What is the primary purpose of runway centreline lighting?

The primary purpose of runway centreline lighting is to facilitate landing when visibility is obscured. These lighting systems are strategically placed along the runway centerline and provide crucial visual guidance to pilots during approach and landing, particularly in low visibility conditions such as fog or heavy rain. The lights help ensure that pilots can maintain proper alignment with the runway during critical phases of flight, thereby enhancing safety and reducing the risk of accidents.

Other options might involve aspects of runway operation, but they do not address the specific role of centreline lighting. For instance, while providing illumination for takeoff might be a function of general runway lighting, the centreline lighting specifically aids in guidance and alignment during landings, which is particularly vital in poor visibility. Similarly, identifying taxiway intersections and signaling runway closures involve different types of lighting or signage that serve separate operational purposes.