View source for Second Avenue Subway

{{Short description|New York City Subway line}}
{{Redirect|IND Second Avenue Line|the former elevated railway line|IRT Second Avenue Line|the bus line that runs on Second Avenue|M15 (New York City bus)|the subway station at Houston Street|Second Avenue station}}
{{Good article}}
{{Use mdy dates|date=November 2018}}
{{Infobox rail line
| name            = Second Avenue Subway
| image           = {{rint|nycs|Q|size=50}}
| caption         = The Second Avenue Line is served by the [[Q (New York City Subway service)|Q]].<br />Limited service is also provided by the [[N (New York City Subway service)|N]] and [[R (New York City Subway service)|R]].<br />The [[T (New York City Subway service)|T]] ({{NYCS const|color|T}}) will serve the full line in the future if Phase 3 is completed.
| image_width     = 150px
| type            = [[Rapid transit]]
| system          = [[New York City Subway]]
| status          = Open from [[72nd Street station (Second Avenue Subway)|72nd Street]] to [[96th Street station (Second Avenue Subway)|96th Street]]<br />Phase 2 to [[125th Street station (IRT Lexington Avenue Line)|Harlem–125th Street]] in design
| locale          = [[Manhattan]], [[New York City]], [[United States]]
| start           = [[Harlem–125th Street (Second Avenue Subway)|Harlem–125th Street]]
| end             = [[Hanover Square (Second Avenue Subway)|Hanover Square]]
| stations        = 3 (13 more planned)
| open            = {{start date |2017|01|01}} (first phase)
| owner           = [[New York City|City of New York]]
| operator        = [[New York City Transit Authority]]
| daily_ridership = 45,367<ref name="ridership">{{NYCS const|riderref|weekday}}</ref>
| stock           =
| linelength      = {{convert|8.5|mi|km}}
| tracklength     = {{convert|17|mi|km}}<!--entire line is double tracked-->
| tracks          = 2
| gauge           = {{RailGauge|ussg}}
| electrification = 600 [[Volt|V]] [[Direct current|DC]] [[third rail]]
| speed           =
| character       = Fully underground
| elevation       =
| map             = {{Second Avenue Subway|inline=1}}
| map_state       = collapsed
}}

The '''Second Avenue Subway''' (internally referred to as the '''IND Second Avenue Line''' by the [[Metropolitan Transportation Authority|MTA]] and abbreviated to '''SAS''') is a [[New York City Subway]] line that runs under [[Second Avenue (Manhattan)|Second Avenue]] on the [[East Side (Manhattan)|East Side]] of [[Manhattan]]. The first phase of this new line, with three new stations on Manhattan's [[Upper East Side]], opened on January 1, 2017. The full Second Avenue Line (if it will be funded) will be built in three more phases to eventually connect [[Harlem–125th Street (Second Avenue Subway)|Harlem–125th Street]] in [[East Harlem]] to [[Hanover Square (Manhattan)|Hanover Square]] in Lower Manhattan. The proposed full line would be {{convert|8.5|mi}} and 16 stations long, serve a projected 560,000 daily riders, and cost more than $17 billion.

The line was originally proposed in 1920 as part of a [[Proposed expansion of the New York City Subway#1929–1939 plans|massive expansion]] of what would become the [[Independent Subway System]] (IND). In anticipation of the Second Avenue Subway being built to replace them, parallel [[IRT Second Avenue Line|elevated lines along Second Avenue]] and [[IRT Third Avenue Line|Third Avenue]] were demolished in 1942 and 1955, respectively, despite several factors causing plans for the Second Avenue Subway to be cancelled. Construction on the line began in 1972 as part of the [[Program for Action]]. It was halted in 1975 because of [[New York City 1970s fiscal crisis|the city's fiscal crisis]], leaving only a few short segments of tunnels completed. Work on the line restarted in April 2007 following the development of a financially secure construction plan. The first phase of the line, consisting of the [[96th Street station (Second Avenue Subway)|96th Street]], [[86th Street station (Second Avenue Subway)|86th Street]] and [[72nd Street station (Second Avenue Subway)|72nd Street]] stations, as well as {{convert|1.8|mi|km|abbr=on}} of tunnel, cost $4.45&nbsp;billion. A {{convert|1.5|mi|km|adj=on}}, $6&nbsp;billion second phase from 96th to 125th Streets is almost ready to start construction {{as of|2024|lc=y}}.

