Independent Subway System
|Independent Subway System|
|Owner||City of New York|
|Operator(s)||New York City Transit Authority|
|Depot(s)||Concourse Yard, Jamaica Yard, Pitkin Yard, 207th Street Yard|
|Rolling stock||R32, R42, R46, R68, R68A, R160|
|Track gauge||4 ft 8 1⁄2 in (1,435 mm)|
The Independent Subway System (IND or ISS), formerly known as the Independent City-Owned Subway System (ICOS) or the Independent City-Owned Rapid Transit Railroad, was a rapid transit rail system in New York City that is now part of the New York City Subway. It was first constructed as the "Eighth Avenue Line" in Manhattan in 1932.
One of three rail networks that became part of the modern New York City subway, the IND was intended to be fully owned and operated by the municipal government, in contrast to the privately operated or jointly-funded Interborough Rapid Transit Company (IRT) and Brooklyn–Manhattan Transit Corporation (BMT) companies. It was merged with these two networks in 1940.
The original IND service lines are the modern subway's A, B, C, D, E, F and G services. In addition, the BMT's M and R now run partly on IND trackage. The Rockaway Park Shuttle supplements the A service. For operational purposes, the IND and BMT lines and services are referred to jointly as the B Division.
- 1 Nomenclature
- 2 History
- 3 Timeline
- 4 As built
- 5 Line planning
- 6 Service letters
- 7 Platform lengths
- 8 References
- 9 Sources
- 10 External links
Until 1940, it was known as the Independent City-Owned Subway System (ICOS), Independent Subway System (ISS), or Independent City-Owned Rapid Transit Railroad. It became known as the IND after unification of the subway lines in 1940; the name IND was assigned to match the three-letter acronyms that the IRT and BMT used.
The first IND line was the Eighth Avenue Line in Manhattan, opened on September 10, 1932; for a while the whole system was colloquially known as the Eighth Avenue Subway. The original IND system was entirely underground in the four boroughs that it served, with the exception of a short section of the IND Culver Line containing two stations spanning the Gowanus Canal in the Gowanus section of Brooklyn.
In the early 1920s, Mayor John Hylan proposed a complex series of city-owned and operated rapid transit lines to compete with the BMT and IRT, especially their elevated lines. The New York City Transit Commission was formed in 1921 to develop a plan to reduce overcrowding on the subways. The original plans included:
- Two major trunk lines in midtown Manhattan, with one running under Eighth Avenue and one under Sixth Avenue, which already had an elevated line
- A crosstown subway under 53rd Street (connecting with the Eighth and Sixth Avenue subways) running under the East River to Queens Plaza (Long Island City), meeting with a Brooklyn–Queens crosstown line, and continuing under Queens Boulevard and Hillside Avenue to 179th Street, where bus service would converge
- A subway under the Grand Concourse in the Bronx, diverging from the Eighth Avenue Line in Manhattan at 145th Street and Saint Nicholas Avenue
Opening and progress through 1933
First Manhattan trunk line, 1932
On September 10, 1932, the Eighth Avenue Line opened from 207th Street to Chambers Street, inaugurating the IND. In February 1933 the Cranberry Street Tunnel opened, along with the Eighth Avenue Line from Chambers Street to Jay Street – Borough Hall. On the northern end of the construction, in the Bronx, the connecting Concourse Line opened on July 1, 1933 from 205th Street to 145th Street. On the IND's opening day, it had a relatively small subway car fleet of 300 cars, while the IRT had 2,281 subway and 1,694 elevated cars, and the BMT had 2,472 cars.
