All construction sites adjacent to active aircraft movement areas shall be delineated and lighted with which type of lights?

• A. White obstruction lights
• B. Green obstruction lights
• C. Amber obstruction lights
• D. Red obstruction lights

Answer: (D)

Hazards near active aircraft movement areas must be clearly identified and lit so pilots can see and avoid them. Red obstruction lights are the standard choice for marking temporary obstacles adjacent to runways and taxiways, because the color universally signals a hazard to aircraft and provides a persistent, highly visible cue at night and in poor visibility. White, green, or amber lights are used for other parts of airport lighting systems and do not convey the same obstacle warning near movement areas, so they aren’t appropriate for marking construction sites in this context.