system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what is the purpose of the horizontal shutters on green traffic lights?
gpt
So you don't mistake a nearby traffic light that's green for the light that applies to you when there is one closer that's red. Around here they are common when there is a fire station just a few hundred feet from an intersection, the light in front of the fire station is [almost] always green, but there is a light at the corner of the fire station as well for an intersection. The blinds cover up the green light before you enter the intersection, so you can only see the light for the intersection when approaching it, when you enter the intersection and get near the fire station you can then see the green in front of the fire station.

The red and yellow never has blinds so you can always see if the light is red. Also sometimes they use lenses on the green instead of blinds (they have the same effect)