The new IND Eighth Avenue Line was built using 1,000,000 cubic yards (27,000,000 cu ft) of concrete and 150,000 short tons (140,000,000 kg) of steel. The roadbed of the new subway was expected to last 30 years. At the time of the line's opening, other portions of the Independent Subway System were under construction, including five underwater tunnels:
- Cranberry Street Tunnel, 8,487 feet (2,587 m) long
- Rutgers Street Tunnel, 5,479 feet (1,670 m) long
- 53rd Street Tunnel, 5,589 feet (1,704 m) long
- Concourse Tunnel, 5,397 feet (1,645 m) long
- Greenpoint Tube, 4,790 feet (1,460 m) long
There was some vandalism on the IND Eighth Avenue Line's opening day, as some of the uptown stations were broken into by people who clogged turnstile slots with gum and other objects. Two months after the IND opened for business, three exits from the 96th Street and 103rd Street stations – at 95th and 97th Streets and at 105th Street, respectively – were closed due to theft.
First branch lines
In October 1932, the Queens Boulevard Line opened from Jackson Heights – Roosevelt Avenue to the lower level of 50th Street on the Eighth Avenue Line, connecting the Queens and Manhattan lines. In Queens, the Crosstown Line opened from Queens Plaza to Nassau Avenue.
Second Manhattan trunk line, 1936–1937
On January 1, 1936, the Sixth Avenue Line opened from West Fourth Street (where it splits from the Eighth Avenue Line) to East Broadway. During construction, streetcar service along Sixth Avenue was terminated. The city could either restore it upon the completion of construction or abandon it immediately; as the city wanted to tear down the IRT Sixth Avenue Line right away and save on the costs of shoring it up while construction proceeded underneath it, the IRT Sixth Avenue Line was purchased for $12.5 million and terminated by the city on December 5, 1938., with the steel from the el sold to Japan. Two years later, on December 15, 1940, local service was begun; express service wasn't begun until 1968, after the Chrystie Street Connection opened.
More branch lines open
On April 9, 1936 the Fulton Street Line opened from Court Street to Rockaway Avenue, along with connecting tracks from Jay Street. The Sixth Avenue Line and Rutgers Street Tunnel opened from East Broadway to Jay Street. 
Mayor John Hylan proposed some never-built lines in 1922 even before the first leg of the IND was completed. These lines included:
- A West Side trunk line in Manhattan between 14th Street and the city limits at Yonkers. The line would be 4 tracks between 14th St. and 162nd Street, 3 tracks to Dyckman Street, and 2 tracks to the terminal. There would be a two-track spur from 162nd St. to 190th St. via Amsterdam Avenue. From 14th Street, the line would split; two tracks would connect to the BMT Canarsie Line and two tracks would continue south to a loop at Battery Park and an East River tunnel to Atlantic Avenue and Hicks Street, Brooklyn. Supposedly, there was also a plan of a line to Red Hook.
- A trunk line, 4 tracks, on First Avenue from the Harlem River to 10th Street. From 10th Street, the line would split. Two tracks would run via Third Avenue and the Bowery to a new Lafayette Avenue subway in Brooklyn. The other two would run to a loop near City Hall. From the Harlem River, the line would run to 161st Street, and split into two 3-track routes: one to Fordham Road & Southern Blvd and the other to Webster Ave. & Fordham Road, where it would join the current IRT White Plains Road line and continue to 241st Street. Since this portion of the IRT El was already built to BMT clearances, and Hylan's system would consider using BMT clearances as well, all that would have to be done along this section is shave back the platforms.
- A line from 125th Street (near today's Henry Hudson Parkway) crosstown, to and across the East River, to Astoria, Queens, likely connecting to the BMT Astoria Line.
- A new subway line, with between two and four tracks at various areas, from approximately the Hunters Point Avenue station on today's IRT Flushing Line in Queens, heading in a southeasterly direction to Lafayette Avenue, Brooklyn. At Lafayette Avenue, the line would split. Two tracks would turn into a four-track line along Lafayette Avenue. The other two tracks would run to Flatbush and Franklin Avenues.
