Or how about the person who’s been following behind someone in the middle lane for miles contently, then when you approach them from behind in the middle lane and throw on your signal to pass they throw their signal on as well and move out to the left. And of course they don’t speed up to your speed, or even a courteous passing speed. They instead take several minutes to slowly creep by causing you to slow down, and other faster motorists to catch up and cause a blip of congestion due to one persons inability to properly pass.