In #Munich, the surface metro is called "S"-Bahn and the underground is the "U"-Bahn. There's this elevator on my way to work that has these three buttons: "O", "S" and "U". Which one would you pick to get to the "S"-trains when you're coming from the "U"-trains?
Over and over I've seen tourists with suitcases make the wrong choice in this elevator. It bothered me so much that I've printed a label to fix the #UX of this #usability disaster.
It's been there for 2 weeks now