One thing that is kind of interesting about self-driving cars that few people recognize is, because they are programmed to not go over the speed limit, they will actually create more traffic, traffic jams might actually get worse. Because humans tend to drive faster than they are supposed to, the freeways and roads don't get as clogged as they would if everyone was driving at or under the speed limit. Everyone who thinks self-driving cars will help out with traffic might just be surprised to find themselves stuck in traffic because these cars can't act like humans and move a little faster than they're supposed to. Can't remember where I read that, but it was in a study. Law of unitended consequences.