Should I stay or should I go? Find out why a large-scale effort to improve crosswalk safety in the U.S. and Canada crashed and burned, on this episode of Now I Know. About five years ago, municipalities across the United States, Canada, and likely points elsewhere began installing new technology for crosswalk safety. Gone were many of the simple “WALK” or “DON’T WALK” signals. They were, instead, replaced by ones with countdown clocks, telling pedestrians how much time they had before they could no longer safely cross the street.