What is the primary purpose of "louvers" in traffic signals?

The primary purpose of louvers in traffic signals is to make the signal visible from a specific lane. Louvers are designed to block the light emitted from the signal in directions where visibility is not necessary, which helps to focus the light where it is needed most. This focused visibility enhances the effectiveness of the traffic signal for drivers in the designated lane, ensuring they can clearly see the signal status without interference from other traffic signals or light sources.

By directing the light effectively, louvers play a critical role in promoting safety at intersections by minimizing distractions and ensuring that drivers receive clear and accurate indications of traffic control. Their design contributes to a more efficient traffic flow and reduces the chances of accidents caused by ambiguous signal visibility.