- A 4-track subway line from Brooklyn's Borough Hall via the Lafayette Avenue subway to Bedford Avenue. From there it was three tracks to Broadway to Cypress Hills, Brooklyn where the line would continue on the present-day BMT Jamaica Line. (The line would have ended at 168th Street, where the BMT Jamaica Line once ended.) The subway would have run directly under the line along Broadway giving it direct competition for passengers, and (in Hylan's opinion) draining revenues from the BMT. Two tracks of the Lafayette Avenue subway would connect with the proposed First Avenue line.
- A new branch off the IRT Eastern Parkway Line in Brooklyn onto Utica Avenue, running under Utica to Flatlands Avenue.
- A 4-track subway under Flatbush Avenue in Brooklyn to Nostrand Avenue, to Emmons Avenue in Sheepshead Bay, turning west onto Emmons Avenue to Surf Avenue in Coney Island. A branch of this line would head out to Floyd Bennett Field under Flatbush Avenue.
- Extension of the BMT Canarsie Line to the BMT Jamaica Line somewhere beyond 121st Street in Queens.
- A new line running from Prospect Avenue via Fort Hamilton Parkway, to 10th Avenue, terminating at 90th Street. BMT Culver Line trains would use this line.
- Extension of the BMT Fourth Avenue Line in Brooklyn, south to Bay Ridge – 95th Street. (This was the only other line that was complete.)
- Extension of the BMT Fourth Avenue Line east to the Fort Hamilton Parkway Line and the BMT West End Line.
- A two-track line from the BMT Fourth Avenue Line at 67th Street to Staten Island via the Staten Island Tunnel.
- Extension of the IRT New Lots Line from New Lots Avenue to Lefferts Boulevard.
- Extension of the IRT Flushing Line to Bell Boulevard in Bayside via Main Street, Kissena Boulevard, and Northern Boulevard.
- A branch off the IRT Flushing Line to Jamaica from Roosevelt Avenue.
A major expansion of the IND was first planned in 1929. It would have added over 100 miles of new routes in Manhattan, Brooklyn, Queens, and the Bronx, merging with, intersecting or extending the existing IND rights-of way. It was claimed that this expansion, combined with the operating IRT, BMT, and IND lines, would provide subway service within a half mile of anyone's doorstep within these four boroughs. Pricing—excluding acquisition and equipment costs—was estimated at US$438 million; the entire first phase had only cost US$338 million (including acquisition and equipment costs). Not long after these plans were unveiled, the Wall Street Crash of 1929 occurred and the Great Depression was ushered in, and the plans essentially became history overnight. Various forms of the expansion resurfaced in 1939, 1940, 1951, 1968, and 1998 but were never realized. This was the time when the IND had planned widespread elevated construction.
- March 14, 1925: Groundbreaking of 8th Avenue subway takes place at 123rd Street and St. Nicholas Avenue.
- July 8, 1931: First train of R1s leaves Coney Island at 11:35am and runs via the BMT Sea Beach Line to Times Square. The trip took 42 minutes.
- September 10, 1932: IND Eighth Avenue Line opens.
- February 1, 1933: IND expands to Jay Street, Brooklyn. Until June 24, 1933, High Street is skipped.
- March 20, 1933: Extended to Bergen Street.
- July 1, 1933: IND service extended to Norwood – 205th Street in the Bronx.
- August 19, 1933: IND service extended to Roosevelt Avenue in, Queens.
- October 7, 1933: Brooklyn service extended to Church Avenue.
- January 1, 1936: The IND Sixth Avenue Line between West Fourth Street and East Broadway opens.
- April 9, 1936: Service extended from East Broadway to Jay Street. Additionally, the IND Fulton Street Line is extended from Jay Street to Rockaway Avenue. Court Street shuttle in service.
- December 30, 1936: Queens service extended to Union Turnpike.
- April 24, 1937: Queens service extended to 169th Street.
- July 1, 1937: IND Crosstown Line between Nassau Avenue and Hoyt–Schermerhorn Streets opens for service.
- April 30, 1939: The IND World's Fair Line opens.
