This is really one of Etiquetteer's pet peeves, so pay attention.
Last weekend Etiquetteer was neatly and innocently waiting at the corner for the light to change when a man trundled alongside about five feet away and asked no one in particular where a local hotel was. Except he thought he was asking someone in particular: Etiquetteer! And Etiquetteer had no idea this was the case. This man was not exhibiting any of the characteristics of actually addressing someone, such as standing at a reasonably close (but not too close) distance, facing them, eye contact, unmistakably audible tone of voice, and the Very Important Introduction of "Excuse me, please . . . " How on earth is anyone supposed to know they're being spoken to by a stranger?
Once Etiquetteer fully understood what was happening, directions could be provided ("That way.") But it also brought to mind a much more unpleasant version of this common problem from about 25 years ago.* Intent on reaching a subway entrance, Young Etiquetteer missed hearing a question being hog-called by some Dreadful Woman** standing ten feet away. And missing the question - and why should Etiquetteer even think it was personally directed in the first place? - this Dreadful Woman started shouting about these Rude Bostonians and how horrible Etiquetteer was not instantly to come to her aid. She clearly thought just standing in the middle of a busy corner made her perfectly noticeable and comprehensible!
If you're in a strange city and you need directions, for heaven's sake, make yourself known to the people whose aid you seek by saying "Excuse me please," facing them, and looking them in the eye. Nobody at a busy intersection is thinking about you to begin with. Help them help you by asking for help in a recognizable, unambiguous manner. That's not just Perfect Propriety, it's common sense.
*Do you ever wake up screaming about things in your past? This is the sort of thing that wakes Etiquetteer up screaming.
**No doubt the British etiquette writer would describe her as Not Our Sort. The American writer Paul Fussell would peg her as a prole.