When walked on the sideway, keep your head up and look in the direction you are walking...for when you don't, a sign will magically appear out of no where and scare the hell of you when you walk into it...

P.S. I forgot to warn my son about this discovery and well...last week while downtown, we were walked around a corner, he turned to tell me something and walked right into a sign. No injuries, just a bit of embarrassment on his part.