What happens when a vehicle operator encounters a stop bar that is lit?

When a vehicle operator encounters a stop bar that is lit, it is a clear indication that the operator must stop their vehicle and wait for permission to proceed. The illuminated stop bar serves as a crucial safety measure at airports, signaling to vehicle operators that they are at a point where entry onto an active runway or taxiway is prohibited or controlled. This prevents potential conflicts between vehicles and aircraft, thereby enhancing safety on the airside.

Waiting for permission before moving past a lit stop bar ensures that the operator is following established protocols to communicate with Air Traffic Control (ATC) or adhere to other ground traffic signals. This practice is essential for maintaining safe operations around active flight paths, where the movement of aircraft is critical to avoid accidents.