Over the last couple of weeks I've had to make several trips up and down the A12 and I can relate to this. Its depressing enough when one lorry pulls out to make an achingly slow overtake of another, but when it does it to overtake some moron doing 55mph, in a car perfectly capable of maintaining a much higher speed, "bEcAuSE it's the mOSt eCoNOmiC spEEd!!", its rage inducing.
Every morning I get stuck behind people going 35-40 in a 60 for no obvious reason, almost the entire way from home to work :/
Sometimes I can overtake them and they appear to get annoyed by it. I think it's the same handful of people who happen to be commuting at the same times I do. One is a very obese women in a tiny city car which is hillarious. Like Jabba the hut squashed in to a jam jar.