Proposed New York City Subway expansion (1929–1940)
Before unification in 1940, the City of New York made plans for expanding the Subway system. The first one, conceived in 1929, was to be part of the city-operated Independent Subway System (IND). By 1939, with unification planned, all three systems were included. Very few of these far-reaching lines were built, though provisions were made for future expansion on lines that intersect the proposals. The core Manhattan lines of the expansion were the Second Avenue Line (with an extension into the Bronx) and the Worth Street Line (connecting to the Rockaways). The Rockaways were eventually served by the subway via a city takeover of the Long Island Rail Road's Rockaway Beach Branch, which was also in the 1939 plans; the Second Avenue Subway is under construction as of 2007. It is of note that the majority of lines were designated to be built as elevated lines; this was likely a cost-cutting measure. The majority of the expansion was to occur in Queens, with the original proposal suggesting 52 miles of track be built in Queens alone.
The following provisions were made for connections and transfers to the new lines:
- At Second Avenue on the IND Sixth Avenue Line, a large open space was built above for the four-track IND Second Avenue Line. When the Second Avenue Line station is built, however, it won't use this space.
- At East Broadway on the IND Sixth Avenue Line (under Rutgers Street here), part of a two-track station was built for the IND Worth Street line line under East Broadway, above the existing line. This is now part of the mezzanine.
- At Broadway on the IND Crosstown Line, traces of stairways are visible going up to a six-track station on the line to Utica Avenue.
- At Utica Avenue on the IND Fulton Street Line, a four-track station above can be seen in the ceiling of the existing station. The existing mezzanine passes over the unused space.
- At Roosevelt Avenue on the IND Queens Boulevard Line, a two-track upper level was built for the Winfield Spur towards the line to the Rockaways. Unlike the other stations, this one was completed, except for track.
- A junction was built on the IND Queens Boulevard Line for the line under Van Wyck Boulevard. The junction was completed and has been connected to the IND Archer Avenue Line.
- The express tracks on the IND Sixth Avenue Line end at the curve into Essex Street; these were planned to continue towards the Rockaways.
- A line to the Rockaways would have split from the IND Eighth Avenue Line (under Church Street here), east under Worth Street. The junction was built and is used by the local tracks to World Trade Center.
- The tracks that the IND 63rd Street Line uses to split from the IND Sixth Avenue Line were built for a similar proposed line under 61st Street to the Second Avenue Subway.
- The completed IND 63rd Street Line, which the F train uses to cross the East River, was designed and built with bell mouths to allow for the construction of connections to the planned Second Avenue Subway for service to/from the north and south along Second Avenue. Those bellmouths will be used in later construction, unlike other Second System bellmouths.
- East of 63rd Drive – Rego Park on the IND Queens Boulevard Line, bellmouths were built for a proposed connection to the LIRR's Rockaway Beach Branch.
- The upper level relay tracks east of 179th Street on the IND Queens Boulevard Line were intended to continue towards Floral Park.
- East of 21st Street – Queensbridge, before the IND 63rd Street Line connects to the IND Queens Boulevard Line, the tracks veer left while the tunnel wall goes straight. The bellmouths were part of a proposed super-express bypass running under the LIRR mainline between Queens Boulevard and Forest Hills. This plan was not in the original Second System plan, but rather, in a 1950s plan that had the tracks from 21st Street – Queensbridge go straight to Forest Hills.
- The relay tracks east of Euclid Avenue on the IND Fulton Street Line were intended to continue towards Cambria Heights in Queens.
1929 plan details 
The first plan was made on September 15, 1929 (before the IND even opened), and is detailed in the table below. Cost is only for construction, and doesn't include land acquisition or other items.
