Proposed expansion of the New York City Subway

Since the opening of the original New York City Subway line in 1904, and throughout the subway's history, various official and planning agencies have proposed numerous extensions to the subway system. The first major expansion of the subway system was the Dual Contracts, a set of agreements between the City of New York and the IRT and the BRT. The system was expanded into the outer reaches of the Bronx, Brooklyn, and Queens, and it provided for the construction of important lines in Manhattan. This one expansion of the system provided for a majority of today's system.

Even with this expansion, there was a pressing need for growth. In 1922, Mayor John Hylan put out his plan for over 100 miles of new subway lines going to all five boroughs. His plan was intended to directly compete with the two private subway operators, the IRT and the BMT. This plan was never furthered. The next big plan, and arguably the most ambitious in the subway system's history, was the "Second System". The 1929 plan by the Independent Subway to construct new subway lines, the Second System would take over existing subway lines and railroad rights-of-way. This plan would have expanded service throughout the city with 100 miles of subway lines. A major component of the plan was the construction of the Second Avenue Subway. The Stock Market Crash of 1929 put a halt to the plan, however, and subway expansion was limited to lines already under construction by the IND.

During the 1930s and 1940s, the plans were revised, with new plans such as a line to Staten Island and a revised line to the Rockaways. In the late 1940s and 1950s, a Queens Bypass line via the Long Island Rail Road's Main Line was first proposed as a branch of the still-planned Second Avenue Subway. In addition, capacity on existing lines became improved through the construction of strategic connections such as the Culver Ramp, the 60th Street Tunnel Connection, and the Chrystie Street Connection, and through the rebuilding of DeKalb Avenue Junction. These improvements were the only things to come out of these plans. Eventually, these plans were modified to what became the Program for Action, which was put forth by the New York City Transit Authority in 1968. This was the last plan for a major expansion of the subway system. The plan included the construction of the Second Avenue Subway, a Queens Bypass line, a line replacing the Third Avenue El in the Bronx, and other extensions in the Bronx, Queens, and Brooklyn. While ambitious, very little of the plan was completed, mostly because of the financial crisis in the 1970s.

Until the 1990s, there was little focus on expansion of the system because the system was in a state of disrepair, and funds were allocated to maintaining the existing system. In the 1990s, however, with the system in better shape, the construction of the Second Avenue Subway was looked into again. Construction of the Second Avenue Subway started in 2007, and the first phase was completed in 2017. Since the 1990s, public officials and organizations such as the Regional Plan Association have pushed for the further expansion of the system. Projects such as the TriboroRx, a circumferential line connecting the outer boroughs, the reuse of the Rockaway Beach Branch, and the further expansion of the Second Avenue Subway have all been proposed, albeit mostly unfunded.

Triborough System

thumb|200px|A 1910 plan for an [[Interborough Rapid Transit Company|IRT expansion]]

The Triborough System was a proclamation for new subway lines to the Bronx and Brooklyn. The new lines include the IRT Lexington Avenue Line, IRT Pelham Line, and IRT Jerome Avenue Line. The Manhattan Bridge line described below later became the BMT West End Line, BMT Fourth Avenue Line, the BMT Sea Beach Line, and the Nassau Street loops.

<blockquote>The route of the new subway ... comprises a main trunk north and south through Manhattan Borough on Lexington Avenue and Irving Place from the Harlem River to Tenth St. and on Broadway, Vesey and Church Sts. from Tenth St. to the Battery; two branches in Bronx Borough, one northeast via 138th St. Southern Boulevard and Westchester Ave. to Pelham Bay Park. the other northerly via River Ave. and Jerome Ave. to Woodlawn Road, connecting with the Manhattan trunk by a tunnel under the Harlem River; a Manhattan-Brooklyn line extending from the North River via Canal Street across the East River on the Manhattan Bridge to connect with the Fourth Avenue subway in Brooklyn now being built, which thus becomes an integral part of the larger system; two branches southerly from the Fourth Ave. line extending south to Fort Hamilton and southeast to Coney Island; and a loop feeder line in Brooklyn through Lafayette Ave. and Broadway, connecting with the Fourth Ave. line at one end. and at the other crossing the Williamsburg Bridge and entering the Centre Street Loop subway in Manhattan which is thus also incorporated in the system.</blockquote>

In 1911, William Gibbs McAdoo, who operated a competing subway company called the Hudson & Manhattan Railroad, proposed building a line under Broadway between Hudson Terminal and Herald Square. He later proposed that the Broadway line be tied into the IRT's original subway line in Lower Manhattan. The Broadway line, going southbound, would merge with the local tracks of the IRT Lexington Avenue Line in the southbound direction at 10th Street. A spur off the Lexington Avenue Line in Lower Manhattan, in the back of Trinity Church, would split eastward under Wall Street, cross the East River to Brooklyn, then head down the Fourth Avenue Line in Brooklyn, with another spur underneath Lafayette Avenue.

The Triborough System later became part of the Dual Contracts, signed on March 19, 1913 and also known as the Dual Subway System. These were contracts for the construction and/or rehabilitation and operation of rapid transit lines in New York City. The contracts were "dual", in that they were signed between the City and the IRT and Municipal Railway Company, a subsidiary of the BRT (later BMT).

Some lines proposed under the Contracts were not built, most notably an IRT line to Marine Park, Brooklyn (at what is now Kings Plaza) under either Utica Avenue, using a brand-new line, or Nostrand Avenue and Flatbush Avenue, using the then-new IRT Nostrand Avenue Line. There were also alternate plans for the Nostrand Avenue Line to continue down Nostrand Avenue to Sheepshead Bay.

