Part of me is assuming it was to do with the first traffic lights, but then I also feel like it’s probably older than that. Does it have something to do with military battalions perhaps?
In: Other
It’s purely down to culture, and specifically the American and British railroads. Track signals, when they began to use lights, used a white light for “Go” and a red light for “Stop”, it was believed that there was a good distinction between the two at a distance, and that red drew our attention.
Then one sad day, the red glass over the “stop” broke, and oh no… suddenly you just have two white lights. There was an accident, and after that it was decided to have two different colors, so if you saw a white light, you’d know it was broken and default to a stop. The color chosen was green, again because it’s highly visible to the human eye.
Red is an alarming color. It stands out. It’s the color of blood. It make sense to use it as a signal to stop since that could be a matter of life and death.
Ships (and now aircraft) have something called _navigation light_ — a red light on the left side, a green light on the right side.
Rules of the Sea say that if two ships are crossing paths, the one coming from the right has the right of way (Edit: That is very, very simplified, there are also rule about types of ships).
That is, if you see the green light on the right side of the other ship, you can go, if you see the red light on the left side of the other ship, you must give way.
Ever notice how when the lights are green some times you don’t even notice them? Red catches your eye even if you’re not 100% paying attention? In nature red is the color of danger: fire, blood, etc. Deep in our lizard brains we’re programmed to pay attention to the color red.
A fun bit of trivia… in Syracuse, New York there is one traffic light that has the green on top. The neighborhood was heavily Irish and when the traffic light was installed people bitched about the British color (red) being above the Irish one (green), so that’s the only light in the world where the green is on the top and red on the bottom.
Latest Answers