Phase 1 is served by the [[Q (New York City Subway service)|Q]] train at all times and limited rush-hour [[N (New York City Subway service)|N]] and [[R (New York City Subway service)|R]] trains. Phase 2 will extend the line's northern terminus from 96th Street to Harlem–125th Street. Both the Q and limited N services will be extended to 125th Street. Phase 3 will extend the line south from 72nd Street to Houston Street in Manhattan's Lower East Side. Upon completion, a new [[T (New York City Subway service)|T]] train will serve the entire line from Harlem to Houston Street. Phase 4 will again extend the line south from Houston Street to Hanover Square, maintaining the T designation for the entire line. The T will be colored {{NYCS const|color|T}} since it will use the Second Avenue Line through [[Midtown Manhattan]].

==Extent and service==
Services that use the Second Avenue Line through Midtown Manhattan are to be colored {{NYCS const|color|T}}.<ref name="nyt20110822"/> The following services use part or all of the Second Avenue Line:<ref>{{NYCS const|serviceguide}}</ref><ref name="program201608">{{cite web |url=https://progressiveaction.files.wordpress.com/2016/08/sub-division-b-general-distribution-fall-2016-wp-book.pdf |title=SUB-DIVISION B TRAIN OPERATOR/CONDUCTOR ROAD & NON-ROAD WORK PROGRAMS IN EFFECT: NOVEMBER 6, 2016 |date=July 29, 2016 |website=progressiveaction.info |publisher=New York City Transit |access-date=August 19, 2016 |archive-date=October 10, 2016 |archive-url=https://web.archive.org/web/20161010184526/https://progressiveaction.files.wordpress.com/2016/08/sub-division-b-general-distribution-fall-2016-wp-book.pdf |url-status=live }}</ref>

{| class="wikitable"
! &nbsp;
! Time period
! Section of line
|-
| align=center | {{rint|newyork|N}}
| Rush hour (limited southbound service only)<ref name="N Timetable">{{NYCS const|timetable|n}}</ref>
|rowspan=3<!--3-->| Phase<!--s--> 1 <!-- and 2-->
|-
| align=center | {{rint|newyork|Q}}
| All times<ref name="Q Timetable">{{NYCS const|timetable|q}}</ref>
|-
| align=center | {{rint|newyork|R}}
| Rush hour (one northbound trip)<ref name="R Timetable">{{NYCS const|timetable|r}}</ref>
<!-- remove comment if the T ever opens
|-
| align=center | {{rint|newyork|T}}
| All times
| Entire line
-->
|}
[[File:Second Avenue Subway Map vc.jpg|upright|thumb|alt=A proposed map of the Manhattan portions of the Q and T trains upon completion of Phase 4. The T is planned to eventually serve the full line between Harlem–125th Street and Hanover Square, and the Q will serve the line between 72nd Street and Harlem–125th Street.|A proposed map of the Manhattan portions of the Q and T trains upon completion of Phase 4. The T is planned to eventually serve the full line between [[Harlem–125th Street (IND Second Avenue Line)|Harlem–125th Street]] and [[Hanover Square (Manhattan)|Hanover Square]], and the Q will serve the line between [[72nd Street (Second Avenue Subway)|72nd Street]] and Harlem–125th Street.]]

===Phase 1===
Phase 1 of the Second Avenue Line opened in January 2017.<ref name=":1"/><ref name=":41"/><ref name=":42"/> It runs under Manhattan's Second Avenue from 65th Street to 105th Street,<ref name=tracks/> with stations at [[72nd Street (IND Second Avenue Line)|72nd Street]], [[86th Street (IND Second Avenue Line)|86th Street]], and [[96th Street (Second Avenue Subway)|96th Street]]. It is double-tracked along its entire length, with tracks in parallel tubes bored by [[tunnel boring machines]], and central [[island platform]]s at all stations.<ref name="tracks">{{NYCS const|trackref|trackbook}}</ref><ref name=":45" /><ref name="fta pdf" /> North of 96th Street, both tracks continue as storage tracks until they end at 105th Street.<ref name="tracks" /><ref>{{cite web |url=http://web.mta.info/capital/sas_pdf/SAS%20Newsletter%20Feb%202013%2096th_Final.pdf |title=96th Street Station Area |publisher=Second Avenue Subway Newsletter |date=February 2013 |access-date=June 9, 2013 |archive-date=October 24, 2016 |archive-url=https://web.archive.org/web/20161024220731/http://web.mta.info/capital/sas_pdf/SAS%20Newsletter%20Feb%202013%2096th_Final.pdf |url-status=live }}</ref>