Mayor Hylan's plan

thumb|200px|A 1920 plan for expansion

On August 28, 1922, Mayor John Francis Hylan unveiled his own plans for the subway system, which was relatively small at the time. His plan included building over of new lines and taking over nearly of existing lines. By the end of 1925, all of these routes were to have been completed. The lines were designed to compete with the IRT and BMT.

Hylan's plan contained the following lines:

A line running along Manhattan's West Side, stretching from the edge of the city at Yonkers to 14th Street. It would be a two-track line south to Dyckman Street, a three-track line to 162nd Street, and then-on it would be a four-track line. The line would have two southern branches that would diverge at 14th Street. A connection to the BMT Canarsie Line would use a pair of the tracks, while the other pair would go to Atlantic Avenue and Hicks Street in Brooklyn through an East River tunnel. Then it would turn down to Red Hook. There would also be a loop at Battery Park. Another branch would be built; it would consist of two tracks, and would go between 162nd Street and 190th Street via Amsterdam Avenue.
A First Avenue line, consisting of four tracks, would stretch from the Harlem River to City Hall. At 10th Street, the line would cease to be a four-track line, with the line splitting into two branches. One branch would run to a loop near City Hall, while the other would go to a new Lafayette Avenue line in Brooklyn, running via Third Avenue and the Bowery. On the northern end, at 161st Street, the line would split into two 3-track lines. One of the lines would go to Southern Boulevard and Fordham Road; the other would continue to 241st Street after merging with the existing IRT White Plains Road Line at Fordham Road and Webster Avenue.
A line from Astoria, Queens, likely connecting to the BMT Astoria Line, across the East River and via 125th Street (near today's Henry Hudson Parkway).
A line running from Hunters Point in Queens heading southeast to Lafayette Avenue in Brooklyn. The line would consist of between two and four tracks, and at Lafayette Avenue, the line would split. Two of them would continue as a Lafayette Avenue, but would then become four tracks. The remaining two tracks would run to Franklin and Flatbush Avenues.
A new 4-track trunk line along Lafayette Avenue in Brooklyn from Borough Hall to Bedford Avenue. The line would narrow to three tracks to Broadway. Then the line would have continued underneath the BMT Jamaica Line to 168th Street. By running underneath the Jamaica Line, the line would directly compete with the BMT. A two-track connection would also be provided to a First Avenue line.
A new line running under Utica Avenue to Flatlands Avenue. The line would be a branch of the IRT Eastern Parkway Line.
A four-track Flatbush Avenue line to Emmons Avenue in Sheepshead Bay, before turning west to Surf Avenue in Coney Island via Emmons Avenue. Service to Floyd Bennett Field would be provided with a branch via Flatbush Avenue.
The BMT Canarsie Line would be extended past 121st Street in Queens to the BMT Jamaica Line.
A new line, which would run from 90th Street to Prospect Avenue, that would go via Fort Hamilton Parkway and 10th Avenue would be used by BMT Culver Line trains.
Extension of the BMT Fourth Avenue Line in Brooklyn, south to Bay Ridge–95th Street.
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.

An extension of the Fourth Avenue Line to 95th Street.
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.

Major Phillip Mathews disagreed with the Board of Transportation's plan, and in response, he published a report, on December 24, 1926, titled "Proposed Subway Plan for Subway Relief and Expansion". He said that that congestion would not be addressed for Brooklyn and the Bronx; only the planned Grand Concourse line would alleviate congestion, in this case congestion on the IRT Jerome Avenue Line. There would be little relief on the two lines jointly-operated between the IRT and the BMT. He came up with his own plan. He proposed that the Eighth Avenue Line, through a connection from Fulton or Wall Streets to Chambers Street, be connected to the BMT's lines to Coney Island, with a possible connection at the Manhattan Bridge's south side.

<blockquote>Principal features of a comprehensive plan for passenger transportation between communities in the nine northern counties of New Jersey and the city of New York are outlined in a report submitted on Jan. 15 to the Legislature of the state by the North Jersey Transit Commission. A preliminary report presented about a year ago was abstracted in Electric Railway Journal for Feb. 7, 1925... The ultimate object of the program recommended is the creation of a new electric railway system comprising of route, and the electrification of of railroad now operated by steam. As the first step it is proposed to construct an interstate loop line in length connecting with all of the north Jersey commuters' railroads and passing under the Hudson River into New York City by two tunnels, one uptown and one downtown. A new low-level subway through Manhattan would complete the loop. Construction costs of this preliminary project are estimated at $154,000,000, with $40,000,000 additional for equipment. The cost of power facilities is not included in this estimate.

In 1963, three major commuter groups in New Jersey made expansion proposals. One of them would have involved an extension of the IRT Flushing Line under the Hudson River with a three-track tunnel and then connect with the New York, Susquehanna and Western Railroad.

In 1986, the Regional Plan Association suggested extending the IRT Flushing Line to New Jersey's Meadowlands Sports Complex.

In April 2012, citing budget considerations, the director of the MTA, Joe Lhota, said that it was doubtful the extension would be built in the foreseeable future, suggesting that the Gateway Project was a much more likely solution to congestion at Hudson River crossings. A feasibility study commissioned by the city and released in April 2013 revived hope for the project, however, with Mayor Bloomberg saying "Extending the 7 train to Secaucus is a promising potential solution ... and is deserving of serious consideration."

In 2017, a further extension of the 7 train to New Jersey was suggested once again, this time as an alternative to constructing a replacement for the Port Authority Bus Terminal. An alternative would include a new terminal at Secaucus Junction in conjunction with the 7 extension. In February 2018, it was revealed that the Port Authority of New York and New Jersey had advertised for consultants to write a feasibility study for such an extension, and that it had received bids from several companies. This extension was being planned along with the Gateway Project and, if built, would be able to accommodate a projected 38% increase in the number of people commuting between the two states. The 18-month study would include input from the Port Authority, the MTA, and NJ Transit. If the New Jersey subway extension were to be constructed, it could complement the Gateway Project, which might become overcrowded by 2040.

