I don't see us ever getting to a point where human drivers are prohibited—at least not in the time span where we'd need to worry about converting existing vehic

I don't see us ever getting to a point where human drivers are prohibited—at least not in the time span where we'd need to worry about converting existing vehicles. In the USA at least, driving is so closely associated with the idea of "freedom" that such a move would be politically untenable, no matter the potential for lives saved. Also, I think that once the majority of vehicles are autonomous, the remaining human drivers become less of a danger—I'd argue that most accidents involve two parties making mistakes (even the "not-at-fault" driver wasn't driving as defensively as they could have been). It will be interesting to see how insurance rates change for autonomous vehicles—a vehicle with no potential for manual control should in theory be much cheaper to insure.