Metro warned riders on the Blue and Orange lines of delays during the Thursday night rush.
By 6:10 p.m., track repairs near the Stadium-Armory Metro Station were completed and trains resumed running on two track, according to Metro.
But several riders tweeted about overcrowded trains and delays longer than the 20-30 minutes Metro had warned about. Residual delays of about 10 minutes were expected as regular service resumed.
For several hours, trains single-tracked between the Eastern Market and Stadium-Armory stations. Metro deployed additional workers to assist and inform riders.
Metro crews replaced a broken track part at the junction where the Blue and Orange lines diverge east of Stadium-Armory -- one of the busiest switching points in the Metrorail system.