Keep right except to pass. That is very simple. It doesn't take any analysis to figure that out. So, when you are driving on the Parkway or AC Expressway stay in the right lane except when you are passing. When you are in the left lane and someone pulls right up behind you, get over to the left so they can pass you. Don't make people pass you on the right. It isn't your job to decide how fast traffic should be going. Obey the law and stop creating hazardous highway backups.