Metro this morning announced plans to work on the Red, Blue, Orange and Green lines this weekend, requiring trains to share a track around the work zones from 10 p.m. Friday through the midnight closing on Sunday.

Metro anticipates this will delay many riders by 20 minutes, but the waits for trains can be longer, especially if you’re waiting to transfer trains.

Work is also scheduled for off-peak daytime and nighttime hours, but the transit authority says this should not have much effect on service, despite the single-tracking, because the trains don’t run as frequently anyway at these hours.

Weekend schedule

Red Line: Trains will share one track between Grosvenor and Twinbrook stations during platform repairs. Trains also will share a track between Takoma and Forest Glen while crews install cables and work on some station improvements.

Trains are scheduled to leave the ends of the line every 24 minutes. On Saturday and Sunday between 9 a.m. and 9 p.m., more trains will operate in the interior part of the line, between Grosvenor and Fort Totten. In that sector, trains should arrive at platforms about every 12 minutes.

Blue/Orange lines : Trains will share a track between Eastern Market and Stadium-Armory stations. Workers will be replacing rail fasteners.

Orange Line trains will share a track between Vienna and West Falls Church as workers replace cross ties and insulators. Blue Line trains will share a track between Franconia-Springfield and Van Dorn Street stations during the installation of new rails.

Orange Line trains will leave the ends of the line about every 20 minutes. Blue Line trains will operate between Largo Town Center and Van Dorn Streets. A shuttle train will operate between Van Dorn Street and Franconia-Springfield.

Blue Line trains and the shuttle train will leave their terminals about every 20 minutes.

Green Line: Trains will share a track between Southern Avenue and Naylor Road stations during replacement of rail fasteners.

Weekday schedule

Red Line: From 10 a.m. to 2 p.m. weekdays, trains will share a track between Shady Grove and Twinbrook during work on the rails and cross ties.

From 10 p.m. each night till the midnight closing Thursday, trains will share a track between Friendship Heights and Grosvenor. Crews will be working on the rails and on the tunnel leaks.

During the same night hours, trains will share a track between New York Avenue and Rhode Island Avenue stations. Crews will be working on the rails.

Blue Line: From 10 p.m. each night through Thursday, trains will share a track between the Stadium-Armory and Addison Road. Crews will be working on the slabs beneath the tracks.

Green Line: From 10 p.m. each night through Thursday, trains will share a track between Mount Vernon Square and Georgia Avenue/Petworth. Workers are preparing for a switch replacement.