In airport lighting, what is the primary indication of blue lights?

The primary indication of blue lights in airport lighting is the outline of taxiways. Blue lights are specifically designed to mark the edges of taxiways, helping pilots navigate safely while taxiing on the ground. This visual guidance is particularly critical during night operations and in low visibility conditions, as it clearly delineates the taxiway path separate from other areas, such as runways or non-movement areas.

Understanding the purpose of blue lighting enhances situational awareness for pilots and ground personnel, reducing the risk of accidents and ensuring smooth operations at the airport. The use of blue lights purely for taxiway delineation is standardized, which aids in maintaining consistency across different airports.

Other options, while relevant to airport operations, do not align with the established color-coding for airport lighting. For instance, runway borders are typically marked with white lights, while emergency access routes and fly zones may have different specifications not associated with the blue light signal.