A track problem near the Rosslyn Metro Station affected three Metrorail lines Friday morning.
The Orange Line single-tracked for a while between Foggy Bottom and Clarendon, causing delays in both directions. Single-tracking ended about noon.
The Silver Line ran only between Wiehle-Reston East and Ballston during the service disruption. Service to Largo was restored about noon.
Congestion from delayed Orange Line trains also caused delays on the Blue Line during the disruption.
Metro said it has reports of an arcing insulator but that has not been confirmed.