It seems to me that this is less about "following" the law, and more about being safe. The car that was rear ended might have stopped for any number of reasons,

It seems to me that this is less about "following" the law, and more about being safe. The car that was rear ended might have stopped for any number of reasons, the tailgater is going to hit the stopping car. And the google car actually didn't follow the letter of the law at the 4 way stop. It also has been programmed to wait for others, in case they are breaking the law. If everyone followed the law 100% everyone would be safer. I'm not saying the laws are perfect, but the issue discussed here is more about what the self driving car is doing that isn't covered by law