7:30 A.M. Update:

Normal service has resumed on the Blue and Yellow Lines, according to Metro.

7:10 A.M. Update:

Single-tracking ended on the Blue and Yellow Lines at 6:53 a.m., according to Metro. Normal service has been restored, but you can expect residual delays to linger on both lines.

6:52 A.M. Update:

Trains are single-tracking between Arlington Cemetery and Pentagon City due to a switch malfunction outside of the Pentagon station.

6:42 A.M. Update:

Expect residual delays to continue in both directions on the Blue and Yellow lines. Delays stem from signal problems following overnight track work, according to Metro.

Original Post:

Blue and Yellow Line trains are single-tracking between L’Enfant Plaza, Pentagon City and Arlington Cemetery due to unscheduled track maintenance. There are delays in both directions on both lines.