The Loop (historically Union Loop) is the long circuit of elevated rail that forms the hub of the Chicago "L" system in the United States. As of 2012, the branch has served 74,651 passengers every weekday. The Loop is so named because the elevated tracks loop around a rectangle formed by Lake Street (north side), Wabash Avenue (east), Van Buren Street (south), and Wells Street (west). The railway loop has given its name to Chicago's downtown, which is also known as the Loop.