Underground

You have to hand it to Montreal for being so straightforward with how they've named their metro lines. You look at a Montreal metro map and ask yourself, "Am I on the green line, orange line or yellow line?" Colours. Then you come to London or Toronto or Madrid ( or like anywhere else) and are trying to find your way through the metro and have to remember some  line name or number in addition to the station.... COLOURS, people. Make it easy for your tourists.