There are very little things that can happen totally unexpectedly and that you can avoid once you know about them. Yes, a falling rock can crush your car, but there is not much you can do about it. My point is that if you are driving on a mountain road with a steep cliff, you should be driving slowly. If you see rocks on the road, you can expect larger rocks on the road ahead of you and you should be driving slowly. If you have to make the decision between driving off the road and falling off a mountain, or driving through people, you are driving badly and self-driving cars shouldn&#x27;t be allowed to drive badly.