Special "turnout" areas are sometimes marked on two-lane roads. Drive into these areas to allow cars behind you to pass... If you are driving slowly on a two-lane highway or road where passing is unsafe, and five or more vehicles are following you, drive into the turnout areas or lanes to let the vehicles pass.I'm never quite sure if these folks are oblivious, ignorant, or simply trying to somehow "enforce speed limits", but it's annoying and illegal. It doesn't matter if you are going the speed limit. The law states that if you are "proceeding at a rate of speed less than the normal flow of traffic", you need to pull into a turnout and let the traffic behind you pass.
RVs are some of the worst offenders. I especially wish the RV rental shops like Cruise America to hammer this point home with their customers. In fact, it'd be great if I could call or SMS and report one of their renters who is creating a mobile parking lot in their wake. If enough people call in, they get an "asshole tax" levied when they pay.