|Line||Streets||From||To||Tracks||Route miles||Track miles||Cost||Notes|
|East Manhattan trunk line (Second Avenue Line)||Water Street - New Bowery - Chrystie Street||Pine Street||Houston Street||2 from Pine Street to Chambers Street
4 to Houston Street
|Second Avenue||Houston Street||Harlem River||4 to 61st Street
6 to 125th Street
4 to Harlem River
|Sixth Avenue - 61st Street||52nd Street||Second Avenue||2||1.1||2.2||$6,700,000||subway|
|(Rockaway Line)||Worth Street - East Broadway - Grand Street||Church Street||East River||2||1.95||3.9||$13,300,000||subway|
|(Utica Avenue Line)||Houston Street||Essex Street||East River||2||.93||1.86||$7,900,000||subway|
|Bronx trunk line||Alexander Avenue - Melrose Avenue - Boston Road||Harlem River||West Farms||4||3.97||15.88||$40,400,000||subway, with a portal between Vyse Avenue and 177th Street, then elevated into the existing IRT White Plains Road Line near 180th Street|
|Morris Park Avenue - Wilson Avenue||Garfield Street||Boston Road||2||3.5||7.9||$13,700,000||branching off the existing elevated IRT White Plains Road Line, and then going into subway|
|IRT Lafayette Avenue Line||163rd Street - Hunts Point - Lafayette Avenue - 177th Street||Washington Avenue at Brook Avenue||East Tremont Avenue||2||5.02||10.04||$12,900,000||subway to near Edgewater Road and Seneca Avenue, then elevated|
|Concourse Line Extension||Burke Avenue - Boston Road||Webster Avenue||Baychester Avenue||2||2.15||4.3||$8,900,000||extension of the Concourse Line|
|White Plains Road Line||180th Street||241st Street||4.40||13.2||$2,100,000||owned by IRT, to be taken over ("recaptured") by IND|
|Broadway Branch Line (Rockaway Line)||Broadway||East River||Havemeyer Street at South Fourth Street||2||3.16||13.5||$34,800,000||subway|
|Utica Avenue Line (and Rockaway Line from Havemeyer Street to Stuyvesant Avenue)||Grand Street - South Fourth Street - Beaver Street||East River||Stuyvesant Avenue||2 to Driggs Avenue
4 to Union Avenue
8 to Bushwick Avenue
4 to Stuyvesant Avenue
|Stuyvesant Avenue - Utica Avenue||Broadway||Flatbush Avenue||4||5.85||23.4||$39,300,000||subway to Avenue J, then elevated|
|Avenue S||Utica Avenue||Nostrand Avenue||2||1.1||2.2||$2,000,000||elevated|
|Nostrand Avenue||Avenue S||Voorhies Avenue||4||1.3||5.2||$3,200,000||elevated|
|Rockaway Line||Myrtle Avenue||Bushwick Avenue||Palmetto Avenue||4||1.34||5.36||$14,300,000||subway|
|Liberty Avenue||Fulton Street and Eastern Parkway||Grant Avenue||4||1.84||7.36||$13,500,000||subway extending the Fulton Street Line to a portal at Liberty Avenue and Crescent Street, then elevated to connect to the BMT Liberty Avenue Line (now part of the Fulton Street Line) at Grant Avenue|
|Nostrand Avenue Extension||Flatbush Avenue||Avenue S||2||2.25||4.5||$7,400,000||Extension of Nostrand Avenue Line as subway to Kings Highway, then elevated|
|Rockaway Line||Myrtle Avenue - Central Avenue||Palmetto Avenue||78th Street||4||2.1||8.4||$17,300,000||subway to Central Avenue near 73rd Place, then along the surface or elevated|
|98th Street - 99th Street - Hawtree Street||78th Street||Hammels Station||4 to Howard Beach
2 to Hammels
|9.2||26.2||$20,200,000||along the surface or elevated|
|Rockaway Beach Boulevard||Beach 116th Street||Mott Avenue||2||5.0||10.0||$7,400,000||along the surface or elevated|
|Newport Avenue||Beach 116th Street||Beach 149th Street||2||1.6||3.2||$2,400,000||along the surface or elevated|
|Winfield Spur||Garfield Avenue - 65th Place - Fresh Pond Road||Broadway and 78th Street||Central Avenue||2||3.34||6.68||$10,100,000||subway to 45th Avenue, then elevated to Fresh Pond Road, then subway|
|Liberty Avenue - 105th Avenue - Brinckerhoff Avenue - Hollis Avenue||Lefferts Boulevard||Springfield Boulevard||2||6.2||13.3||$10,700,000||elevated extension of the BMT Liberty Avenue Line (now part of the Fulton Street Line)
includes branch connection to BMT Jamaica Line (BMT) at 168th Street, via 180th Street and Jamaica Avenue
|Van Wyck Boulevard Line||137th Street - Van Wyck Boulevard||87th Avenue||Rockaway Boulevard||2||2.3||4.6||$6,600,000||subway to about 116th Avenue, then elevated|
|120th Avenue Line||120th Avenue - Springfield Boulevard||Hawtree Street near North Conduit Boulevard||Foch Boulevard||4 to Van Wyck Boulevard
2 to Foch Boulevard
|Bayside Line||Roosevelt Avenue - First Street - Station Road - 38th Avenue||Main Street||221st Street||3 to 147th Street
2 to 221st Street
|3.6||7.78||$9,600,000||extends the BMT/IRT Flushing Line as a subway to 155th Street, then elevated|
|College Point and Whitestone Line||149th Street - 11th Avenue||Roosevelt Avenue and 147th Street||11th Avenue and 122nd Street||2||3.4||6.8||$6,000,000||subway to 35th Avenue, then elevated|
|Long Island City-Horace Harding Boulevard Line||Ditmars Avenue - Astoria Boulevard - 112th Street - Nassau Boulevard (Long Island Expressway)||Second Avenue||Cross Island Boulevard||2 to Astoria Boulevard
4 to Parsons Boulevard
2 to Cross Island Boulevard
|8.1||26.71||$17,700,000||extends the BMT/IRT Astoria Line as an elevated, except that part of it may be depressed near Nassau Boulevard (Long Island Expressway)|
|Liberty Avenue Line||Grant Avenue||Lefferts Boulevard||3||2.3||6.9||$1,600,000||owned by BMT, to be taken over ("recaptured") by IND
now part of the Fulton Street Line
Later plans 
Later plans included the following:
- (1931 plan) A line splitting from the Second Avenue Line north of Houston Street, running southeast, merging with the Houston Street line, and crossing the East River from Stanton Street towards the huge line under South Fourth Street.
