That's basically what human driving is though, no? We consciously and unconsciously take our attention off the task all the time. It's not possible to drive fully alert of surroundings all the time and at least part of the time we are simply dead reckoning in fairly safe lanes of travel at constant speed and direction with minimal pedestrian and cross traffic. I could call it "controlled chaos", "luck", "planning" but there is some amount of unknown when moving a multi-thousand pound object around, and as speed increases so do the chances, ability to optimally correct, and severity of mistakes. It is very interesting and challenging to map the morality of the decisions of moving these machines onto automation.