6:14 p.m. Update: Metro says normal service has resumed on the Green Line.
5:48 p.m. Update: Metro says trains are no longer single-tracking.
Original post: Metro is single-tracking trains on the Yellow and Blue lines due to a switch problem at King Street Station, a problem that has repercussions through much of the system.
Blue Line trains are single-tracking between Braddock Road and Van Dorn Street stations. Yellow Line trains are single-tracking between Braddock Road and Huntington.
Metro said that Green Line trains are also affected between L’Enfant Plaza and Fort Totten because they share tracks with the Yellow Line along that segment.
Metro said crews plan to manually operate the switch.