Continuing track work will cause delays through the weekend on Metrorail.
It starts Friday night at 10 p.m., with Green Line trains sharing a single track between the Southern Avenue and Naylor Road stations while Metro crews replace rail fasteners.
Similar work will cause delays on the Blue and Orange lines between Eastern Market and Stadium Armory. A separate shuttle train will operate on a single track between the Franconia-Springfield and Van Dorn stations. Orange Line trains will share a track between Vienna and West Falls Church.
On the Red Line, repairs will have trains sharing a single track between Grosvenor and Twinbrook and also between Takoma and Forest Glen.
Metro said to expect delays of at least 20 minutes.
Things should be back to normal Monday morning.