Because red light has lower CRI, causes confusion, and makes you sleepy.
- Lower CRI: Unlike white light, red light is monochrome light, so there are objects that cannot reflect the light. Then you cannot see them, which is dangerous for street lighting.
- Causing confusion: Since there are other lights, like the traffic lights, that are red, changing the street light to red will make other lights not obvious.
- Make you sleepy: People are not sensitive to red light. Besides, red light is often used in the bedroom because it increases melatonin secretion, so it will make you sleepy.