1929–1939 plans

Before unification in 1940, the government of New York City made plans for expanding the subway system, under a plan referred to in contemporary newspaper articles as the IND Second System (due to the fact that most of the expansion was to include new IND lines, as opposed to BMT/IRT lines). 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. Cost is only for construction, and does not include land acquisition or other items.

{| class="wikitable"

!Line

!Streets

!From

!To

!Tracks

!Route miles

!Track miles

!Cost

!Notes

!colspan=9|Manhattan

|rowspan=2|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||1.34||4.68||$11,300,000||subway

|Second Avenue||Houston Street||Harlem River||4 to 61st Street 6 to 125th Street 4 to Harlem River||6.55||32.84||$87,600,000||subway

|61st Street Line||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

|colspan=5|Manhattan subtotal||11.87||45.48||$126,800,000||

!colspan=9|Bronx

|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

|White Plains Road Line||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

|colspan=5|Bronx subtotal||19.04||51.32||$77,000,000||

!colspan=9|Brooklyn

|Broadway Branch Line (Rockaway Line)||Broadway||East River||Havemeyer Street at South Fourth Street||2||rowspan=2|3.16||rowspan=2|13.5||rowspan=2|$34,800,000||subway

|rowspan=4|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||subway

|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 Street||4||1.34||5.36||$14,300,000||subway

|Fulton Street Line||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

|colspan=5|Brooklyn subtotal||16.84||61.52||$114,500,000||

!colspan=9|Queens

|rowspan=3|Rockaway Line||Myrtle Avenue – Central Avenue||Palmetto Street||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 Line (Rockaway Line Extension)||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; terminal station partially-built as part of Roosevelt Avenue-Jackson Heights station, with short trackways leading to the spur.

|Brinckerhoff - Hollis Avenue Line (Fulton Street Line Extension)||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 (now Linden Boulevard)||4 to Van Wyck Boulevard 2 to Foch Boulevard||5.23||13.92||$9,500,000||elevated

|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

|colspan=5|Queens subtotal||52.37||136.49||$119,100,000||

|colspan=5|Total||100.12||294.81||$438,400,000||

Other plans during the same time

Revised 1932 plan

The IND expansion plan was revised in 1932. It differs from the 1929 plan, but there are , of which are in Manhattan, in the Bronx, in Brooklyn, and in Queens. It would include a new 34th Street crosstown line, a Second Avenue Subway line, a connection to the New York, Westchester and Boston Railway, and extensions of the IRT Nostrand Avenue Line, IRT Flushing Line, and BMT Astoria Line. It would have created a subway loop bounded by 2nd and 10th Avenues, and 34th and 125th Streets. This plan included no extensions to Whitestone, Queens, however, with the plan to instead serve more densely populated areas such as Astoria and the Roosevelt Avenue corridor.

The plan would also take over the local tracks of the New York, Westchester and Boston Railway, and the Rockaway Beach Branch of the Long Island Rail Road.

(1939 plan) A line splitting from the South Brooklyn (Culver) Line at Fort Hamilton Parkway or Church Avenue, and running under Fort Hamilton Parkway to 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 1923 to serve the BMT Fourth Avenue Line, but was not completed.
(1940 plan, revised 1945) The IND Fulton Street Line would connect to what is now the IND Rockaway Line. A branch of the IND Fulton Street Line would run to a stub-end terminal at 105th Street. The line, east of Euclid Avenue, would be four tracks until Cross Bay Boulevard, where the two branches would split.
(unknown date) A third two-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).
(unknown date) A four-track subway under Bedford Avenue in Brooklyn connecting to the Worth Street Subway and Second Avenue Subway.

An earlier plan in 1920 had an even more expansive plan, with several dozen subway lines going across all five boroughs.

Provisions for new lines

thumb|250px|right|At [[East Broadway (IND Sixth Avenue Line)|East Broadway on the IND Sixth Avenue Line (shown), part of a two-track station was built for the IND Worth Street Line under East Broadway, above the existing line. The indent for the never-built line is seen at the top of the picture, crossing the ceiling.]]

thumb|250px|The [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street subway station has two island platforms split across two levels. Their northern sides were walled off until the first phase of the Second Avenue Subway was opened. This is the station's lower level.]]

The following provisions were made for connections and transfers to the new lines. It is of note that only four of these provisions were completed.

