Green Line (CTA)

The Green Line is part of the Chicago 'L' system, and is the only completely elevated route in the 'L' system. It utilizes the system's oldest segments (dating back to 1892), extending 20.695 mi (check infobox for time lengths) with 30 stops between Forest Park and Oak Park (Harlem/Lake), through Chicago's Loop, to the South Side and West Englewood (Ashland/63rd) and Woodlawn (Cottage Grove/63rd). As of September 2012, the average number weekday boardings on the Green Line is 70,554.

Lake Street Elevated
Beginning at the yard and inspection facilities in Forest Park, the Green Line runs east through Oak Park towards the city on an embankment parallel to Metra's Union Pacific/West Line tracks from the Harlem Avenue terminal (7200 W. - 400 N.), on the border of Oak Park and River Forest, to a point just west of Laramie Avenue. Here the Green Line tracks leaves the railroad embankment and continues east on a steel elevated structure directly above Lake Street, a major east-west thoroughfare. The 'L' bridges a couple of railroad tracks before entering downtown Chicago at Clinton Street. East of Clinton Street, the route bridges Metra's Union Pacific railroad tracks (which terminate just south of here at Ogilvie Transportation Center) and the Chicago River before joining the Union Loop 'L' tracks at Wells Street.

The Loop
In downtown Chicago, the Green Line operates over the famous Union Loop 'L' structure along with Brown Line (Ravenswood), Orange Line (Midway), Pink Line (Douglas), and Purple Line Express (weekday rush hours only) trains. However, Green Line trains operate both ways over the Lake Street and Wabash Avenue sides only, and does not use the Wells Street and Van Buren Street sides of the Loop.

The Green Line is the only line in the 'L' system that has multiple entry/exit points to the elevated Loop, the only route that does not use the Loop to terminate. Its route takes it over only the north and east portions of the Loop, which are used bidirectionally, as opposed to the Orange, Pink, Purple, and Brown Lines, which operate unidirectionally over the Loop and then return to their originating depots on one side of the city (West, Southwest, and North).

South Side Elevated
Leaving the Loop at Tower 12, the tracks continue along Wabash Avenue and follows an "S" curve (which was realigned in 2002) to the west and south now following the alley between Wabash Avenue and State Street to 40th Street. This 3.8 mile section is the oldest part of Chicago's 'L' system. On this segment, the Green Line shares tracks with the Orange Line between the Loop and 17th Street. Passengers can transfer between the two lines at Roosevelt/Wabash station. The only other station on this section is at 35th–Bronzeville–IIT (which is 2.5 miles south of Roosevelt/Wabash) adjacent the Illinois Institute of Technology campus and the Chicago Police Department Headquarters. At 40th Street, the route turns east to Indiana station, then turns south between Calumet and Prairie Avenues to the Garfield station and continues south to 59th Street where the route splits into two branches—the Englewood (Ashland/63rd) Branch and the Jackson Park (East 63rd) Branch.

Ashland Branch
The Ashland Branch continues south and west following 59th Street, Princeton Avenue and 63rd Street to the Ashland terminal (1600 W. - 6300 S.) in West Englewood. The yard and inspection shop lie to the south between the old Racine station and the Ashland/63rd terminal. The 'L' tracks continues west to a stub end at Hermitage Avenue, a prediction for a future extension of the route westward, however, those plans were cancelled in the late 1970s. Prior to 1992, the Englewood Branch had two additional stops at Wentworth and Harvard, closed by the CTA for service cuts. Halsted/63rd is the only remaining stop on the 3.1 mi route.

The Englewood Branch was permanently renamed the Ashland Branch as of March 2013 according to the CTA.

Jackson Park Branch
The Jackson Park Branch continues south from the mainline between Calumet and Prairie Avenues, passing the old yard and inspection facilities at 61st Street in Washington Park. South of here, the route curves east over 63rd Street and follows it to the current terminal at Cottage Grove/63rd (800 E. - 6300 S.). Prior to 1994, the Jackson Park Branch of the Green Line once terminated at University/63rd, and before that, at Stony Island/63rd from 1893 until 1982. In addition to losing the University/63rd station, the Jackson Park Branch also lost the 61st Street station and the 58th Street station in 1994.

Operating fleet
Currently, the Green Line is operated with the new Bombardier-built 5000-series cars. The 5000-series cars officially began running on the Green Line on July 1, 2012 after the Pink Line became fully re-equipped with the new cars. As additional 5000-series cars were assigned to the Green Line, the remaining Boeing-Vertol-built 2400-series cars were reassigned to the Red, Purple and Orange Lines to finish out their revenue service lives. Occasionally, Budd-built 2600-series rail cars and Morrison-Knudsen-built 3200-series rail cars were used on the Green Line, though these were loaned from the Blue, Brown and Orange Lines, and only when the Green Line was short on cars. With the 5000-series cars now completely equipping the Green Line fleet after the last of the 2400-series cars were reassigned in mid-May 2013, the borrowing of 2600-series cars and 3200-series cars is no longer necessary. Trains generally operate at 10 to 12 minute headways during much of the day (about 20 to 25 minutes on the Englewood and Jackson Park branches), with 4 to 6 car trains. There is no overnight service along the Green Line.

History
The Green Line operates over the two oldest sections of the Chicago 'L'. The South Side section started operation in 1892 when Chicago was preparing for the World's Columbian Exposition of 1893 in Jackson Park. The initial section was built to provide service between downtown Chicago and the exposition site. This first section of the Chicago and South Side Rapid Transit Railroad between Wabash Avenue and State Street went into service on June 6, 1892. It extended from Congress Street only as far south as 39th Street (Pershing Road). At that time a large part of the south side was little more than prairie, but by May 1, 1893, when the pioneer 'L' line was completed to Jackson Park, construction of homes, apartment buildings and commercial properties was booming in the area.

