In Great Britain the Motorways, as we call them, have a slow lane, a fast Lane and an overtaking lane AND trucks are NOT allowed in the overtaking lane by Law. It is also quite unusual to see the changing of lanes without indicating first. Many of the American drivers I have come across, either don't indicate at all when changing lanes, or when they do, consider it their God Given right to move into the next lane "No Matter What". I have worked in MOST U.S. States and find my comments on these matters quite general.
TERRYR