At Second Avenue on the IND Sixth Avenue Line, the ceiling drops at the west end. Above the ceiling is a provision for a four-track IND Second Avenue Line. The future Second Avenue Line will not utilize this provision; it will instead be built under the station, if a transfer station is ever built.
At East Broadway on the IND Sixth Avenue Line (under Rutgers Street at this station), part of a two-track station was built for the IND Worth Street Line under East Broadway, above the existing line. Most of the constructed portion is now part of the mezzanine, with a small unused section blocked by a door.
At Broadway on the IND Crosstown Line, traces of passageways are visible going towards a six-track station on the line to Utica Avenue, as well as a stair to an upper mezzanine on top of the unfinished station.
At Utica Avenue on the IND Fulton Street Line, a four-track station above can be seen in the ceiling of the existing station. This portion of the Utica Avenue Line was built with the construction of the Fulton Street Line. Ramps were built from the mezzanine to the platforms because the normal vertical distance of ten feet from the mezzanine floor to the platforms was increased to 25 feet in anticipation of the Utica Avenue Line. 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.
Hillside Avenue considerably widens between 218th Street and 229th Street in Queens Village, and gains a very wide median. This section was widened in the 1930s to accommodate construction of the proposed eastern terminus of the IND Queens Boulevard Line at Springfield Boulevard and Rocky Hill Road (Braddock Avenue) and to accommodate an underpass for Hillside Avenue underneath Springfield Boulevard and Braddock Avenue. Six station entrances would have been provided at Springfield Boulevard and Braddock Avenue. The station would have stretched as far east as 88th Avenue. The two tracks would have continued to 229th Street.
The center tracks on the IND Sixth Avenue Line dead end at the curve from Houston Street to Essex Street; these were planned to continue through a new East River tunnel to Williamsburg and south to the proposed Utica Avenue line towards Sheepshead Bay.
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, connecting to the Second Avenue Subway.
The Lexington Avenue–63rd Street subway station has two island platforms, which were originally built with now-demolished walls on their northern sides. The platforms were designed to provide a cross-platform interchange to the Second Avenue Subway.
The upper level relay tracks east of 179th Street on the IND Queens Boulevard Line were intended to continue toward Floral Park, and the tunnel is designed to allow for such a future extension.
The relay tracks east of Euclid Avenue on the IND Fulton Street Line were intended to continue toward Cambria Heights in Queens.
The Nevins Street station on the IRT Eastern Parkway Line has an unused center trackway and an unused lower level intended for expansion into northern or southern Brooklyn.
South of the 36th Street station on the BMT Fourth Avenue Line, there are three trackways that diverge from the line at a flying junction. These trackways end under the eastern curb of Fourth Avenue.
The BMT Fourth Avenue Line has provisions for two more tracks south of 59th Street, where the line becomes double-tracked:
There are four trackways on the BMT Fourth Avenue Line bridge over the LIRR Bay Ridge Branch despite the fact that only the northernmost two tracks are in use.
The 86th Street station on the BMT Fourth Avenue Line appears to have "escapes" in the wall bricked over along the Manhattan-bound track, for the never-built fourth tracks.
There are bellmouths and space for two additional trackways (for a total of six) on the BMT Fourth Avenue Line south of 59th Street. These provisions were for the Staten Island Tunnel, which would have intersected with the line south of 59th Street.

{|cellspacing=0 cellpadding=3

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" rowspan=3 width=50 valign=top|Level 1

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=100|Northbound

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=390|← Broadway line westbound

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 0px gray;"|Southbound

|style="border-bottom:solid 0px gray;"|← Broadway line eastbound →

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" rowspan=10 width=50 valign=top|Level 2

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=100|Northbound

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=390|← Utica Avenue express to Sixth Avenue

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|Northbound

|← Flushing/Utica Avenues local (termination platform)

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 1px gray;"|Northbound

|style="border-bottom:solid 1px gray;"|← Flushing Avenue express to Eighth Avenue

|Southbound

|← Flushing Avenue express from Eighth Avenue →

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|Southbound

|← Flushing/Utica Avenues local →

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 0px gray;"|Southbound

|style="border-bottom:solid 0px gray;"|← Utica Avenue express from Sixth Avenue →

|style="border-bottom:solid 1px gray;border-top:solid 1px gray;" rowspan=4 width=50 valign=top|Level 3

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=100|Southbound

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=390|← Utica Avenue local →

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 1px gray;text-align:center;" colspan=2|Island platform

|style="border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 1px gray;"|Southbound

|style="border-bottom:solid 1px gray;"|← Utica Avenue local →

Note: The locals would have short-turned here. There would have been two tunnels under the East River: East Houston Street and Grand Street.

Another plan for the South Fourth Street shell was simpler (and was the plan that was partially completed):

{|cellspacing=0 cellpadding=3

|style="border-bottom:solid 1px gray;border-top:solid 1px gray;" rowspan=10 width=50 valign=top|Level 1

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=100|Northbound

|style="border-bottom:solid 0px gray;border-top:solid 1px gray;" width=390|← Flushing Avenue express to Eighth Avenue

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|Northbound

|← Utica Avenue express to Sixth Avenue via East Houston Street

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 1px gray;"|Northbound

|style="border-bottom:solid 1px gray;"|← Utica Avenue local to Sixth Avenue via Stanton Street

|Southbound

|← Utica Avenue local from Sixth Avenue via Stanton Street →

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|Southbound

|← Utica Avenue express from Sixth Avenue via East Houston Street →

|style="border-top:solid 2px black;border-right:solid 2px black;border-left:solid 2px black;border-bottom:solid 2px black;text-align:center;" colspan=2|Island platform

|style="border-bottom:solid 1px gray;"|Southbound

|style="border-bottom:solid 1px gray;"|← Flushing Avenue express from Eighth Avenue →

Note: The Flushing Avenue local would have diverged off to the IND Crosstown Line. There would have been three tunnels under the East River: East Houston Street, Stanton Street, and Grand Street.

The Utica Avenue station shell, if complete, would be in the standard local-express-express-local platform configuration.

The Jackson Heights–Roosevelt Avenue shell, a two-trackbed island-platformed station, would have been for local trains terminating at the station. Express trains would have stopped at the lower level (IND Queens Boulevard Line) platforms.

-->

1940–1999 plans

After World War II and up until the late 1990s, the New York City Subway did not expand much. Only 28 stations opened in that time, compared to the remaining 393 stations, which opened from the 1880s to before World War II. As such, there have been many plans to expand the system during this time period.

1938–1940

thumb|right|300px|The [[Staten Island Tunnel, started in 1912, was to be complete as per the 1940 plan.]]

thumb|right|300px|The [[IND_Culver_Line#Culver_Ramp|Culver Ramp was the only completed Brooklyn proposal put forth in 1940. It opened in 1955.]]

The New York City Board of Transportation revised its plans for subway expansion, and released them in 1938 and 1940.

