A comprehensive inspection of Metro's 5000-series rail cars after last week's incident on the Blue Line found no new issues with train equipment, WMATA says.
The investigation continues into the Dec. 20 incident, during which a friction ring fell off the brake mechanism of a Blue Line train at the L'Enfant Plaza station.
Two trains hit the piece of brake, causing multiple strains to be stranded. Hundreds of people had to be evacuated from stuck trains between L'Enfant Plaza and the Smithsonian Station.
Officials are still working to determine a root cause for the accident, in which no one was seriously injured.
The Blue and Orange Lines were shut down for several hours in the wake of the incident.