As part of Phase 1, the Second Avenue Subway connects to the BMT Broadway Line using an existing connection via the 63rd Street Line.<ref name=tracks/><ref name="fta pdf" /><ref name=":21"/> The Q, as well as limited rush-hour N and R, operates northward from [[57th Street–Seventh Avenue (BMT Broadway Line)|57th Street–Seventh Avenue]] on the Broadway Line, curving east under [[Central Park]] on the 63rd Street Line.<ref name="NY1W">{{cite web|url=http://www.ny1.com/nyc/all-boroughs/news/2016/02/19/w-train-is-coming-back-.html|title=MTA Confirms W Train is Coming Back|last=Martinez|first=Jose|date=February 19, 2016|website=ny1.com|publisher=Time Warner Cable|access-date=February 19, 2016|archive-date=July 3, 2018|archive-url=https://web.archive.org/web/20180703190914/http://www.ny1.com/nyc/all-boroughs/news/2016/02/19/w-train-is-coming-back-.html|url-status=live}}</ref><ref>{{cite press release|title=MTA Advances Work On Second Avenue Subway Service|date=February 19, 2016|publisher=Metropolitan Transportation Authority|url=http://www.mta.info/press-release/nyc-transit/mta-advances-work-second-avenue-subway-service|access-date=February 19, 2016|archive-date=February 22, 2016|archive-url=https://web.archive.org/web/20160222005540/http://www.mta.info/press-release/nyc-transit/mta-advances-work-second-avenue-subway-service|url-status=dead}}</ref> Broadway Line trains then stop at [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street]] with a [[cross-platform interchange]] to the {{NYCS|F}} train before merging with the Second Avenue Line near 65th Street. This connection also connects to the Sixth Avenue Line allowing for trains from the Sixth Avenue line to access the Second Avenue Subway, though this connection has been unused in regular service {{as of|April 2020||lc=y|alt=since April 2020<!--when the M train stopped using the connection-->}}. The northbound 63rd Street Connector track dips below the level of Phase 3's planned tunnels, providing for a future [[flying junction]] between the connector and the rest of the Second Avenue Line.<ref name="fta pdf" />

===Plans for expansion===
The long-term plans for the Second Avenue Subway involve digging {{convert|8.5|mi|km}} of new tunnels north to [[Harlem–125th Street (Second Avenue Subway)|Harlem–125th Street]] in Harlem and south to [[Hanover Square (Manhattan)|Hanover Square]] in the [[Financial District, Manhattan|Financial District]] of [[Lower Manhattan]].<ref name="fta pdf" /> The entire line would also be double-tracked,<ref name=":45" /><ref name="feis2-05" /> except for a tentatively four-tracked segment between 21st and 9th Streets, including the [[14th Street (IND Second Avenue Line)|14th Street]] station, with the outer two tracks used to store trains.<ref name="feis2-05" /> After Phase 4 is completed, the residents of [[East Harlem]] and the [[Upper East Side]] will have [[mass transit]] service down both [[Second Avenue (Manhattan)|Second Avenue]] and [[Broadway (Manhattan)|Broadway]] to the [[Financial District, Manhattan|Financial District]] (the latter via transfer to Broadway local trains), as well as across the [[Manhattan Bridge]] to [[Brooklyn]] via the Q train.<ref name="fta pdf" /><ref name=":21">{{cite web |url=http://web.mta.info/capital/sas_docs/feis/chapter05b.pdf |title=Second Avenue Subway Final Environmental Impact Statement (FEIS): Chapter 5B: Transportation—Subway and Commuter Rail |date=May 2004 |website=mta.info |publisher=Metropolitan Transportation Authority |access-date=December 17, 2016 |archive-date=October 5, 2018 |archive-url=https://web.archive.org/web/20181005210638/http://web.mta.info/capital/sas_docs/feis/chapter05b.pdf |url-status=live }}</ref>{{rp|5B·19}}<ref name="Q Timetable" />