The remnant of the IRT Ninth Avenue Line at 155th Street would connect with the IRT Lenox Avenue Line, giving riders of the Jerome Avenue Line service to Manhattan's West Side. The first phase would end the line at East 139th Street. The Main Line and its connections to other subway lines was to have cost $213.95 million, while the future Bronx extension would have cost $130.16 million.
An extension of the IRT Lenox Avenue Line would have been built so it could connect with the IRT Ninth Avenue Line.
Two express tracks would be built on the IND Sixth Avenue Line between West 9th Street and West 31st Street for $19.27 million. This was viewed as a requirement for a Second Avenue Line.
The Seventh Avenue Line Extension would extend the Broadway Line north from 59th Street via a tunnel under Central Park to 72nd Street, before turning east into Queens via Northern Boulevard to Jackson Heights. It was to have been built as a two-track and four-track line, and it would have cost $89 million. The second phase would extend the line as a two-track line along Corona Avenue and Horace Harding Boulevard from Jackson Heights to Marathon Parkway. A storage yard would be built. This phase would have cost $51.82 million. A connection between the new line and the Crosstown Line was to have been built at 23rd Street (Ely Avenue) for $10.95 million.
The provision at Van Wyck Boulevard for a future line would be completed, and a new two-track line would be built to Rockaway Boulevard. In 1951, these relay tracks east of Euclid Avenue were still planned to go as far as 105th Street, with a connection to the IND Rockaway Line east of Cross Bay Boulevard. If the line were ever built, Pitkin Avenue would have been routed to the east rather than to the southeast at 80th Street, and Linden Boulevard between Conduit and Rockaway Boulevards would have been built to facilitate the line.
A new IND line would run from the Lower East Side to Avenue U in Brooklyn, with a possible extension to Floyd Bennett Field.
A connection between the BMT Franklin Avenue Line and the IND Crosstown Line would be built through the construction of a line under Lafayette Avenue.

A rail link to LaGuardia Airport was proposed in 1943, when the city Board of Transportation proposed an extension of the BMT Astoria Line (currently served by the ) from its terminus at Ditmars Boulevard. The line would have run along Ditmars Boulevard, and would have cost $10.5 million.

A branch of the BMT Fourth Avenue Line at 59th Street under the Narrows to Saint Nicholas Street and Grent Street in Staten Island.
A branch of the IND Fulton Street Line running via Utica Avenue to Avenue U.
An extension of the IRT Nostrand Avenue Line from Flatbush Avenue to Voohries Avenue.
A line branching off of the IND Crosstown Line running via Franklin Avenue connecting with the BMT Brighton Line. This would have replaced the BMT Franklin Avenue Line.
The extension of the IND Fulton Street Line to Euclid Avenue would continue to be built, and would be extended to 229th Street and Linden Boulevard.
The completion of the Culver Ramp, connecting the IND Culver Line with the BMT Culver Line.
A branch of the IND Culver Line running via Tenth Avenue and Fort Hamilton Parkway to 86th Street, with a connection to the BMT West End Line. West End service would run via the Culver Line and would alleviate congestion at DeKalb Avenue Junction. In order to provide access to the BMT Fourth Avenue Line, the Culver Shuttle would be extended to 36th Street.

Even though the Board of Transportation did not approve these ideas, they were still proposed.

A line branching off of the IND Eighth Avenue Line running via Worth Street and East Broadway and running under the East River to Driggs Avenue.
A new trunk line built along Second Avenue with a connection at Court Street to the IND Fulton Street Line.
Lines in Queens to the Rockaways, LaGuardia Airport, Idlewild Airport (now called JFK Airport), College Point, Bayside, Little Neck, Douglaston, Saint Albans and Bellerose.

In 1949, the Board of Transportation issued a $504 million plan to increase capacity on several subway lines through the construction of a new trunk line under Second Avenue.

The rebuilding of DeKalb Avenue that would remove the bottleneck and increase capacity by 18 tph. The station platforms, and third rail would have had to be adjusted as they were put in place for the narrower IRT trains. The line was built with this conversion in mind, however. Westchester Yard would have been expanded to accommodate the additional trains added to the line. Since trains to the Pelham Line would no longer use the Lexington Avenue Line, there would be additional capacity for trains to run via the IRT White Plains Road Line and the IRT Jerome Avenue Line. Improved service on the Pelham Line was projected to stimulate growth in the areas of the East Bronx served by the line. The East Bronx was seen to have great potential for industrial growth and other areas suitable for development as residential and recreational areas.
The rebuilding of DeKalb Avenue that would increase capacity by 18 tph.
IND Sixth Avenue Line express tracks
A four-track Second Avenue Subway between 149th Street, the Bronx, to Grand Street, Manhattan.
Connections would be made to the BMT Nassau Street Line, the Williamsburg Bridge, and the Manhattan Bridge. The Sixth Avenue Line would also be connected to the Williamsburg and Manhattan Bridges.
The Rockaway Beach Branch of the Long Island Rail Road (LIRR) would be acquired by the City and an embankment would be created with two bridges for the right-of-way over Jamaica Bay. To provide a connection to the rest of the subway system, a track connection would be built to the IND Fulton Street Line.
The Rockaway Beach Branch would run alongside the LIRR main line tracks as a super-express bypass. Once in Woodside, the line would go underground running under Sunnyside Yards and Long Island City to the East River. It would then go under the East River and 76th Street in Manhattan to the Second Avenue Line.
The bypass would also have a connection to the LIRR's Port Washington Branch with subway service running to Bayside.
Connections to the IRT Pelham Line at Third Avenue–138th Street and to the IRT White Plains Road Line at Third Avenue–149th Street.

