I suspect that insurance company policies will be what takes ICE vehicles off the road. Not because of the engine, but because collision-avoidance systems in newer vehicles will make older vehicles riskier to insure in comparison, with correspondingly high premiums. ICE vehicles will rapidly become status symbols for the rich.

The same goes for self-driving cars. The technology doesn't have to be perfect before there is a sudden change, it just has to be better than the average driver. The day insurance companies start charging you extra for having a steering wheel is the day that autonomous vehicle adoption will spike.