ONE hundred years ago, at the end of 1904, local people woke up to find workmen busy placing posts and signs ... road. For example, a red triangle meant caution, while a round red one prohibited ...

They are everywhere anyone goes, and they all exist for different reasons ... they also inform folks of various other things. Road and trail signs let people know where they are going and guide ...

Get Reader’s Digest’s Read Up newsletter for more interesting facts, humor, cleaning, travel and tech all week long. Pink traffic signs ... A yellow stop sign is a different story, though ...