Proposed expansion of the Chicago "L"

Since the inception of the Chicago "L" in 1892, various planning organizations have developed master plans to expand or reorganize the "L". Throughout the mid-20th century, plans were made to demolish the Loop Elevated for a series of downtown subway lines. Since its creation in 1955, the Chicago Area Transportation Study (CATS), now the Chicago Metropolitan Agency for Planning (CMAP) after the 2006 merger, has developed transportation plans spanning the Chicago metropolitan area, such as public transit expansions.

Early 20th century plans The Burnham Plan of Chicago in 1909 conceived many urban planning proposals to improve Chicago's infrastructure and quality of life. Among other proposals, the Burnham Plan recommended expanding the city's rapid transit system through subway and elevated lines, but the plan offered little details on each of the proposed routes.

On May 9, 1911, a municipal subway commission was established by Peter Reinberg, the alderman who chaired the Committee on Local Transportation, at the request of Mayor Carter Harrison IV. Subsequently, the Joint Report on Comprehensive System of Passenger Subways for the City of Chicago, published on September 10, 1912, by the Harbor and Subway Commission, was the first municipal plan to develop underground subway lines in Chicago. A similar municipal commission established in 1915, the Traction and Subway Commission, proposed a general expansion of the Chicago "L", including the development of subway lines, and the municipalization of the "L". The recommendations from the 1915 commission culminated in the Report of the Chicago Traction and Subway Commission in 1916.

In response to growing transportation demand, Rudolph F. Kelker, Jr., an engineer working with the Committee on Local Transportation, published the Report and Recommendations on a Physical Plan for a Unified Transportation System for the City of Chicago in 1923. The plan was larger in scope than the previous plans, proposing the unification of urban transit systems (rapid transit and on-street transit) alongside the addition of new subway and elevated lines.

Similar aspirations were present in two subsequent plans in 1927 and 1930.

A Comprehensive Local Transportation Plan for the City of Chicago was published in 1937 in response to the Great Depression and the growing number of automobile registrations. The plan proposed a subway line under State Street as well as the demolition of the Loop Elevated. The plan also proposed replacing elevated lines (Douglas Park, Lake Street, and Logan Square branches) with elevated highways and replacing "L" stations on these lines with bus stations.

1939 Comprehensive Plan

The Chicago Department of Subways and Superhighways published the Comprehensive Plan for the Extension of the Subway System of the City of Chicago in 1939. Much like the 1937 plan, the 1939 plan proposed replacing the Loop Elevated with a series of underground lines. The plan was divided into four stages.

Initial System of Subways (First Stage) In 1937, the City of Chicago applied for federal loan and grant from the Public Works Administration (PWA) for the construction of the State Street subway as well as two east–west underground streetcar lines. However, Harold L. Ickes, the director of the PWA, rejected the streetcar lines in favor of a second rapid transit subway line. The city ultimately caved in to Ickes's demand. In 1938, federal approval was given to fund the city's Initial System of Subways, which comprised the State Street subway and the Milwaukee–Dearborn subway.

By the time the 1939 plan was published, the first stage was reserved for the Initial System of Subways.

State Street subway , $25.75 million The subway line was planned to run below Clybourn Avenue, Division Street, and State Street. Construction began on December 17, 1938, and the line opened on October 17, 1943. Milwaukee–Dearborn subway , $19.85 million The subway line was planned to run below Milwaukee Avenue, Lake Street, Dearborn Street, and Congress Street from Evergreen Avenue to LaSalle Street. Construction began in March 1939, but work was suspended between 1942 and 1945 due to material rationing during World War II. Construction resumed in 1945, and the line opened on February 25, 1951.

Subsequent stages Beyond First Stage, lines in each successive stage were given lower priority and urgency. The Loop Elevated would have been dismantled after the Second and Third stages. A series of east–west streetcar lines along downtown surface streets would have also been dismantled after the Second Stage.

LineRoadsFromToRoute milesCost (1939)Notes Second StageCongress Street subwayCongress StreetMetropolitan main line near Halsted StreetDearborn subway at LaSalle Street$7.3 millionSubway; later became the West Side Subway (see )Lake Street subwayLake StreetLake Street Elevated near Racine AvenueDearborn subway$4.4 millionSubwayWashington Street subwayWashington StreetClinton StreetTerminal loop east of Michigan Avenue$5.4 millionStreetcar subway; the line would incorporate the Washington Street TunnelJackson Street subwayJackson BoulevardClinton StreetTerminal loop east of Michigan Avenue$6.3 millionStreetcar subway; the line would incorporate the Van Buren Street Tunnel Third StageWells–Archer–Ashland subwayWells Street, Archer Avenue, and Ashland AvenueNorth Side main line north of Chicago Avenue79th Street at Ashland Avenue$59.2 millionSubway14th Street Connection14th Street and State StreetWells Street subway at 14th StreetState Street subway south of Roosevelt Road$3.6 millionSubwayMilwaukee Avenue subway extensionMilwaukee AvenueFoster Avenue at Milwaukee AvenueLogan Square branch near Logan Square station$22.2 millionSubwayDouglas Park subwayBlue Island AvenueDouglas branch near Wood StreetCongress Street subway near Desplaines Street$11.0 millionSubway Fourth StageSouth Park Avenue subwaySouth Park AvenueJackson Park branch west of South Park Avenue79th Street at South Park Avenue$10.1 millionSubwayArcher–Cicero subwayArcher Avenue and Cicero Avenue63rd Street at Cicero AvenueWells–Archer–Ashland subway at Ashland Avenue$29.6 millionSubwayNorth Avenue subwayNorth AvenueCentral Avenue at North AvenueHumboldt Park branch at Lawndale Avenue$15.9 millionSubwayBelmont Avenue subwayBelmont AvenueOak Park Avenue at Belmont AvenueMilwaukee Avenue subway extension at Belmont Avenue$17.3 millionSubwayMilwaukee Avenue express subwayMilwaukee AvenueMilwaukee Avenue subway extension at Logan SquareMilwaukee–Dearborn subway at Ashland Avenue and Division Street$6.2 millionSubwayCrosstown subwaysRavenswood branch near Roscoe StreetAshland Avenue subway at Archer Avenue$21.2 millionSubway; would incorporate the north–south segments of the Douglas and Logan Square branchesMichigan Avenue subwayMichigan AvenueRandolph Street at Michigan AvenueVan Buren Street at Michigan Avenue$1.7 millionStreetcar subwaySources:

