WASHINGTON (AP) — Metro says weekend work on the red, orange, green and yellow lines will cause delays for train riders.

Metro says on the green line free shuttle buses will replace trains between Archives and Waterfront beginning Friday night and continuing through Sunday. Metro says customers using the shuttle bus service should add 20 minutes to their travel time.

In addition, on the yellow line, there will be no service between Fort Totten and Pentagon, leading to delays of 15 to 20 minutes for passengers using other lines to complete their trips.

Trains will also share a single track on portions of the red and orange lines. That may lead to delays of up to 20 minutes.