The Loop (CTA)

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" system in Chicago, Illinois.

The Loop
The southeastern corner of The Loop
Overview
Status	Operational
Locale	Chicago, Illinois, USA
Stations	8
Service
Type	Rapid transit
System	Chicago "L"
Services	Orange Line   Green Line   Purple Line Express   Brown Line   Pink Line
Operator(s)	Chicago Transit Authority
Daily ridership	74,148 (average weekday 2016)[1]
History
Opened	1895–1897
Technical
Track length	1.79 miles (2.9 km)
Number of tracks	2
Character	Elevated
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Minimum radius	90 feet (27 m)
Electrification	Third rail, 600v DC

As of 2012, the branch has served 74,651 passengers every weekday.^[2]

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.^[3] However, transportation historian Bruce Moffat has concluded that "The Loop" was not used as a proper noun until after Charles Yerkes' 1895–97 construction of the elevated structure.^[4]