An additional two-track connection is planned at around 63rd Street that will connect the Lower Manhattan-bound tracks on the Second Avenue Line with the Queens-bound tracks on the [[IND 63rd Street Line]], using existing bellmouths at 63rd Street and First Avenue. Current plans do not call for it to be used by regular service. Instead, it would be used for moving out-of-service trains.<ref name="MTA-SASFEISCh2"/>{{rp|7}} The connection would allow for trains to run from the Financial District to Queens if the capacity of the IND Queens Boulevard Line were increased, or if the Queens Bypass were built.<ref name=":7" />

Service from Queens via the 63rd Street Tunnel would allow for the full capacity of the line south of 63rd Street to be used. The whole line will be designed to accommodate 30 trains per hour, with the exception of the terminal at Hanover Square, which will only be able to handle 26 trains per hour (TPH). The portion north of 63rd Street is planned to have 14 TPH on the Q and 14 TPH on the T, for a combined 28 trains per hour on both routes. South of there, only 14 TPH on the T are planned, although 12 additional TPH could be provided in the future via the 63rd Street Tunnel.<ref name=":21" />{{rp|5B·20}} The 2004 plans for the Second Avenue Subway include the construction of short track segments to allow a future extension north under Second Avenue past 125th Street to the Bronx, as well as an extension south to Brooklyn.<ref name="MTA-SASFEISCh2"/>{{rp|11, 12}}

In order to store the 330 additional subway cars needed for the operation of the line, storage tracks would be built between 21st Street and 9th Street along the main alignment. The [[36th–38th Street Yard]] in [[Sunset Park, Brooklyn]], would also be reconfigured.<ref name="MTA-SASFEISCh2"/>{{rp|26}}

The Second Avenue Subway is [[New York City Subway chaining|chained]] as "S".<ref name=":7" /> The track map in the 2004 FEIS showed that all stations, except for 125th Street, would have two tracks and one island platform.<ref name="feis2-05">{{cite web |url=http://web.mta.info/capital/sas_docs/feis/figure2-05.pdf |title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Figure 2-4 Track Diagram, South of 55th Street |date=May 2004 |website=mta.info |publisher=Metropolitan Transportation Authority |access-date=August 7, 2016 |archive-date=July 10, 2015 |archive-url=https://web.archive.org/web/20150710124313/http://web.mta.info/capital/sas_docs/feis/figure2-05.pdf |url-status=live }}</ref><ref name=":45">{{cite web |url=http://web.mta.info/capital/sas_docs/feis/figure2-04.pdf |title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Figure 2-4 Track Diagram, North of 55th Street |date=May 2004 |website=mta.info |publisher=Metropolitan Transportation Authority |access-date=August 7, 2016 |archive-date=September 25, 2015 |archive-url=https://web.archive.org/web/20150925070641/http://web.mta.info/capital/sas_docs/feis/figure2-04.pdf |url-status=live }}</ref> 72nd Street and 125th Street were conceived as three-track, two-platform stations. 72nd Street was eventually scaled down to a two-track, center island platform station in order to reduce costs,<ref name="CB8">{{cite web |url=http://web.mta.info/capital/sas_docs/CB8%20presentation%2006-17-08.pdf |title=Community Board 8 Second Avenue Subway Task Force |website=mta.info |publisher=[[Metropolitan Transportation Authority]] |archive-url=https://web.archive.org/web/20140408215418/http://web.mta.info/capconstr/sas/documents/CB8%20presentation%2006-17-08.pdf |archive-date=April 8, 2014 |date=June 17, 2008 |access-date=December 18, 2016 |url-status=live}}</ref><ref>{{cite web |url=http://web.mta.info/capital/sas_docs/ea/01%20Purpose%20and%20Need.pdf |title=Supplemental Environmental Assessment to the Second Avenue Subway Final Environmental Impact Statement: 72nd and 86th Street Station Entrance Alternatives Chapter 1: Purpose and Need |date=October 29, 2009 |website=mta.info |publisher=Metropolitan Transportation Authority |access-date=August 9, 2016 |archive-date=August 18, 2016 |archive-url=https://web.archive.org/web/20160818083217/http://web.mta.info/capital/sas_docs/ea/01%20Purpose%20and%20Need.pdf |url-status=live }}</ref> A three-tracked 72nd Street station would have allowed trains from the Broadway Line to short-turn (reverse) without interfering with mainline service on Second Avenue, as well as provided additional operational flexibility for construction work and non-revenue moves.<ref name="AppendixB" />{{rp|20}} In July 2018, the 125th Street station was also scaled down to a two-track, one-platform station because the MTA had ascertained that two-tracked terminals would be sufficient to handle train capacities, and that building a third track would have caused unnecessary impacts to surrounding buildings.<ref name="MTA-SEASCh2"/>{{rp|13}}