On September 13, 1951, the Board of Estimate approved a plan put forth by the New York Board of Transportation that would cost $500 million. Many expansions were planned:

A six-track Second Avenue Subway between 149th Street, the Bronx, to Grand Street, Manhattan. This line would handle 68 trains per hour (tph) (34 tph on the express tracks and 34 tph on the local tracks).
The construction of the Nostrand Avenue extension to Avenue U. It would have cost $51.7 million.
A Second Avenue trunk line, which would have allowed 34 more trains to midtown per hour.

1962–1963

In July 1962, the NYCTA announced that it had asked the city for money to build a $190 million high-speed, non-stop subway line from Midtown to the Bronx. The line would have only operated during rush hours. It was estimated that if the funds were given to the project, it would be completed in 1970. The line would be a two-track line running from 59th Street between Fifth and Seventh Avenues to the Bronx, running under Central Park. Running non-stop for 6.5 miles, it would have been the longest continuous run in the subway system. The line, on its southern end, would connect to the BMT Broadway Line at Seventh Avenue near 59th Street and to the IND Sixth Avenue Line near 58th Street and Sixth Avenue.

The line would then run through a deep tunnel under Central Park until 110th Street. There would be provisions for a future crosstown line under 76th Street to Queens. The line would then turn east and run along Madison Avenue to 138th Street. One branch would connect to the express track of the IRT Pelham Line, which would be converted to accommodate larger B Division trains. In the morning rush hour, trains from Pelham Park would only make express stops. A new stop would be built at 138th Street and Grand Concourse where transfers would have been available to the IRT White Plains Road and IRT Jerome Avenue Line trains.

The second branch would continue under the Grand Concourse until 161st Street where it would connect to the IND Concourse Line at 161st Street. This connection would allow for the diversion of Concourse Line express trains onto the new line, allowing for the addition of an equal number of trains to the IND Central Park West express service and provide relief to that line. The construction of this line was viewed as necessary to relieve the IRT Lexington Avenue Line.

In February 1963, the New York City Transit Authority issued a preliminary proposal for rapid transit expansion in the borough of Queens. The plan was designed to relieve congestion on the IRT Flushing Line and IND Queens Boulevard, to deal with expected population growth, and to provide service to areas of the borough without transit service. To expand service to other areas of the borough a new trunk line would be built to provide the necessary capacity. The planned extensions were expected to relieve crowding on the IRT Flushing Line by 22 percent and on the IND Queens Boulevard Line by 19 percent.

The first phase of the transit expansion would build a trunk line connecting the IND Queens Boulevard Line's local tracks at Steinway Street and Broadway using existing provisions with the IND Sixth Avenue Line and BMT Broadway Line in Manhattan. The new line would have run under 34th Avenue, a new tunnel under the East River, and 76th Street before turning south under Central Park. Connections would be made to the IND Sixth Avenue Line at 58th Street and to the BMT Broadway Line's stub tracks at 59th Street and Seventh Avenue. In Manhattan, there would have been a transfer connection to the 77th Street station on the IRT Lexington Avenue Line and a station in Central Park at 70th Street.

In May 1963, the New York City Planning Commission proposed the following in response to the NYCTA's proposal: They included:

The IND Second Avenue Line with connections to IRT Dyre Avenue Line at East 180th Street, and the IRT Pelham Line at Whitlock Avenue
A crosstown line under 34th Street from 12th Avenue to 1st Avenue
Archer Avenue Line to Springfield Boulevard branching off of the BMT Jamaica Line at 127th Street and off of the Queens Boulevard Line at bellmouths railroad north of the Van Wyck Boulevard station. There are stub-end tunnels east of the line's northern terminus, Jamaica Center–Parsons/Archer, on both levels, which extend past the station for possible future extensions.

The 63rd Street Lines are two lines also split between the BMT and IND. The short BMT line connects the express tracks of the BMT Broadway Line from 57th Street–Seventh Avenue to Lexington Avenue–63rd Street, where it now runs through to the Second Avenue subway. The IND line runs from the IND Sixth Avenue Line at 57th Street in Manhattan east under 63rd Street and the East River through the 63rd Street Tunnel to the IND Queens Boulevard Line in Queens. There is a stub-end tunnel at the northern terminus of the IND line that is intended for the Queens super-express bypass.

1970s

In Lower Manhattan, plans were made for the following:

A new terminal for IRT Seventh Avenue locals to South Ferry
A track connection between the Hudson Terminal (now World Trade Center) on the IND Eighth Avenue Line and Cortlandt Street on the BMT Broadway Line, both in Manhattan.
RR trains would be discontinued south of City Hall, as the station would permanently become a terminal. The City Hall station is located one block east of Hudson Terminal. The segment between City Hall in Manhattan and Bay Ridge–95th Street would be replaced by two other services.
B Sixth Avenue express trains would be rerouted to the Eighth Avenue Lines, replacing the AA and CC Eighth Avenue locals. B trains would run south through the connection and continue through the Montague Street Tunnel and BMT Fourth Avenue Line, thereby replacing the RR between Cortlandt Street in Manhattan and 59th Street in Brooklyn.
JJ trains would operate via the Montague Street Tunnel and Fourth Avenue line, with an extension to Bay Ridge–95th Street.
A Second Avenue Subway would operate along Second Avenue in Manhattan, connecting New Jersey with both Queens and the Bronx.
T and Y would run the entire length of the Second Avenue line from New Jersey, then run toward Queens and the Bronx respectively.
EE trains would be rerouted onto the southernmost section of the subway into New Jersey via the BMT Broadway express tracks, which turn eastward toward the Manhattan Bridge. The EE would then diverge southward, merging with the Second Avenue main line.

1986

In 1986, the Regional Plan Association suggested extending the IRT Flushing Line across the Hudson River to the Meadowlands Sports Complex in East Rutherford, New Jersey.

In 1986, the MTA issued a study on expanding transit options on the west side of Manhattan. It was proposed to use the West Side Line viaduct (today's High Line), and various means of transportation were proposed, including monorail, passenger rail trains, or subway trains. It also proposed to extend the IRT Flushing or BMT Canarsie Lines ( and , respectively).

