Why did they choose the colour of the traffic lights?

Question

why green red and yellow

Answer 1

Apparently the colors of red and green were standard in the electrical industry at the time. The makers of railroad signals and traffic lights simply adopted the familiar color scheme.

Red-generally symbolizes danger or warning, making it a good choice for "stop."

Green-is calming to us, probably because it is prolific in nature and a sign of health and abundance, so it might have lent itself to mean "go."

Yellow-or amber, is associated with warmth, happiness, and the sun. Despite these connotations, it was chosen to symbolize "caution." Perhaps because it contrasts well with green and red, and is highly visible without being too harsh on the eyes of motorists. Today, yellow is commonly used as a warning symbol for both traffic signs and alert systems.

Answer 2

can only answer for the red, since it is the color that travels the most distance, therefore is the one the human eye can see from further away. Since stopping is the most important to prevent an accident. Red was chosen.

Answer 3

Asked and answered very well here. http://ask.yahoo.com/ask/20031023.html

Bottom line, blame the railroads, who had the colors standardized and the automobile borrowed from them.

Added: Red is not the color seen the most distance, that quality belongs to blue.

Answer 4

THE PLACEMENT HOWEVER IS FOR THE COLOR BLIND.ie red-top, amber-middle, green-bottom