==History==
{{main|History of the Second Avenue Subway}}

===Initial attempts===
[[File:2nd Avenue Subway Raised Ceiling by David Shankbone.jpg|thumb|right|alt=A large drop in the ceiling of the Second Avenue station on the Lower East Side; the unbuilt Second Avenue Subway was to pass through above the lower ceiling|A space above the [[Second Avenue (IND Sixth Avenue Line)|Second Avenue]] station through which the Second Avenue Subway was to have passed.{{refn|group=note|For context, see:
* {{cite web |title=Abandoned Stations: IND Second System unfinished stations |last=Brennan |first=Joseph |website=Columbia University |url=http://www.columbia.edu/~brennan/abandoned/indsecsys.html |date=2002 |access-date=July 27, 2017}}}}]]

After [[World War I]], the [[New York City Subway]] experienced a surge in ridership. By 1920, 1.3 billion annual passengers were riding the subway, compared to 523 million annual riders just seven years before the war. In 1919, the [[New York Public Service Commission]] launched a study at the behest of engineer Daniel L. Turner to determine what improvements were needed in the city's [[public transport]] system.<ref name="nycsub 1972">{{cite web |url=http://www.nycsubway.org/wiki/Second_Avenue_Subway:_The_Line_That_Almost_Never_Was |title=The Second Avenue Subway Line. . . the line that almost never was |year=1972 |publisher=New York City Transit Authority |access-date=September 30, 2015 |archive-date=October 1, 2015 |archive-url=https://web.archive.org/web/20151001063238/http://www.nycsubway.org/wiki/Second_Avenue_Subway:_The_Line_That_Almost_Never_Was |url-status=live }}</ref><ref name=":43">{{cite news |url=https://timesmachine.nytimes.com/timesmachine/1920/10/03/109800180.pdf |title=CITY'S GROWTH DISCOUNTED IN PLANS FOR ADDING 830 MILES OF TRACK TO RAPID TRANSIT SYSTEMS; Work to Cover Period of Twenty-five Years and Cost $350,000,000—New Lines and Extensions Would Provide for a Population of Nine Millions and Carry Five Billion Passengers |date=October 3, 1920 |newspaper=[[The New York Times]] |access-date=January 2, 2017 |issn=0362-4331 |archive-date=December 5, 2019 |archive-url=https://web.archive.org/web/20191205040236/https://timesmachine.nytimes.com/timesmachine/1920/10/03/109800180.pdf |url-status=live }}</ref><ref name="nyr20170213">{{cite magazine |last=Paumgarten |first=Nick |title=The Second Avenue Subway Is Here! |magazine=The New Yorker |date=February 6, 2017 |url=http://www.newyorker.com/magazine/2017/02/13/the-second-avenue-subway-is-here |access-date=February 24, 2017 |archive-date=February 25, 2017 |archive-url=https://web.archive.org/web/20170225053031/http://www.newyorker.com/magazine/2017/02/13/the-second-avenue-subway-is-here |url-status=live }}</ref> Turner's final paper, titled ''Proposed Comprehensive Rapid Transit System'', was a massive plan calling for new routes under almost every north-south Manhattan avenue, extensions to lines in [[Brooklyn]] and [[Queens]], and several crossings of [[the Narrows]] to [[Staten Island]].<ref name=":43" /><ref>{{Cite book|url=https://archive.org/details/reportbychiefeng00newy|title=Report by the chief engineer submitting for consideration a comprehensive rapid transit plan covering all boroughs of the city of New York|last=Turner|first=Daniel L.|date=January 1, 1920|publisher=New York : Office of Transit Construction Commissioner|via=archive.org}}</ref>{{Rp|22–25}} Among the plans was a massive trunk line under Second Avenue consisting of at least six tracks and numerous branches throughout Brooklyn, Queens, and [[the Bronx]].<ref name="nycsubway.org">{{cite web|url=http://nycsubway.org/wiki/IND_Second_System_-_1929_Plan|title=IND Second System 1929 Plan|publisher=nycsubway.org|access-date=March 25, 2016|archive-date=April 25, 2021|archive-url=https://web.archive.org/web/20210425204208/http://nycsubway.org/wiki/IND_Second_System_-_1929_Plan|url-status=live}}</ref> The [[IRT Second Avenue Line|Second]] and [[IRT Third Avenue Line|Third Avenue]] elevated lines were to be knocked down to make room for the 6-track subway.<ref name="raskin">{{Cite Routes Not Taken}}</ref>{{rp|203}} The paper was revised in January 1927.<ref name="nycsub 1972"/>

