Vast majority of accidents are caused by drivers (or cyclers, pedestrians) who fail to safely engage in traffic. For the most part, cars don't kill people - people kill people (or, get themselves killed).
which is exactly why removing people out of the equation is the best way to solve the problem. even fully educated and hyper responsible person is not immune to judgement lapses, hallucinations, heart attacks, strokes, losses of consciousness and many more modes of failure.
what's worst - even if i'm 100% sure about myself, even if i take myself out of the equation - there are still thousands murderous humans driving around me.