>> What happens when the car in front goes off a cliff on a twisty mountain road?

Humans have been known to "follow" the car in front of them when its not appropriate. Being parked on the side of the freeway (especially on a curve) is one of the worst places to be. I recall hearing that people hit those parked cars quite often.

I was driving down a two way street, a car parked on the right was facing the wrong way, which made me think I was driving down a one way street. I saw a street light and had to use it to conclude I was in fact not on a one way street and that guy parked illegally.

Fun issues to think about.