If you realize the role cops play in day-to-day traffic, you look at things like this from a different point of view. Cops don't give a crap about "rules". They just want to control you. They want to raise your fear of the unknown and instill a sense of submissive respect for them. This allows them to keep the sheep in line. Because they are, after all, shepherds. If the sheep all stay in line, then they can perform their real job of warding off the wolves a lot more effectively. Imagine how hard it would be to deal with the wolves if the sheep didn't obey them, or behaved chaotically and eratically!