"The Dulles Corridor Metrorail Project involves the design and construction of a 23.1 mile extension of the existing 103 mile long Washington Metropolitan Area Transit Authority (WMATA) rail system. The improvements will extend the existing Orange Line from the transit station at West Falls Church in Fairfax County, Virginia, to the western terminus at Ashburn (State Route 772) in Loudoun County, Virginia. Phase 1 is known as the Extension to Wiehle Avenue and comprises the initial 11.6 mile extension. Phase 2 is known as the Extension to Dulles Airport/Route 772."--Introduction, leaf 3.