In September 1929, the [[New York City Board of Transportation|Board of Transportation of the City of New York]] (BOT) tentatively approved the expansion,<ref name=nyr20170213/> which included a Second Avenue Line with a projected construction cost of $98.9&nbsp;million (equivalent to ${{format price|{{inflation|US|98,000,000|1929}}}} in {{Inflation/year|US}}), not counting land acquisition. In the north, several spur lines in the Bronx would merge into a four-track [[trunk line]], crossing the [[Harlem River]] south to [[125th Street (Manhattan)|125th Street]]. There would be six tracks from 125th Street to a link with the [[IND Sixth Avenue Line]] at 61st Street, then four tracks from 61st Street to [[Chambers Street (Manhattan)|Chambers Street]], and two tracks from Chambers Street to Pine Street.<ref>{{cite news|url=https://timesmachine.nytimes.com/timesmachine/1929/09/22/91938390.pdf|title=OUR GREAT SUBWAY NETWORK SPREADS WIDER; New Plans of Board of Transportation Involve the Building of More Than One Hundred Miles of Additional Rapid Transit Routes for New York|last=Duffus|first=R.L.|date=September 22, 1929|work=The New York Times|access-date=August 14, 2015|archive-date=October 30, 2021|archive-url=https://web.archive.org/web/20211030145548/https://timesmachine.nytimes.com/timesmachine/1929/09/22/91938390.html?pdf_redirect=true&site=false|url-status=live}}</ref><ref name="nymag 20090724">{{cite magazine|url=http://nymag.com/daily/intelligencer/2009/07/the_tortured_history_of_the_se.html|title=The Long, Tortured History of the Second Avenue Subway|last=Jewler|first=Sam|date=July 24, 2004|magazine=The New Yorker|access-date=August 14, 2015|archive-date=August 2, 2015|archive-url=https://web.archive.org/web/20150802133914/http://nymag.com/daily/intelligencer/2009/07/the_tortured_history_of_the_se.html|url-status=live}}</ref>

The [[Great Depression]] began that year and the soaring costs of the expansion became unmanageable. Construction on the first phase of the IND was already behind schedule, and the city and [[New York (state)|state]] were no longer able to provide funding.<ref name="nycsubway.org"/> In 1930, the line was scaled down, with the line from 125th to [[Houston Street]]s to be complete by 1940, as well as a spur along [[34th Street (Manhattan)|34th Street]] to be done by 1948.<ref name="nymag 20090724"/><ref name="nycsub 1972"/><ref name=":28">{{Cite news|url=https://timesmachine.nytimes.com/timesmachine/1930/05/12/102133667.pdf|title=SUBWAY LOOP TO LINK 125TH AND 34TH STS.; Board Plans Line Under Those Thoroughfares to Tap North and South Bound Routes. TO RUN BENEATH 2D AVENUE Proposal in Tentative Form Is Approved by 34th Street Midtown Association. Plans in Tentative Stage. $800,000,000 Plans Ready Soon. SUBWAY LOOP TO LINK 125TH AND 34TH STS. Stress Loop's Advantages.|date=May 12, 1930|newspaper=The New York Times|access-date=December 22, 2016|issn=0362-4331|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226003453/https://timesmachine.nytimes.com/timesmachine/1930/05/12/102133667.html?pdf_redirect=true&site=false|url-status=live}}</ref> This scaled-down plan was postponed in 1931.<ref name="nycsubway.org"/> In 1932, the Board of Transportation modified the plan to further reduce costs, omitting a branch in the Bronx, and truncating the line's southern terminus to the [[Nassau Street Loop]].<ref name="nycsub 1972"/><ref name=raskin/>{{rp|204–205}}

