Updated at 6:22 a.m.
Metro said normal service has resumed between Stadium-Armory and Eastern Market after earlier single-tracking.
Original post at 5:49 a.m.
Metro said there are delays on the Blue and Orange lines Monday morning due to a signal problem outside of the Stadium-Armory stop.
Riders should expect delays in both directions.
Trains shared a track for less than 15 minutes.