Kritika Handa

⁠Why Are Traffic Lights Red, Yellow And Green?

Red, yellow, and green correspond to peak sensitivity ranges in the human eye, making them most effective for visibility and differentiation under daylight conditions.

Photopic Vision

The chosen colors have optimal visibility at night. Red and green are easily distinguishable in darkness, reducing accidents and improving road safety.

Nighttime Visibility

Red, yellow, and green are highly visible and distinct from one another, ensuring clarity in diverse lighting conditions and from long distances.

Colour Visibility

These colors are spaced far apart in the visible spectrum, minimizing confusion and overlap in human vision, essential for quick and accurate signal interpretation.

Colour Spectrum

Red universally means "stop," green means "go," and yellow means "caution," creating a standardized and intuitive system for drivers worldwide.

Colour Association

Red is stimulating and attention-grabbing, yellow is alerting and cautionary, and green is calming and reassuring, aligning with their traffic functions.

Colour Psychology