Street Sign Shapes

Street sign have specific meanings, based on the shape. The first official stop sign appeared in Detroit during 1915, it was small, white, and square. During 1923, a branch of Mississippi’s highway department suggested a change, suggesting that a sign’s shape could denote the kind of hazard ahead. The more sides a sign has, the more dangerous the upcoming stretch of road is.

Circles (which were considered to have infinite sides) designated the riskiest hazards, like railroad crossings. Octagons denoted the second most perilous hazards, like intersections. Diamonds signaled less-tricky stretches, and rectangles were strictly informational.