I normally drive about 70-75 on interstate (now that I'm older). I drive in the right lane. When I do encounter someone slower than me,( it doesn't happen often, but it does happen) I have a right to pass them so I wait for a break in the left lane and I even speed up some to quickly pass. More often than not, I see people behind me in the left lane speed up to try and force me out of the left lane....riding my tail with an attitude. If there is a group of cars in the right lane I am passing it might take more than a couple of seconds....I refuse to speed up to 90 just to allow someone with an attitude to "rule the road". You have to use some common sense here. I have the right to pass and never try to make anyone mad and I do speed up to upper 70's. Heck, I might even hit 80. I understand because there are those out there only looking for a power trip wanting to force everyone else out of their way. Maybe they never get their own way at home..I don't know..but there is no excuse for making the roads unsafe. Driving 90 makes the roads far less safe than someone trying to stay at or around the speed limit.
On the other hand, I have been behind people who stay in the left lane looking back at me in their rear view mirror, and they simply won't budge to let me by. Then they do finally speed up, passing the vehicle, but stay in the left lane until they get to the next car in the right lane and slow down again. There isn't much that makes me more irritated. There are extremes on both ends that make it intolerable.