New Horizons plan (1958) The Chicago Transit Authority (CTA) published the New Horizons for Chicago's Metropolitan Area in January 1958. The 20-year plan was anticipated to cost $315 million (equivalent to $ billion in ).

Proposed extensions One of the lines listed in the New Horizons plan was the West Side Subway, a rapid transit line that would run along the Congress Expressway. The line was intended to replace the Garfield Park branch. Construction on the expressway, which accompanied the transit line, began in 1949. The initial section of the line opened on June 22, 1958, and the final section opened on March 20, 1960.

Two additional lines that were eventually built in principle were the Northwest Rapid Transit and the South Side Rapid Transit.

The Northwest Rapid Transit was planned to branch north from the Logan Square branch along the previous alignment of the proposed Crosstown Expressway between Talman Avenue and Rockwell Street. The line would then run northwest along the median of the Northwest Expressway from Talman Avenue to the city limit of Chicago, with an eventual extension to O'Hare International Airport. The line opened to on February 1, 1970, but the north–south section was routed below Kimball Avenue. On February 27, 1983, the line was extended to River Road; on September 3, 1984, the line was further extended to O'Hare station in the eponymous airport.

The South Side Rapid Transit was planned to travel along the median of the South Expressway between 30th and 95th streets. South of 95th Street, the line would be divided into two branches: the eastern branch to 103rd Street along the Calumet Expressway and the western branch to 119th Street along today's I-57. A connector ramp to the Englewood branch at 59th Street was also proposed. The line opened on September 28, 1969, but the connector ramp and the segments south of 95th Street were not built.

LineRoadsFromToCost (1958)NotesWest Side SubwayCongress ExpresswayDesplaines AvenueMilwaukee–Dearborn subway at LaSalle Street$27.00 millionExpressway-median lineNorthwest Rapid TransitNorthwest ExpresswayCanfield AvenueLogan Square branch between Talman Avenue and Rockwell Street$31.00 millionExpressway-median lineSouth Side Rapid TransitSouth Expressway, Calumet Expressway, and today's I-57State Street and Wells Street subways119th Street (Blue Island branch) 103rd Street and Doty Avenue (Calumet branch)$31.75 millionExpressway-median lineSouthwest Rapid TransitSouthwest ExpresswayCicero AvenueHalsted Street$7.00 millionExpressway-median bus rapid transit lineWells Street SubwayWells StreetNorth Side main line north of Chicago AvenueSouth Side Rapid Transit$25.00 millionSubwayJackson Boulevard SubwayJackson BoulevardWest Side Subway near Halsted StreetTerminal loop east of Michigan Avenue$20.00 millionSubwayWashington Street SubwayWashington StreetCanal StreetMichigan Avenue$15.00 millionUnderground bus rapid transit lineLake Street Routing via West Side SubwayBelt Railway of ChicagoLake Street ElevatedWest Side Subway$3.50 millionEnglewood Clearing Extension63rd StreetCicero AvenueEnglewood branch at Loomis Street$20.50 millionCalifornia–Western Rapid TransitCrosstown Expressway (proposed)Northwest Rapid TransitEnglewood Clearing Extension$14.00 millionExpressway-median line Sources:

Proposed modernizations The New Horizons plan also proposed modernizations of transit infrastructure. Under the plan, signaling control systems would be expanded to uncovered areas ($28.00 million), 31 sharp curves would be straightened ($6.40 million), and 27 substations would be automated ($23.1525 million). The plan additionally called for the grade separation of the at-grade segments of the Douglas Park branch ($20.00 million), the Lake Street Elevated ($4.00 million), and the Ravenswood branch ($4.75 million). The Douglas Park branch was also planned to be extended to Harlem Avenue. Ultimately, only the grade separation of the Lake Street Elevated (between Harlem Avenue and Laramie Avenue) materialized, which entered service on October 28, 1962.

The following stations were listed for modernization. Loomis station ($33,000), which was already modernized with the implementation of a speed ramp from 1956 to 1964 Randolph/Wabash station ($40,000), which was already modernized in 1957 Wilson station ($1.80 million), which was being rebuilt from 1956 to 1960 to accommodate four tracks (the station previously had two through tracks, which bottlenecked train operations) Forest Park Terminal ($4.00 million) Logan Square Terminal ($75,000) Howard Street Terminal ($500,000) Kimball Terminal ($350,000)

Downtown subway plans (1960s–1970s) 1962 plan The CTA published a plan in 1962 proposing the following rapid transit lines: A subway loop below LaSalle Street, Randolph Street, Jackson Boulevard, and Grant Park; the loop was planned to replace its elevated counterpart. A rail line to McCormick Place