What do burning red obstruction lights indicate?

Burning red obstruction lights indicate a hazard. These lights are designed to alert pilots, drivers, and ground personnel to obstacles that could pose a threat while navigating an area, particularly in low-visibility situations or at night. The presence of these lights is essential for maintaining safety and ensuring that individuals are cautious around these potential dangers.

The options relate to the visibility and guidance systems at airports, but burning red obstruction lights specifically serve the purpose of warning about hazards, rather than denoting safe conditions, taxi routes, or visibility limitations. Understanding this function is crucial for ensuring safety around the airport environment and for all who operate in or around potentially obstructive structures.