The Electric Automatic Traffic Signal

Although traffic lights were made in as early as 1868, the ones in the past look nothing like they do today. It was in 1920 that a Detroit policeman, Willian Potts, invented the first four-way and three-colored traffic light. These specific traffic lights introduced the yellow light, a light in between the red and the green to indicate a light change, something we still see on today’s traffic lights. Later into the 20s, more adjustments would be made to traffic lights as they began resembling today’s traffic lights more and more. An example of this would be how the red light was moved to the top and the green light to the bottom. These traffic lights quickly became the standard and had become widespread by the 1930s