I was driving home today on a narrow road behind a dump truck and another pick-up. Dump truck was only doing about 35 on the 45 mph road and the guy in front of me went around him. Dump truck driver wasn't happy as it was a tight squeeze, so he moved out into the center of the lane to make sure I didn't do the same thing. (Which I had no intent of doing in any case. ) Lane positioning works for a lot of road users.