1990

In 1990, the MTA proposed a rail line connecting LaGuardia Airport and John F. Kennedy International Airport. The line would have operated over the Grand Central Parkway and the Van Wyck Expressway. There would be stations at Shea Stadium and Jamaica. The system was proposed to cost $2billion. The MTA estimated that the rail link would take 30minutes from Kennedy to LaGuardia, and the frequency of service would initially be every 15minutes. There would be a two-track alignment with one track for each direction, as well as at least two trains heading in each direction at all times. If the link were built, the average travel time from Manhattan to Kennedy would have been about 45minutes using the Long Island Rail Road, including transfers. To LaGuardia, the average travel time from the Grand Central station using the IRT Flushing Line would be 47minutes.

1998–99

thumb|right|300px|The AirTrain viaduct over [[Interstate 678|Van Wyck Expressway would have been used by the subway under the "MetroLink" plan.]]

In 1998, an extension of the BMT Astoria Line to LaGuardia Airport was planned, but the plan was canceled in 2003 following community opposition.

In 1999, the Regional Plan Association considered a full-length Second Avenue Subway from Broad Street to 125th Street, along with the LIRR East Side Access. It also planned the following extensions:

a Co-op City extension of the Second Avenue Subway via the Amtrak right-of-way through the northeast Bronx
a Grand Central Terminal spur of the Second Avenue Subway
a super-express bypass from the Atlantic Terminal via the LIRR Atlantic Branch
an extension to JFK Airport via the Van Wyck Expressway
an extension to Laurelton via the LIRR Atlantic Branch
a branch off the Second Avenue Subway at 14th Street to Avenue C, to merge with the IND Sixth Avenue Line at Essex Street
a connection to the BMT Nassau Street Line near Delancey Street
a super-express bypass of the Queens Boulevard Line from east of 21st Street–Queensbridge to east of Forest Hills–71st Avenue
a new interlocking at Prince Street to allow easy switching of trains between local and express tracks

The new set of extensions proposed by the RPA, dubbed "MetroLink", would make use of existing commuter rail infrastructure, so as to make it interoperable with the New York City Subway. Nine hundred fifty "Rx" hybrid railcars would be ordered, with yard expansions and new yards being built. MetroLink, consisting of 31 new metro stations (not counting three recycled commuter rail stations) and 19 new route‑miles of track () (not including existing commuter rail and then-under construction AirTrain JFK route miles) would have reduced the load on the IRT Lexington Avenue Line, the IRT Broadway–Seventh Avenue Line, and the IND Queens Boulevard Line. Two of these stations would be in Brooklyn, three in Queens, nine in the Bronx, and twenty in Manhattan. Five services would be run: The tunnels are actually long. A second station at 10th Avenue–41st Street was dropped from the plans in October 2007, but could be restored if funding can be found. The extension's opening had been delayed to June 2014, with the rest of the 34th Street station to open at the end of 2015.

Michael Horodniceanu, chief of MTA Construction Company, told The New York Times that complications in the installation of the inclined elevator would likely cause a further delay of about three months, bringing the opening date to very late summer or early fall of 2014. Further complications in February 2014 brought the projected date of the opening to November 2014, then to February 2015, then spring 2015, and to summer 2015. The station opened in September 2015.

As proposed under the RPA's Fourth Regional Plan, a second 7 Subway Extension would be built, serving 23rd Street before connecting with the existing 14th Street/Eighth Avenue station. This followed preliminary engineering and a final tunnel design completed by a joint venture between Aecom and Arup. Parsons Brinckerhoff was the construction manager of the project. This contract, and the full funding grant agreement with the Federal Transit Administration, which was received in November 2007, is for Phase I of the project, a new line between the existing 63rd Street Line and 96th Street and Second Avenue. The total cost of the line is expected to top $17billion.

A ceremonial ground-breaking for the Second Avenue Subway was held in April 2007. The tunnel boring machine (TBM) began digging the tunnels for Phase I in May 2010 and completed its excavations in September 2011. Phase I, consisting of of tunnel and three stations, was opened in January 2017. It cost $4.45 billion. A , $6 billion second phase is in planning; land acquisition for Phase 2 started in April 2022. , Phase 2 was set to open in early 2032.

The RPA's Fourth Regional Plan proposed two northward extensions. Phase 2B would be an extension of Phase 2 under 125th Street from Lexington Avenue to Broadway. Phase 2C would be a spur to Third Avenue–149th Street, connecting with the IND Concourse Line. In 1996, the Regional Plan Association conducted a study to determine the feasibility of the rail link. The original proposal would have terminated at Yankee Stadium.

The line in this proposal would have terminated at Hunts Point. Plans for the line date back to 1995.

Obstacles for the proposal include the proposed Cross-Harbor Rail Tunnel, the lack of electrification on the line, as well as the single-tracking in some parts of the line. The current iteration of the plan would have its northern terminus be Co-Op City South using the Hell Gate Branch. The LIRR Bay Ridge Branch and the New York Connecting Railroad have freight operating along them, and are regulated by the Federal Railroad Administration (FRA). FRA rules require a certain distance between freight and passenger trains that share rights-of-way, and as a result it is uncertain whether the right-of-way is wide enough or if more durable train cars are needed to be able to share the same tracks.

