Single-tracking on several sections of Metro will cause delays of up to 30 minutes in some spots starting Friday night.
The work will last from late Friday through the closing of the system on Sunday.
On the Red line, trains will single-track between Dupont Circle and Judiciary Square while repairs at Farragut North are made.
On the Blue/Orange line, 20 minute delays will occur between Stadium-Armory and Eastern Market. On the western side of the Orange line, trains will share a track between Vienna and West Falls Church.
The Green line will share a track between Greenbelt and College Park.