Centerline lights make it easier for pilots to discern the centerline marking and maintain proper runway alignment during times of darkness or reduced visibility. The lights leading in the take-off or landing direction are variable white from the threshold to 900 m from the runway end; alternate red and variable white from 900 m to 300 m from the runway end; and red from 300 m to the end of the runway.
Definitions
Category I, II & III runways: Refers to a specific classification of runways based on their capability to support aircraft operations in low visibility conditions. CAT III runways are equipped with advanced instrument landing systems (ILS) and associated lighting systems to assist aircraft in landing safely when visibility is severely restricted, including during fog, heavy rain, or snow.