Link light rail is a light rail rapid transit system serving the Seattle metropolitan area in the U.S. state of Washington. It is managed by Sound Transit in partnership with local transit providers, and consists of two non-connected lines: Line 1 (formerly Central Link) in King County, which travels for between Seattle and Seattle–Tacoma International Airport; and Line T (formerly Tacoma Link) in Pierce County, which runs for under between Downtown Tacoma and Tacoma Dome Station. The system carries 24.1 million passengers annually, primarily on Line 1, and runs trains at frequencies of 6 to 24 minutes.