This is infuriating, but unfortunately far too common. It's almost like they see you coming and move over intentionally to slow you down. It's just as bad as someone pulling out in front of you on a 2 lane road and then going 5 miles an hour under the speed limit for the next 10 miles in a no passing zone. All they have to do in either of these scenarios is wait maybe 15 seconds and everyone is happy and moving on their way.
But no, they're always in a big damn hurry to slow you down. Drives me crazy.
Just this weekend we were driving through the beautiful mountains of Tennessee into North Carolina and we were behind two pickup trucks that were very obviously going slow so they could look at the pretty leaves. I have no problem with that, but once the line of cars builds up behind you, just use one of the pull off spots and let everyone pass. Did they do this? Nope. Were there signs along the way that "educated" people to do this? Yep.
Did I give them a few courtesy flashes of the headlights after they passed at least 8 of those pull offs to give them a heads up that there were at least 12 cars lined up behind them that they were slowing down with their selfishness? Yep. Did they act rationally and pull off at the next pull off? Nope. The truck directly in front of me came to a complete stop in the middle of the road to express his incredulity at my horrendously offensive act of flashing my headlights at him.
I dropped gear and passed him and moved on down the road. They of course tried to catch up so they could shake their fists at me in disgust, but unfortunately for them, lifted Chevy's with knobby tires don't handle those corners quite as well as the GTI.
Sorry for the novel like rant, but dang they pissed me off. And, before anyone asks, I was not tailgating nor was I driving aggressively. All I did was, after numerous miles of them obliviously slowing us down, was flash my lights.