Continued expansion of the area development was reflected in construction of the Englewood, Normal Park, Kenwood and Stock Yards branches of the South Side 'L' between 1905 and 1908. Of these, only the Englewood and Jackson Park branches remain: because of insufficient patronage, the Normal Park, Stock Yards and Kenwood branches were closed in the 1950s. The Lake Street Elevated was Chicago's second rapid transit line. It began operation from a terminal at Madison and Market streets to Lake Street and California Avenue on November 6, 1893. The line was gradually extended westward to Laramie Avenue on April 29, 1894; to Austin Avenue on April 15, 1899; to Wisconsin Avenue, Oak Park using street railway trackage on May 15, 1899 (closed in 1902), and to Marengo Avenue, Forest Park, on May 14, 1910.

The construction of the Lake Street Elevated led to a political quarrel in suburban Cicero Township, which at the time included Oak Park and Austin. In 1898, Austinites, having a majority on Cicero's town council, used political influence to allow the extension of the Lake Street line from the city border at Laramie Avenue (then called 52nd Avenue) into their community. This infuriated other Cicero Township residents, who retaliated the following year by holding a joint election to force Austin's annexation to the City of Chicago. Much to the dismay of local residents, this effort succeeded, and Austin became part of Chicago in 1899. A century later, Oak Park commuters, who had come to depend on the service, were among the most vocal critics of the Green Line's closure for rehabilitation.

From 1949 until 1993, the Englewood and Jackson Park branches were part of the North-South Route in various service configurations operating from the north side through the Loop, and to the south side. On October 17, 1943, the Englewood and Jackson Park services were rerouted into the State Street Subway to provide improved crosstown access through the heart of city and to alleviate congestion on the over-crowded Union Loop Elevated. On July 31, 1949, during the North-South rapid transit service revision by the CTA, the Howard-Englewood/Jackson Park route was created, operating via the State Street Subway, using the 13th street portal.

On May 6, 1969, the Englewood branch was extended to the current south terminal at Ashland/63rd. On December 12, 1982, the Jackson Park branch was shortened to University because of structural deterioration at the Dorchester Bridge which carried the route across the Illinois Central Railroad to the former Stony Island/63rd terminal which closed on March 4, 1982, and was later demolished.

The Lake Street 'L' would remain largely unchanged until 1948, when a number of its historic passenger stations were closed and demolished in an attempt to promote the "A" and "B" skip-stop express train service (discontinued on the Green Line upon its reconfiguration in 1993). On October 28, 1962, the western two and one-half mile section of the line which operated at street level was elevated along the Chicago and Northwestern Railroad right-of-way opening new above-ground stops at Central, Austin, Ridgeland, Oak Park and Harlem/Lake, Forest Park. On September 28, 1969, the Lake Street branch was paired with the new Dan Ryan Line to form the West-South Route, operating from Forest Park through downtown via the Union Loop 'L' to 95th/Dan Ryan. The Lake-Dan Ryan routing was to fulfill the service implementation outlined in the 1968 Chicago Central Area Transit Plan. However, when that controversial subway project was cancelled in 1979, Lake-Dan Ryan service remained and lasted for 24 years.

On February 21, 1993, the south side sections of the North-South and West-South routes were switched south of Roosevelt Road, creating the current Red Line (Howard-Dan Ryan) and the Green Line (Lake-Englewood/Jackson Park)

On January 9, 1994, the Green Line closed for the largest transit rehabilitation project in the city's history. The Green Line reopened on May 12, 1996, with much of the renewal work completed, and with the exception of a few stations. Six stations were closed indefinitely following the rehabilitation project, which angered many commuters who depend on the Green Line. In September 1997, after political pressure brought on by community leaders, the Jackson Park branch was shortened again from University to Cottage Grove after previous attempts by the City, CTA and other agencies to extend the route eastward to Dorchester, immediately west of the Illinois Central Railroad. This had seemed logical to the pro-"Dorchester Terminal," camp, due to the fact that the Metra Electric District and South Shore Line both share a station along the IC ROW, at 63rd Street.

On April 26, 1998, the Green Line, like the Purple Line and the Douglas branch of the Blue Line lost its 24 hour service due to budget shortfalls and operates only between the hours of 4 a.m. and 1 a.m weekdays. The Green Line runs 6 a.m. Saturdays and 6:30 a.m. on Sundays

Incidents
On May 28, 2008, a derailment was reported, with approximately 24 injuries. Two train cars on the four-car train appeared to be derailed, with the leading car abutting the one behind it at an angle of approximately 150 degrees. The train cars were separated at a switching point near 59th Street.

Points of interest
The Green Line provides access to, among other destinations, the Garfield Park Conservatory (Conservatory-Central Park Drive), United Center (Ashland) James R. Thompson Center, Richard J. Daley Center and City Hall-Cook County Building (Clark/Lake), Millennium Park (Randolph/Wabash and Madison/Wabash), the Art Institute of Chicago (Adams/Wabash), the Auditorium Building of Roosevelt University, Museum Campus and Soldier Field (Roosevelt/Wabash), the Illinois Institute of Technology and U.S. Cellular Field (White Sox Park) (35th–Bronzeville–IIT), the University of Chicago (Garfield) and Kennedy-King College (Halsted/63rd). The Clinton/Lake and Randolph/Wabash stops are useful for reaching Metra and South Shore Line trains at the Ogilvie Transportation Center and Millennium Station.