- October 28, 1940: Last train runs on the IND World's Fair Line.
- December 15, 1940: The local tracks of the Sixth Avenue Line opened from its connection to the Eighth Avenue Line at 59th Street – Columbus Circle to West Fourth Street – Washington Square, along with the express tracks north of 34th Street – Herald Square.
- December 30, 1946: The Fulton Street Line opens from Rockaway Avenue to Broadway – East New York (now Broadway Junction).
- June 1, 1946: The Fulton Street Line local spur from Court Street (IND Fulton Street Line) closes. (This spur would have been extended into lower Manhattan to connect with the Second Avenue Subway under 1939 plans.)
- November 28, 1948: The Fulton Street Line opens from Broadway – East New York to Euclid Avenue.
- December 11, 1950: The Queens Boulevard Line is extended from 169th Street to its current terminus at 179th Street.
- 1950s: The IND was extended over two pieces of elevated line that were disconnected from the original BMT system: the BMT Culver Line in 1954, and the Liberty Avenue extension of the BMT Fulton Street Line in 1956.
- October 30, 1954: The Culver Ramp opens, connecting the IND Culver Line to the BMT Culver Line at Ditmas Avenue. IND trains begin operating over the BMT Culver Line to Coney Island – Stillwell Avenue.
- April 29, 1956: The Liberty Avenue Elevated, the easternmost section of the former BMT Fulton Street Line, is connected to the IND Fulton Street Line. IND service is extended from Euclid Avenue out to Lefferts Boulevard via a new station at Grant Avenue.
- June 28, 1956: The Rockaway Line opens to Beach 25th Street after conversion from the Long Island Rail Road's Rockaway Beach Branch. It is extended to its current terminal, Far Rockaway – Mott Avenue on January 16, 1958.
- November 26, 1967: The Chrystie Street Connection opens, connecting the Sixth Avenue Line to the Manhattan Bridge and the south Brooklyn BMT lines.
- November 27, 1967: The Sixth Avenue Line express tracks open from 34th Street – Herald Square to West Fourth Street – Washington Square.
- July 1, 1968: The Sixth Avenue Line is extended from 47th–50th Streets – Rockefeller Center to 57th Street; the remaining portion of the Chrystie Street Connection opens, connecting the Sixth Avenue Line to the Williamsburg Bridge.
- December 11, 1988: The IND Archer Avenue Line opens from Jamaica Center – Parsons/Archer to Jamaica – Van Wyck.
- October 29, 1989: The IND 63rd Street Line—including the 63rd Street Tunnel—opens from 57th Street to 21st Street – Queensbridge.
- December 16, 2001: The 63rd Street Line is extended from 21st Street – Queensbridge to merge with the Queens Boulevard Line.
The Bronx and Manhattan
- Concourse Line (B D trains): under the Grand Concourse from 205th Street south to 161st Street, then west under the Harlem River into Manhattan and south to the Eighth Avenue Line (parallel to the IRT Jerome Avenue Line)
- Eighth Avenue Line (A C E trains): from 207th Street, south roughly under Broadway; under Saint Nicholas Avenue, Eighth Avenue, Greenwich Avenue, Sixth Avenue (with a junction with the Sixth Avenue Line/Houston Street Line), Church Street, and Fulton Street; under the East River via the Cranberry Street Tunnel into Brooklyn, to the Fulton Street Line (parallel to the IRT Ninth Avenue Line)
- Sixth Avenue Line (B D F M trains): from a split from the Eighth Avenue Line at 53rd Street, two blocks east to Sixth Avenue, then south under Sixth Avenue to a junction with the Eighth Avenue Line north of Houston Street, then east under Houston Street and south under Essex Street and Rutgers Street to the Rutgers Street Tunnel to Brooklyn – parallel to the IRT Sixth Avenue Elevated
