Traffic Lights. Who Knew?

Fun fact: The first three-colored traffic lights were installed in 1920. No one seems to have written down the exact day that these ubiquitous devices arrived on the scene, but it was sometime before October, at the intersection of Michigan and Woodward Avenues in Detroit. Happy 100^th birthday sometime before October, traffic light! You’ve been annoying commuters ever since!

Actually, according to Wikipedia,

“The world’s first traffic light was a manually operated gas-lit signal installed in London in December 1868. It exploded less than a month after it was implemented, injuring its policeman operator. Earnest Sirrine from Chicago patented the first automated traffic control system in 1910. It used the words “STOP” and “PROCEED”, although neither word was illuminated.”

But the one the majority of us see today (and every other day of our lives, like it or not) is 100 years old. Before traffic lights, humans were placed at intersections to direct traffic. What could possibly go wrong? I can’t imagine a more tedious or more irritating job on earth, and this is coming from someone who opens drawbridges for a living.

Between the exploding gas light and our current tried and true one, several designs were tried out throughout the world, some with semaphore flags, which weren’t particularly effective at night. No two were alike, it seems, and that must have caused no end of confusion. I’m impressed that society survived.

The idea to control multiple intersections at once, and do so automatically, didn’t come about until March, 1922, in Houston, Texas. Traffic lights were not introduced to South India until 1953, and it seems they’ve been ignored ever since.

I also happen to know from personal experience working with the Department of Transportation that while most lights used to be encircled in black tubes to reduce glare and increase visibility, most locations have gotten away from that because birds would use them as nesting sites and block the light. Now if anything, most lights have a shade cover across the top for glare reduction and to reduce water intrusion.

While doing research for this post, I came across this article that discusses why the colors red, green and yellow were chosen for traffic lights. Basically, red is the color with the longest wavelength, so it can be seen from a greater distance than other colors. It was used to indicate danger long before traffic signals became a thing.

There’s no indication as to why green has been used for Go. Blue is on the opposite side of the color wheel from Red, and that’s the color Japan used for many years, but the rest of the world hopped on the Green bandwagon. Yellow was chosen because it has a shorter wavelength than red, but not as short as green.

So there you have it. Everything you ever wanted to know about traffic lights but were afraid to ask. You’re welcome.

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Author: The View from a Drawbridge

I have been a bridgetender since 2001, and gives me plenty of time to think and observe the world. View all posts by The View from a Drawbridge