rash of media attention and a fall in stock price. No matter how many orders of magnitude lower the actual risk from using the Auto Pilot system is in fact.