Q
Why are stop signs red?
A
Why are stop signs red?
The first STOP sign appeared in 1915 in Detroit, Michigan. There were a variety of colors used for STOP signs until the late 1920s, when the background color was standardized for greater day and night visibility. Know what color this was? Not red – instead it was yellow! Actually, yellow was the color of STOP signs for almost 30 years!!!

After almost 30 years, in 1954, the STOP sign was changed to red. Why the change? There were several reasons:
Yellow is known for warning signs, therefore, the yellow STOP sign was not consistent with this.
Red traffic signals are use to signal vehicles to stop. 
So, the red STOP sign color is consistent with this.
Durable fade-resistant red coatings was finally available for signage.

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