Photo by Barbara.K.

It’s going to be a busy weekend around the District, but if you’re not clear about the aggressive maintenance schedule on the rails, you might find yourself arriving late to that Halloween party or, worse yet, Sunday’s Marine Corps Marathon.

In short, you’ll probably want to add plenty of time if you’re planning on using the Green, Orange or Red Lines. The Waterfront, Navy Yard, Anacostia and Congress Heights stations which serve Green Line trains will be closed all weekend, which means that riding that line — or the shuttle buses between those stations — may very well be the scariest experience of your Halloween weekend. (The Yellow Line, however, will still operate between Huntington and Greenbelt all weekend.) The Red Line will be single-tracking between Dupont Circle and Judiciary Square, and only every other train will run through that stretch of track, so we’d expect some crowded cars. Finally, Orange Line riders should brace for single-tracking between New Carrollton and Cheverly.

All the above work is slated to get underway at 10 p.m. tonight.

Now, if you’re planning on using Metro to get to the Marine Corps Marathon, Metro will be opening up early (at 5 a.m.) and running extra trains along the Blue Line between 5 to 9 a.m. and 11:30 a.m. to 3:30 p.m. to try and get runners and attendees to and from the Pentagon station.

And hey, on the bright side, at least Glenn Beck and Sarah Palin aren’t in town this year.