Photo by parapluiesdoux.It’s kind of a misnomer, seeing as how on any given day and depending on what’s happening around the District, any Metrorail station could be the “busiest” in the system. Regardless, the Washington Business Journal reports that based on average weekday ridership in May, Union Station comes out on top — the station handled 32,745 riders per day on average. Not surprisingly, Metro Center, Gallery-Place-Chinatown, Farragut North and Farragut West round out the top five. The least busy station: Friendship Heights, which only saw 9,804 riders per day. The big surprise of the May numbers is Columbia Heights, which, despite the lure of DCUSA, only ranked 19th. Then again, maybe we shouldn’t be surprised — Columbia Heights ranked as the system’s least busy station in 2008. Add in the fact that the neighborhood is well-served by buses and easy to bike or walk to and from, and the station’s relatively low ridership isn’t such a shock.