When are blank-out signs only activated?

Blank-out signs are activated during specific times of day and specific events to effectively communicate important information to drivers without using constant illumination. This selective activation helps in conserving energy and minimizing unnecessary distractions for drivers when the signs are not needed, such as during off-peak hours or when there are no events that would require the sign's message to be displayed.

The functionality of blank-out signs is intended to convey crucial real-time information, such as regulatory messages or warnings that are pertinent to current traffic conditions. By activating these signs only during defined time frames or in response to certain events—like road closures, detours, or special circumstances—the system ensures that drivers receive relevant guidance when it matters most. This increases safety and compliance while also maintaining the sustainability of the traffic management system.

Other choices may imply constant or unnecessary activation, which does not align with the operational philosophy behind blank-out signage.