If you are using that lane and see someone faster coming up behind you you get out of the way

This is the crux of it, and what is so fucking annoying driving in Washington State, USA. We have the worst drivers in the country here, and people will be cruising along at 15mph under the speed limit in the left lane, keeping pace with the driver in the right lane, completely oblivious to everything going on around them. To make matters worse, they hit their brakes at every sweeping curve, curves designed so that drivers don't have to slow down. It's infuriating.