From WMATA and Prince of Petworth blog:
Metro is giving customers additional notice about an upcoming weekend track work project that will result in buses replacing Red Line trains through Downtown DC over the weekend of September 7-9.
The major Red Line project will begin at 10 p.m. Friday, September 7, and continue through system closing on Sunday, September 9. During this time, buses will replace Red Line trains between Dupont Circle and NoMa-Gallaudet U stations to allow for installation of new fiber optic cable for improved wireless communications, as well as track maintenance and third rail upgrades.
The following stations will be affected:
Dupont Circle – open for rail service to/from Shady Grove only
Farragut North – closed
Metro Center – open for Blue/Orange line only
Gallery Place – open for Green/Yellow line only
Judiciary Square – closed
Union Station – closed
NoMa-Gallaudet U – open for rail service to/from Glenmont only
Free shuttle bus service will operate on two routes:
Limited stop buses will operate between Dupont Circle, Metro Center, Gallery Place and NoMa-Gallaudet U stations only. Customers using limited stop buses should allow up to 30 minutes of additional travel time.
Local buses will stop at all stations. Customers using local bus service should allow up to 50 minutes of additional travel time.