Interborough Express

In mid-October 2019, the MTA announced that it would study the feasibility of restoring passenger service on the Bay Ridge Branch portion of the route. In early January 2022, as part of her State of the State address New York governor Kathy Hochul announced that the state would move forward with the Bay Ridge Branch Line by conducting an environmental study on the Interborough Express (IBX), a corridor using the existing Bay Ridge Branch and Fremont Secondary from Bay Ridge, Brooklyn, to Jackson Heights, Queens. End-to-end travel times are expected to be less than 40 minutes, and weekday ridership is projected to be 115,000. The route would connect up to 17 subway lines and the Long Island Rail Road. The MTA indicated in September 2022 that it wanted to construct the IBX as a light rail line, and Hochul announced in January 2023 that the project would proceed as a light rail corridor.

Rockaway Line

right|thumb|250x250px|The LIRR [[Rockaway Beach Branch would need to be renovated in order to be reused.]]

The Long Island Rail Road (LIRR) abandoned the Rockaway Beach Branch in 1962; ever since it has been sought after for reactivation for train service. The line has not been reactivated due to local opposition, specifically the homeowners who live along the right-of-way. One group, QueensLink, wants the line to be reactivated between the 63rd Drive–Rego Park station on the IND Queens Boulevard Line to the north and the IND Rockaway Line to the south, providing a north-south connection in Queens. A second group would use the right-of-way as a linear park, known as the Queensway, a proposal inspired by the success of the High Line in Manhattan. A third group consists of homeowners who would have nothing done, keeping the line as is.

Talks of reactivating the line were publicly endorsed in February 2012 by Assemblymen Phillip Goldfeder and Michael G. Miller. Goldfeder commented "The commute for people here is only going to go from bad to worse. You can't talk about a convention center without talking about transportation." Goldfeder and Miller said they are not opposed to turning sections of the line into a park, but said people who live in the Rockaways, Ozone Park and other areas have no quick or easy way to get into Manhattan. The Genting Group, which operates Resorts World casino and have been asked to construct the convention center, are evaluating several plans to increase transportation access. Genting is committed to paying for part of the transportation improvements. Advocates of the Queensway, a proposed public park along the branch's route, are against resumption of rail service, stating that current bus service fills current transportation needs in the area. U.S. Representatives Hakeem Jeffries and Gregory Meeks added their support for the project in March 2013. Both representatives will push to allocate federal transportation subsidies to study a plan for restored passenger service.

The line would cost $1 billion, if built in its full length with a connection to the IND Queens Boulevard Line, and would stretch across , providing connections to several subway services as well as the LIRR. Another possible option would have Long Island Rail Road service restored with service to seven stations along the right-of-way, with service ending in Howard Beach. The line would serve upwards of 250,000 passengers per day and would provide access to JFK Airport from Midtown Manhattan. In February 2015, the Regional Plan Association suggested having some F trains, after running through the 63rd Street Tunnel, be rerouted to operate over the Lower Montauk Branch of the LIRR running through underserved Maspeth and Glendale and then meeting up with the Rockaway Beach Branch in Rego Park. The New York Daily News editorial board came out in support of this extension on February 21, 2017, detailing why this route is superior to Governor Andrew Cuomo’s plan for an AirTrain from LaGuardia to Willets Point.

Utica Avenue and Nostrand Avenue Lines

In April 2015, New York City Mayor Bill de Blasio announced a new plan for building a subway line under Utica Avenue in Brooklyn. Previous plans, most recently the Program for Action, had provisions for such a line. It would branch off from the IRT Eastern Parkway Line () at Crown Heights–Utica Avenue. The new line being proposed is part of de Blasio's "One New York" plan, which aims to improve transit, reduce emissions, and fight poverty. If built, the line would go to Flatbush Avenue, near Kings Plaza. Since the Metropolitan Transportation Authority had budget shortages , however, it is unclear how the line would be funded or built.

The MTA Board allocated $5 million for a feasibility study, the Utica Avenue Subway Extension Study, for this proposal in the MTA's 2015–2019 Capital Program. In August 2016, it was reported that the MTA was looking into an extension of the IRT Nostrand Avenue Line along Flatbush Avenue to Marine Park, which would allow trains to serve Kings Plaza. Both the Utica Avenue and Nostrand Avenue proposals for extensions to Kings Plaza have been proposed since the 1910s. because it was no longer viewed as a priority by the MTA. Planning resumed in April 2019 when New York City Transit joined city agencies in launching the Utica Avenue Transit Improvement Study. The study looked into a subway extension, improved bus rapid transit, and a new light rail line. Since the study occurred concurrently with the 2020 redesign of Brooklyn bus routes, the MTA decided to prioritize the Utica Avenue transit study, and the 2025-2044 Needs Assessment compares these options, determining bus rapid transit to be the most cost effective option.

In November 2017, the RPA suggested building both lines as part of its fourth plan. The Nostrand Line was envisioned as a three-stop extension to Avenue Z, while the Utica Line was planned as a five-stop spur to Kings Plaza. Under the RPA's plan, the Second Avenue Subway would be completed to its full length within Manhattan and then extended to the Bronx. The 7 Subway Extension would expand in scope, with the IRT Flushing Line being extended to 14th Street and Eighth Avenue. Ultimately, the plan included eight extensions with at least 40 stations in total.

, a potential extension of the BMT Broadway Line to Red Hook (to be served by the W train) is being evaluated as part of the MTA's 2025–2044 20-Year Needs Assessment.

Other proposals

, a potential extension of the IRT New Lots Line (to be served by the 3 train) to Spring Creek, Brooklyn, is being evaluated as part of the 2025–2044 20-Year Needs Assessment.

References

External links

NYCsubway.org – IND Second System
Abandoned Stations (A thorough treatment of the history of the abandoned subway stations)
IND Second System unfinished stations
JoeKorNer – IND Second System (including a plan for a line to Staten Island)
The Future NYC Subway (a thorough treatment of subway extensions that have been discussed, but never built)
Jim O'Grady. Lost Subways: Abandoned Stations & Unbuilt Lines
The Lost Subways of New York interactive map (WNYC)