Further revision of the plan and more studies followed. By 1939, construction had been postponed indefinitely, with only a short length being completed above the [[Second Avenue (IND Sixth Avenue Line)#Provisions for other lines|Second Avenue]] station. The Second Avenue Line was relegated to "proposed" status, and was number 14 on the Board of Transportation's list of important transportation projects.<ref name="nycsub 1972"/> The line was cut to two tracks with single northern branch through [[Throggs Neck, Bronx]], a connection to the [[BMT Broadway Line]] in Manhattan, and a continuation south onto the [[IND Fulton Street Line]] in Brooklyn via that line's [[Court Street (IND Fulton Street Line)|Court Street station]].<ref name="nycsubway.org"/><ref name=raskin/>{{rp|205}} The subway's projected cost went up to US$249&nbsp;million (equivalent to ${{format price|{{inflation|US|249e6|1941}}}} in {{Inflation/year|US}}). The United States' entry into [[World War II]] in 1941 halted all but the most urgent [[public works]] projects, delaying the Second Avenue Line once again.<ref name="nycsubway.org"/><ref name="nymag 20090724"/>

[[File:Second Avenue El - demolition.jpg|thumb|alt=Demolition of the structure of the Second Avenue elevated|The [[IRT Second Avenue Line|Second Avenue El]] was demolished in September 1942.<ref name=":0"/> This photo was taken at [[First Avenue (Manhattan)|First Avenue]] from 13th Street, looking south.]]

As part of [[History of the New York City Subway#Unification|the unification]] of the three subway companies that comprised the New York City Subway in 1940, elevated lines were being shut down all over the city and replaced by subways.<ref name=raskin/>{{rp|205–206}} The northern half of the [[Second Avenue Elevated]], serving the [[Upper East Side]] and [[East Harlem]], closed on June 11, 1940. The southern half, running through [[Lower Manhattan]], [[East Midtown]] and across the [[Queensboro Bridge]] to Queens, closed on June 13, 1942.<ref name=":0">{{cite web |url=http://mta.info/planning/sas/sas_history_1.htm |title=Second Avenue Subway Project – History |date=October 19, 2002 |website=mta.info |publisher=Metropolitan Transportation Authority |access-date=February 15, 2016 |archive-url=https://web.archive.org/web/20021019053707/http://mta.info/planning/sas/sas_history_1.htm |archive-date=October 19, 2002}}</ref><ref>{{cite web |url=http://nytm.pastperfectonline.com/archive/67DB8E9F-FD6C-4A8D-8D4E-917305611700 |title=Discontinuance of service Second Avenue elevated line. |date=1942 |website=nytm.pastperfectonline.com |publisher=New York City Board of Transportation |access-date=December 4, 2016 |archive-date=December 20, 2016 |archive-url=https://web.archive.org/web/20161220045354/http://nytm.pastperfectonline.com/archive/67DB8E9F-FD6C-4A8D-8D4E-917305611700 |url-status=live }}</ref><ref name=nyr20170213/> The demolition of the Second Avenue elevated caused overcrowding on the [[BMT Astoria Line|Astoria]] and [[IRT Flushing Line|Flushing Lines]] in Queens, which no longer had direct service to Manhattan's far East Side.<ref name=raskin/>{{rp|208}} The elevated line's closure, as well as a corresponding increase in the East Side's population, increased the need for a Second Avenue subway.<ref name="MESA-August1999">{{cite web |url=https://books.google.com/books?id=SiM3AQAAMAAJ&q=63rd+street |title=Manhattan East Side Transit Alternatives (MESA): Major Investment Study/Draft Environmental Impact Statement, August 1999 |date=August 1999 |publisher=[[Metropolitan Transportation Authority]], [[United States Department of Transportation]], [[Federal Transit Administration]] |access-date=July 11, 2016 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226004401/https://books.google.com/books?id=SiM3AQAAMAAJ&q=63rd+street#v=snippet&q=63rd%20street&f=false |url-status=live }}</ref><ref>{{cite news |url=https://timesmachine.nytimes.com/timesmachine/1940/06/12/113091259.pdf |title=TWO 'EL' LINES END TRANSIT SERVICE; Part of Ninth Ave., First in the World, and Second Ave. Mark Last Runs PASSING IS NOT MOURNED American Woman's Club Holds Wake in Jubilation Over Cessation of Noise |date=June 12, 1940 |work=The New York Times |access-date=August 28, 2017 |language=en-US |issn=0362-4331 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226003453/https://timesmachine.nytimes.com/timesmachine/1940/06/12/113091259.html?pdf_redirect=true&site=false |url-status=live }}</ref>

