What is the primary purpose of runway edge lights?

The primary purpose of runway edge lights is to define the edges of the runway. These lights are essential for providing visual guidance to pilots as they approach and land on the runway, especially during low visibility conditions such as nighttime or adverse weather. The edge lights are typically white and are positioned along the sides of the runway, helping to delineate the usable area and ensuring that pilots can safely identify the boundaries of the runway. By clearly marking the edges, they help prevent runway excursions and enhance overall safety during takeoff and landing operations.