It is called the passing lane for a reason. If I'm doing 90 and someone is coming up behind I get over. The lane should be empty minus passing. Nothing is worse than two cars playing back and forth at 65 and 66 mph while a convoy is behind them.I see something similar where by the person is following me close enough (while I'm in the passing lane) that I move over to let them go by. Only to find them going slower a few miles down the road, and they are now "blocking" the left lane. I see a lot of women do this. They seem to be just following along in the left lane, once you move out of the way, they don't know how to keep driving fast.