We mentioned it earlier this week, but it's worth a reminder: Metro is shutting down the Yellow line rail bridge over the Potomac River this weekend to do track maintenance and conduct an annual bridge inspection. This means that the Yellow line will operate only between Huntington and Arlington Cemetery starting tonight at 10 p.m. through Sunday at midnight. You read that right -- there will be no Yellow line service between the Pentagon and Fort Totten stations all weekend, so Yellow line (and Green, for that matter) customers should expect delays of at least 20 minutes, and anyone traveling south of the Pentagon should take the Blue Line if possible.