I have no idea if the 3' rule applies in CA but have only heard about it. What good is this 3' rule if the cops are not going to enforce or even care about it? I am not usually concern if a bus driver is close to me or not, but this man tried to run us off the road by getting really close to us on purpose. He swung wide just to prove a point. We had just turned from a side street onto the main roadway two blocks before his arrival. As I/we looked over at him, through the passenger door, he had his middle finger out for us to view. We had no idea what the beef was with this dude?