 With a 1400-foot or longer approach light system, the minimum potential visibility might be reduced to 1/2 mile (2400 runway visual range), and the presence of touchdown zone and centerline lights with a suitable approach light system might further reduce the visibility to 3/8 mile (1800 feet runway visual range).The runway lighting is controlled by the air traffic control tower.At non-towered airports, pilot-controlled lighting may be installed that can be switched on by the pilot via radio.