I have always been intrigued by the fact that there are no barriers at the Grand Canyon (anywhere, that i know of) and yet I haven't heard of anyone going over the edge, while I'm certain it has happened. People do use their heads if given the opportunity.
My one close call came in Chicago where they have one way streets for cars but yet buses go the opposite direction. Almost bought the farm there years ago. Don't know if it is still that way but it certainly got my attention. Had I not been walking with an associate I wouldn't be typing this sentence.