- Queens Boulevard Line (E M trains): from the 53rd Street Tunnel from Queens, west under 53rd Street past a junction with the Sixth Avenue Line to merge with the Eighth Avenue Line – partly parallel to the IRT Sixth Avenue Elevated connection to the IRT Ninth Avenue Elevated along 53rd Street
East River Crossings
- 53rd Street Tunnel (E M trains) – along the Queens Boulevard Line
- Rutgers Street Tunnel (F train) – connecting the Sixth Avenue Line to the Culver Line
- Cranberry Street Tunnel (A C trains) – connecting the Eighth Avenue Line to the Fulton Street Line
Brooklyn and Queens
- Queens Boulevard Line (E F M R trains): from 179th Street, west under Hillside Avenue, Queens Boulevard, Broadway, Northern Boulevard and 44th Drive to the 53rd Street Tunnel to Manhattan
- Crosstown Line (G train): from the Queens Boulevard Line at Queens Plaza, south under Jackson Avenue, Manhattan Avenue, Union Avenue, Marcy Avenue and Lafayette Avenue, coming into the middle of the Fulton Street Line and connecting south into the Culver Line
- Culver Line (originally the Smith Street Line) (F G trains): from the Rutgers Street Tunnel, south under Jay Street and Smith Street, coming to the surface and turning east over the Gowanus Canal at Ninth Street, then back underground, under Ninth Street, Prospect Park West, Prospect Avenue, Fort Hamilton Parkway and Mcdonald Avenue, ending at Church Street (later extended south along the BMT Culver Line)
- Fulton Street Line (A C trains): from Court Street (now the New York Transit Museum) and the Cranberry Street Tunnel east under Fulton Street to Rockaway Avenue (later extended east along the BMT Liberty Avenue Elevated) – parallel to the BMT Fulton Street Elevated
Extensions after 1940
The following extra extensions and connections were built after unification in 1940:
- 60th Street Tunnel Connection (R train): connecting the BMT's 60th Street Tunnel to the Queens Boulevard Line
- 63rd Street Line (F train): connecting the Sixth Avenue Line and the Queens Boulevard Line through the 63rd Street Tunnel, and connecting to the BMT 63rd Street Line
- Archer Avenue Line (E train): from the Queens Boulevard Line at Van Wyck Boulevard south and east to Jamaica Center
- Chrystie Street Connection, connecting the Houston Street Line (Sixth Avenue Line) to the BMT lines over the Williamsburg Bridge (M train) and Manhattan Bridge (B D trains)
- Culver Line (F train): extended south along the ex-BMT Culver Line
- Fulton Street Line (A train): extended east to and over the BMT Liberty Avenue Elevated
- Queens Boulevard Line (E F trains): extended east to 179th Street
- Rockaway Line (A train): connecting to the Fulton Street Line east of Rockaway Boulevard
The following extension is under construction:
Many IND lines were designed to be parallel to existing IRT and BMT subway lines.
- The IND Concourse Line is within one block of the IRT Jerome Avenue Line for most of its length. It was also planned to replace the then-NYW&B-owned line as well as the IRT White Plains Road Line.
- The IND Eighth Avenue Line is within 0.25 miles (0.40 km) of the IRT Broadway – Seventh Avenue Line and the IRT Lenox Avenue Line for most of its length. It was designed to replace the IRT Ninth Avenue Line.
- The IND Sixth Avenue Line was designed to replace the IRT Sixth Avenue Line.
- The IND Fulton Street Line is within 0.5 miles (0.80 km) of the IRT Eastern Parkway Line and the IRT New Lots Line for most of its length in Brooklyn. It was designed to replace the BMT Fulton Street Line.
- The IND Crosstown Line was designed to replace BMT streetcars.
Additionally, some never-built lines were also to serve this purpose.
- The IND Second Avenue Line was designed to be within 0.25 miles (0.40 km) of the IRT Lexington Avenue Line and replace the IRT Second Avenue Line and the IRT Third Avenue Line.
- The IRT Dyre Avenue Line and IRT Pelham Line were to be recaptured by the IND Second Avenue Line.
