High Quality Content by WIKIPEDIA articles! Central Link is a light rail line running between downtown Seattle and Seattle-Tacoma International Airport. It is the initial phase of Sound Transit`s Link Light Rail system. Service operates seven days a week, from 5 am to 1 am Monday through Saturday and from 6 am to midnight on Sundays. Trains are composed of two cars, each with a capacity of 200 passengers—74 seated and 126 standing. Opened on July 18, 2009, Central Link initially operated between downtown Seattle and Tukwila, on a 13.9-mile (22.4 km) route. Service was extended by 1.7 miles (2.7 km) from Tukwila to SeaTac Airport on December 19, 2009.