- (1931 plan) A line splitting from the Crosstown Line where it turns from Lafayette Avenue to Marcy Avenue, continuing under Lafayette Avenue and Stanhope Street to a junction with the line under Myrtle Avenue.
- (1939 plan) A line splitting from the South Brooklyn (Culver) Line at Fort Hamilton Parkway, and running under Fort Hamilton Parkway to end at 86th Street. A branch would split to run under Ovington Avenue and Senator Street, with a tunnel under the Narrows to Staten Island at the St. George Terminal. The line would split, with the north branch ending at Westervelt Avenue around Hamilton Avenue, and the south branch ending at Grant Street around St. Pauls Street. It was presumably designed this way to provide future service to both the Main Line and North Shore Staten Island Railway lines. The Staten Island Tunnel commenced construction in the 1920s, but was not completed.
- (unknown date) A third 2-track tunnel under the East River, from the north side of the South Fourth Street/Union Avenue station (as built for six tracks) west to Delancey Street.
- (unknown date) A line splitting from the Stuyvesant Avenue line, going southeast under Broadway.
- (unknown date) A line under Flushing Avenue from the huge line under Beaver Street to Horace Harding Boulevard (Long Island Expressway).
1968 plans 
- The IND Second Avenue Line with connections to IRT Dyre Avenue Line and IRT Pelham Line
- A crosstown line under 34th Street
- IND 63rd Street Line
- A new line running along Park Avenue in the Bronx
- Super Express bypass of IND Queens Boulevard Line with an extension along Interstate 495
- Archer Avenue Line to Springfield Boulevard
- IRT Nostrand Avenue Line extension to Avenue W in Sheepshead Bay
- A new line running under Utica Avenue to Avenue U
- Expansion of the BMT Canarsie Line under Flatlands Avenue
IND Second System planned services 
- A - 207th Street - Eighth Avenue - Fulton - Lefferts Boulevard
- AA - 168th Street - Eighth Avenue - Worth Street - South Fourth Street - Myrtle Avenue - Far Rockaway (non-rush)
- BB - 168th Street - Sixth Avenue - Worth Street - South Fourth Street - Myrtle Avenue - Far Rockaway (rush hours)
- CC - Concourse - Eighth Avenue - Houston Street - South Fourth Street - Utica Avenue
- D - Concourse - Sixth Avenue - Houston Street - South Fourth Street - Utica Avenue
- E - Archer - Queens Boulevard - Eighth Avenue - Fulton - Rockaway Park
- EE - Long Island Expressway - Queens Boulevard - 60th Street - BMT Broadway Line (Long Island Expressway added from ERA)
- F - Queens Boulevard - Sixth Avenue - Houston Street - Culver
- GG - Forest Hills - Crosstown - Church Avenue
- HH - Euclid Avenue - Rockaway Park - Far Rockaway (nights)
- HH - Cross Bay Boulevard - Far Rockaway (days)
- J - Crosstown - Myrtle Avenue - Roosevelt
- K - Far Rockaway - Roosevelt
- Q - Dyre Avenue - Second Avenue - Manhattan Bridge - BMT Southern Division
- R - 110th Street - Second Avenue - BMT Broadway Line
- T - Queens Boulevard Line - 63rd Street - Second Avenue - South Fourth - Utica Avenue
- V - Archer - Queens Boulevard - Sixth Avenue - Houston - Culver
- W - Pelham - Second Avenue - Court Street - Fulton - 105th Street (Long Island Expressway added from ERA)
Further reading 
- 100 Miles of Subway in New City Project; 52 of them in Queens, New York Times September 16, 1929 page 1
- NYCsubway.org - IND Second System
- NYCsubway.org - Roosevelt Avenue Terminal Station
- Abandoned Stations - IND Second System unfinished stations
- Abandoned Stations - Roosevelt Ave upper level
- Broadway-South 4 Street Station (junction with the Crosstown Line) photos
- Roosevelt Avenue-Winfield Spur Station (split from the Queens Boulevard Line) photos
- JoeKorNer - IND Second System (including a plan for a line to Staten Island)
- JoeKorNer - Roosevelt Rockaway Line (photos of the unused station)