The Loop (historically Union Loop, or commonly Loop) is the 1.79-mile (2.88 km) long circuit of elevated railroad that forms the hub of the Chicago 'L' rapid transit system in Chicago, Illinois. As of 2012, the branch has served 74,651 passengers every weekday. The Loop is so named because the railroad loops around a rectangle formed by Lake Street (north side), Wabash Avenue (east), Van Buren Street (south), and Wells Street (west). The railroad loop has given its name to Chicago's downtown, which is known as the Loop. Numerous accounts assert that the use of this term predates the elevated railroad, deriving from the multiple cable car turntables, or loops, that terminated in the district, and especially those of two lines that shared a loop, constructed in 1882, bounded by Madison, Wabash, State, and Lake.