Have you ever thought about the simple things of everyday life, their history and origin? It’s interesting that when something is so ingrained a part of your life and has been around, we rarely think of it as something that had to be created. Traffic lights, for example. You see it every day; you use it every part of the day, but have you ever wondered why are traffic lights Red, Yellow and Green? Who and when invented the first traffic system? Well, if it is so, you are on the right way. Today is the International Day of the traffic light and you have a very good bet to learn about all these things

The International Day of the traffic light is celebrated on August 5th. The date was not accidentally chosen. The American Traffic Signal Company installed a traffic signal system on 5 August 1914. It was mounted on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio, the USA. The precursor of modern traffic lights had only two colors, green and red. It had also a buzzer, designed by James Hoge. The loud sound of buzzer provided some kind of warning for color changes. It helped police and firemen in case of emergency to control the signals. The first traffic lights needed a special traffic officer to operate the device in a nearby booth. The first three-color traffic light was invented six years later, in 1920, by William Potts, a police officer in Detroit, Michigan. This system included the three-colored red, yellow, and green lights widely used today.

Why did he choose these colors anyway? The reason is quite simple. The colors used by automobile traffic light were essentially adopted from the color system used by railroad engineers as a traffic signal. John Knight, a railway engineer, designed the first prototype of the modern traffic light, based on the railroad traffic system. The chosen colors were strongly associated with the transmitted message. The first color – red – psychologically represented danger or warning, thus it was a stop signal. The red symbolizes the color of blood, unambiguous signal: stop immediately, if ignored, rather serious consequences there could be. In contrast, green is the color of deep calm and assurance; it is one of the perfectly calmest colors, so green was chosen for allowing signal. The yellow – as you know – joined later and had been a modification where yellow light would mean a caution signal.

Hope this information could be useful for you. Enjoy!