We don't have to go that far; anyone who thinks an autonomous car could compete in normal weekday midtown Manhattan traffic hasn't had the pleasure. You have to change lanes constantly to avoid double- and triple-parked trucks and taxis, and street construction – and every lane change is a little game of low-speed Chicken, in which each driver pretends they don't care if they get hit, and presumes that the other will yield. Autonomous cars can't pretend; every human driver will know that they have to avoid accidents whenever possible. And paid human drivers will be particularly eager to block their progress, to penalize their passengers.