<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by EricH:
As a current DC resident, I'd change the cab-at-night suggestion. Off-hours Metro ridership has really increased in the last few years and they've increased train frequencies along with it. This past Monday night at 9:30 the Red Line was running every ten minutes.</font>
Just note than Monday to Thursday night, the last train cut-off can be as early as 11:20 p.m. or 40 minutes earlier than you expect if you presume a midnight on weekdays, and 2 a.m. on weekends (not sunday night) cut-off. Just a note of caution.