The Michigan Man Who Created the Four-Way Traffic Light, 1920

Michigan is home to countless creations, famous entertainers, history, food concoctions…and inventions. Let’s face it – Michigan has cranked out some pretty amazing people, things, and stuff.

One worldwide invention that was created in Michigan was the four-way traffic light. The idea came to Detroit police officer William L. Potts in the late 1910s after constantly witnessing traffic accidents, thanks to the popularity of the automobile growing more each week.

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But what to do about it? He kicked around the idea of a light similar to a railroad signal. So he acquired red and green railroad lights, and even a new light that hadn’t been used before: yellow/amber. Green had originally been used as a ‘proceed with caution’ light until Potts’ creation changed that. Now yellow meant ‘proceed cautiously’ and green now meant ‘go’. The old lights just didn’t give drivers time to slow down and stop, and many accidents couldn’t be avoided. Some towns even tried leaving on the green light simultaneously with the red light for some moments after it changed, but that seemed to confuse commuters even more.

In October 1920, his new creation, a three-color traffic signal tower that could be seen from all directions, was installed for the very first time - at the corner of Woodward and Michigan Avenue in Detroit. After the city acknowledged that the new light did indeed cut down the number of accidents, Detroit installed more, making a total of 15 four-way lights.

William Potts was born in Bad Axe in 1883. When the year 1900 rolled around, then census listed Potts as being 17 years old and a police officer. At 17 years old? I guess it was possible. He passed away in 1947 at the age of 64.

 https://www.youtube.com/watch?v=IVBi7_UsbWM