What type of signage indicates an upcoming restriction on airside roads?

Red signage is specifically designed to indicate restrictions and prohibitions on airside roads. This color is universally recognized as a signal for alertness and caution, conveying important information to drivers that they must adhere to specific rules or restrictions. For instance, red signs may indicate areas where vehicles are not permitted or where certain actions, like stopping or parking, are restricted.

In contrast, other colors serve different purposes; blue signage generally indicates information about services or facilities, green signage provides directional guidance, and yellow signage warns of potential hazards or advisories. Understanding these color-code conventions is crucial for ensuring safety and compliance while operating vehicles in airside areas.