From WMATA:
“Metro announced travel alternatives to help customers plan for track work and maintenance over the Martin Luther King Jr. Day weekend that will close a portion of the Blue, Orange, and Silver lines on Friday, Jan. 12 through Monday, Jan. 15.
During the four-day closure, buses will replace trains with no rail service between Foggy Bottom-GWU and Arlington Cemetery on the Blue Line; and between Foggy Bottom-GWU and Clarendon on the Orange and Silver lines. The Rosslyn and Court House stations will be closed. Customers traveling through the work zone should expect significant delays and allow at least 30 minutes of additional travel time to account for shuttle buses.
Work crews will replace rail, rebuild concrete grout pads that support the rail, run fiber-optic cables, install platform edge lighting, and other maintenance activity. Without the closure, the work would have caused major disruptions over multiple weekends, as trains would single track every 26 minutes or with truncated service.”