Did you know this? The first traffic signals were designed for trains, not cars. They were red and green, powered by gas, and could be a little dangerous in the event of a leak.
Red is a symbol inherited from the railways!
Red symbolizes danger in many cultures. This color was chosen considering that any color in the visible spectrum has the longest wavelength. You can see it from a greater distance than other colors.
Green originally meant “attention”!
The role of green in light has actually changed dramatically over time. The wavelength is shorter next to yellows in the visible spectrum. It is easier to see than any color other than red and yellow. In the early days of the railroad lights, green actually meant “attention”.
Yellow means “attention”!
From the first driving days until the mid-1900s, not all stop signs were red. Most of them were yellow. Because at night it was almost impossible to see a red stop sign in a poorly lit area. The yellow becoming a stop sign began in Detroit in 1915.
As materials and technologies develop; red was able to maintain its natural place in the sign hierarchy. And yellow, which is still quite visible due to this situation, took the 2nd place in traffic lights. Yellow after red in terms of visible wavelength; today it is used for school grounds, buses, pedestrian crossings and other important warnings.
Ecem Sena Celik
