As part of the ongoing project to improve the main runway at Reagan National Airport, construction crews will make modifications to the runway’s approach light system. Many of the lights are located on a pier in the Potomac River, immediately south of the main runway (also known as Runway 1-19). The initial pier work will require overnight pile driving to avoid interfering with the daily schedule of flights. The lights will be replaced with upgraded, new equipment. The overnight pier work will coincide with runway milling and paving on the airfield.