Updated at 10:25 a.m.
Metro said normal service has resumed on its Red Line.
Original post at 10:15 a.m.
Metro said riders should expect delays in both directions due to a signal problem outside Judiciary Square.
It was not immediately clear when the issue would be resolved.
Transit officials said ridership for the day was down compared to a normal weekday because the federal government and several area offices were closed because of the inclement weather.