- The IND Utica Avenue Line and the IND Archer Avenue Line were both designed to replace parts of the BMT Jamaica Line. The latter would also be planned to replace the LIRR Atlantic Branch.
As originally designed, the IND train identification scheme was based on three things: the Manhattan trunk line served (8th Avenue or 6th Avenue), the northern branch line served (Washington Heights, Grand Concourse/Bronx, or Queens Boulevard), and the service level (Express or Local). The 8th Avenue routes were A, C, and E, while the 6th Avenue routes were B, D, and F. A and B served Washington Heights, C and D served the Grand Concourse, and E and F served Queens Boulevard (via the 53rd Street Tunnel). A single letter indicated express service, and a double letter indicated local service. In addition, G was used for Brooklyn-Queens "Crosstown" service, and H was used for any service on the extended Fulton Street (Brooklyn) line that did not originate in Manhattan.
The first designations were as follows:
|A||AA||Eighth Avenue – Washington Heights|
|BB||Sixth Avenue – Washington Heights|
|C||CC||Eighth Avenue – Concourse|
|D||Sixth Avenue – Concourse|
|E||Eighth Avenue – Queens Boulevard|
|F||Sixth Avenue – Queens Boulevard|
Virtually all possibilities were used at one time or another, either in regular service or as brief special routes. The "G" single-letter service was used for G service to World's Fair Station in 1939.
|A||Washington Heights Express||207th Street – Lefferts Boulevard or Far Rockaway or Rockaway Park (via Eighth Avenue)||still in use|
|AA||Washington Heights Local||168th Street – Hudson Terminal (via Eighth Avenue)||became K (no longer operative)|
|BB||Washington Heights Local||168th Street – 34th Street (via Sixth Avenue)||became B (now goes from Bedford Park Boulevard to Brighton Beach)|
|C||Bronx Concourse Express||205th Street – Utica Avenue (via Eighth Avenue)||no longer operated; combined into A and D trains|
|CC||Bronx Concourse Local||Bedford Park Boulevard – Hudson Terminal (via Eighth Avenue)||became C (now goes from 168th Street to Euclid Avenue)|
|D||Bronx Concourse Express||205th Street – Coney Island (via Sixth Avenue) and Culver Line||still in use, though trains now use the West End Line|
|E||Queens–Manhattan Express||179th Street – Rockaway Park or Hudson Terminal (via Eighth Avenue and Houston Street)||still in use, though all trains go from Jamaica Center to Hudson Terminal (now called World Trade Center)|
|F||Queens–Manhattan Express||179th Street – Hudson Terminal or Coney Island (via Sixth Avenue)||still in use, though all trains go to Coney Island or Kings Highway|
|GG||Queens Brooklyn Local||Forest Hills – Church Avenue (via Crosstown Line)||became G, though all trains short turn at Court Square|
|HH||Court Street Shuttle||Court Street – Hoyt–Schermerhorn Streets||no longer operated, but the trackage is used for moving trains in and out of the New York Transit Museum, located in the Court Street station|
|HH||Rockaway Local||Euclid Avenue – Rockaway Park or Far Rockaway||became H, then S, though all trains only go to Rockaway Park|
After the Chrystie Street Connection opened, the original IND Service Letter scheme was gradually abandoned. All lines, whether local or express, now use a single letter, and only the 8th Avenue/6th Avenue distinction (A, C, E vs. B, D, F) has been maintained.
The IND was built with longer platforms than those of the IRT or BMT. Initial plans called for stations to be built with 660 feet (200 m) long platforms to accommodate trains of eleven 60 feet (18 m) cars. However, these lengths were shortened, as stations on the IND Eighth Avenue Line between 72nd Street and 163rd Street – Amsterdam Avenue have lengths of exactly 600 feet (180 m). There were two exceptions: 96th Street was 615 feet (187 m) on both levels, as that was the standard length of platforms built for the IND after the 1940s. The 81st Street – Museum of Natural History station had an uptown platform that was 630 feet (190 m) long, and a downtown platform that was 615 feet (187 m). Platforms of exactly 600 feet (180 m) length can also be found on the IND Queens Boulevard Line between Elmhurst Avenue and 67th Avenue.
