In the early 20th century, stop signs weren’t any specific color or shape. Understandably, the lack of standardization confused drivers, so the American Association of State Highway Officials convened in 1922 to select a standard design. They wanted to choose a shape that even drivers coming in the other direction would recognize, so they chose the octagon shape, which isn’t easily confused with signage. They selected a yellow design with black letters, figuring the colors would grab drivers’ attention. They originally wanted red, but back then there was no red dye that wouldn’t fade over time. By 1954, sign makers began using a fade-resistant porcelain enamel. The red color fading was no longer a problem. That year, the Joint Committee on Uniform Traffic Control Devices declared that stop signs would be red with white lettering.
