That yellow traffic light? It was the invention of a Detroit police officer

Aug 12, 2014

Credit User: #96 / Flickr

    

It's hard to imagine driving without the guidance of the tri-color traffic light, isn't it?

Turns out, that tri-color light that keeps us from crashing into each other at intersections was the brainchild of a Detroit police officer.

Matt Anderson is curator of transportation at The Henry Ford museum complex. Anderson says there had generally been two lights – one telling us to stop and the other telling us to go. But William Potts, a Detroit police officer, found a way to make the lights safer.

“It was Potts’ inspiration to put in the third light, sort of amber caution, letting you know the signal change is imminent, so that you can prepare to slow down,” says Anderson.

Today, there are more than 3oo,000 intersections with traffic signals throughout the U.S.

And where was the first four-way traffic signal tower installed in the world?

It was at a corner of Woodward Avenue here in Detroit, says Anderson.

* Listen to the full interview with Matt Anderson above.

NOTE: An earlier version of this story put the number of intersections with traffic signals in the U.S. at more than 36,ooo. The correct number is more than 300,000.