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Standard traffic signals arrange red at top and green at bottom
Vertical light positioning assists colour-blind drivers across international roads
Vertical traffic signals position the red lamp at the top, amber in the middle, and green at the bottom. This uniform vertical arrangement helps colour-blind drivers identify signals by light position alone. The visual order was standardised internationally during the early twentieth century for road safety.
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Tags: traffic, safety, signals
Standard traffic signals arrange red at top and green at bottom: the short answers
- Where does this come from, and can I check it?
- Vertical light positioning assists colour-blind drivers across international roads. The figure is taken from Encyclopaedia Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
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