Some of the IND Sixth Avenue Line stations, on the other hand, have much greater platform lengths. In 34th Street – Herald Square, the uptown platform was originally 745 feet (227 m) (long enough to hold a 12-car train of 60 feet (18 m) cars), and the downtown platform was originally 685 feet (209 m). Both platforms of the 23rd Street station are 670 feet (200 m), and 47th–50th Streets – Rockefeller Center has platforms that are 665 feet (203 m).
- nycsubway.org—History of the Independent Subway
- "About New York; Alphabet Soup: Telling an IRT From a BMT". The New York Times. 30 June 1990. Retrieved 14 March 2016.
- "Gay Midnight Crowd Rides First Trains in New Subway". New York Times. September 10, 1932. p. 1.
- "Two Subway Routes Adopted by City". New York Times. August 4, 1923. p. 9.
- "Plans Now Ready to Start Subways". New York Times. March 12, 1924. p. 1.
- "City Subway Adds a New Link Today". New York Times. March 20, 1933. p. 17.
- "Two Subway Links Start Wednesday". The New York Times. April 6, 1936. p. 23. Retrieved October 7, 2011.
- "New Subway Link Opened by Mayor". The New York Times. April 9, 1936. p. 23. Retrieved October 7, 2011.
- nycsubway.org—IND Queens Boulevard Line
- nycsubway.org—IND Second System
- Track diagram of planned underground Fulton Street Line extension in Queens
- "Board of Transportation – 1951". Thejoekorner.com. Retrieved 2014-03-25.
- "1968 NYCTA Expansion Plans (Picture)". Second Avenue Sagas. Retrieved December 2013. Check date values in:
- Program for Action maps from thejoekorner.com
- "Flashback To 1999 | www.qgazette.com | Queens Gazette". www.qgazette.com. 2007-06-27. Retrieved 2014-03-25.
- MTA releases Second Avenue subway images, says project on track NY Daily News, November 5, 2013
- nycsubway.org—Subway FAQ: Letter, Number, and Color Designation Systems
- Brian J. Cudahy, Under the Sidewalks of New York, Revised Edition (Lexington, Mass: The Stephen Greene Press, 1988)
- Joseph Cunningham and Leonard DeHart, A History of the New York City Subway System: The Independent System and City Ownership, 1977
- Gerhard M. Dahl, Transit Truths (Brooklyn-Manhattan Transit Corporation, Brooklyn, NY, 1924)
- Stan Fischler, The Subway: A Trip Through Time on New York's Rapid Transit (Flushing, NY: H & M Productions, Inc., 1997)
- Herbert George, Change at Ozone Park (RAE Publishing Inc., Flanders, NJ, 1993)
- Alan Paul Kahn and Jack May, The Tracks of New York, Number 3 (New York: Electric Railroaders' Association, Inc., 1977)
- Frederick A. Kramer, Building the Independent Subway (New York: Quadrant Press, Inc., 1990)
- Frederick A. Kramer, Subway to the World's Fair (Westfield, NJ: Bells and Whistles, 1991)
- Robert W. Snyder, Transit Talk (New York Transit Museum, Brooklyn, NY and Rutgers University Press, New Brunswick, NJ and London, 1997)
- Electric Railroaders' Association: Headlights Magazine: August 1956, February 1968, February 1973, August 1974, July/September 1977, May/June 1988
- The New York Times (before 1977), most notably: 1929: September 16, 22; 1932: September 4, 8, 9, 10; 1940: June 1, 2, 12, 13; 1967: November 22, 26, 28
- Unpublished document from New York City Transit Authority—precursor to "Facts and Figures", 1977