Why are stop signs in the shape of an octagon?
Road signs were standardized in an effort to make highways more safe for motorists traveling from state to state. This process was begun in the 1920’s, according to an article entitled “The Evolution of MUTCD,” which stands for Manual on Uniform Traffic Control Devices. In 1932, a study group presented their findings to the Mississippi Valley Association of Highway Departments (MVASHD), who revised it for final adoption in manual form. This finalized first volume was approved as the American Standard in November of 1935. The study group determined that the easiest way to standardize road signs was to assign a level of potential danger and associate it with a particular shape. Round signs signified the most threatening situations, octagons the next, followed by diamonds and rectangles as the least threatening. Thus, we see round signs at railroad crossings, which would have been a greater danger to motorists of the time, given the average speed of a locomotive versus a motor vehicle. Ev
