I rather like the signs on the station platforms at Chicago’s O’Hare International Airport – nice clear visual cues to encourage people to behave sensibly.
It’s something we could do much more of in Britain – especially in buses and in lifts where failing to move forward often deprives others of the ability to get the bus/lift but also where there are usually very few visual cues to encourage people to behave sensibly. I’ve always wondered what would happen if, say, Transport for London tried putting some footstep outlines on the floors of buses to encourage people to carry on walking fully into buses rather than blocking things near the door.
Such signs are by no means the only way to encourage people to physically locate themselves in a sensible location whilst doing something (standing in a lift, waiting on a platform) where people tend not to think about such things very much. For more on that, see my previous post Why do you walk on the wrong side of the corridor in Tube stations?