In 1944, BOT superintendent Philip E. Pheifer put forth a proposal for Second Avenue Subway services, which would branch extensively off to [[B Division (New York City Subway)|B Division]].<ref name="nycsub 1972"/><ref name=raskin/>{{rp|209–210}} The subway was originally to be opened by 1951,<ref name="nymag 20090724"/> but in 1945, plans for the Second Avenue Subway were again revised.<ref name="nycsubway.org"/><ref name=raskin/>{{rp|210–211}} Another plan was put forth in 1947 by Colonel Sidney H. Bingham, a city planner and former [[Interborough Rapid Transit Company]] (IRT) engineer. O'Dwyer and Gross believed that construction of a Second Avenue subway line would be vital to both increasing capacity on existing lines and allowing new branch lines to be built.<ref name="nycsub 1972"/><ref name=raskin/>{{rp|209}} Bingham's proposal involved more branch lines and track connections than did Phiefer's, and similar to the 1960s and 1990s phased proposals, was to be built in sections.<ref name="nycsub 1972"/><ref name=raskin/>{{rp|209}}<ref name="thejoekorner 1947">{{cite web |url=http://www.thejoekorner.com/bdtrans-51/bd-trans-51-plan-indx.html |title=Board of Transportation&nbsp;– 1951 |publisher=Thejoekorner.com |access-date=March 25, 2014 |archive-date=February 24, 2021 |archive-url=https://web.archive.org/web/20210224152538/http://www.thejoekorner.com/bdtrans-51/bd-trans-51-plan-indx.html |url-status=dead }}</ref> In 1948, New York City was short $145&nbsp;million of the $800&nbsp;million program needed for rehabilitation and proposed capital improvements. The City petitioned the New York State Legislature to exceed its $655&nbsp;million [[debt ceiling]] so that the city could spend $500&nbsp;million on subway construction, but this request was denied.<ref name="nycsub 1972"/>

[[File:R11-R34 8013 at Rockaway Park - Beach 116th Street Station.jpg|thumb|right|alt=An R11 car built for the Second Avenue Subway|A [[R11 (New York City Subway car)|R11 car]], ten of which were built for the Second Avenue Subway.<ref name="nyt 20070324"/>]]

The BOT then ordered ten new prototype subway cars made of [[stainless steel]] from the [[Budd Company]]. These R11 cars, so called because of their contract number, were delivered in 1949 and specifically intended for the Second Avenue Subway. They cost US$100,000 (equivalent to ${{format price|{{inflation|US|100e3|1949}}}} in {{Inflation/year|US}}) each; the train became known as the "million dollar train".<ref name="nyt 20070324">{{cite news |last=Neuman |first=William |title=A Museum-Quality Car for a Subway Yet Unbuilt |website=The New York Times |date=March 24, 2007 |url=https://www.nytimes.com/2007/03/24/nyregion/24subway.html |access-date=September 30, 2015 |archive-date=June 5, 2015 |archive-url=https://web.archive.org/web/20150605103035/http://www.nytimes.com/2007/03/24/nyregion/24subway.html |url-status=live }}</ref><ref name="nycsub r11">[http://www.nycsubway.org/perl/caption.pl?/img/cars/sheet013-r11.jpg R-11] {{Webarchive|url=https://web.archive.org/web/20140408213641/http://www.nycsubway.org/perl/caption.pl?/img/cars/sheet013-r11.jpg |date=April 8, 2014 }} Datasheet</ref> The cars featured [[porthole]] style round windows and a new [[public address system]]. Reflecting [[public health]] concerns of the day, especially regarding [[polio]], the R11 cars were equipped with [[electrostatic]] [[air filter]]s and [[ultraviolet]] lamps in their ventilation systems to kill germs.<ref name="nyt 20070324"/><ref name="nycsub r11"/>

In 1949, Queens and Lower Manhattan residents complained that the Second Avenue Subway would not create better transit options for them.<ref name="nycsub 1972"/> In 1950, a revised plan involved connections from Queens.<ref name="nycsub 1972"/><ref name="thejoekorner 1947"/> New York voters approved a [[bond measure]] for its construction in 1951, and the city was barely able to raise the requisite $559 million for the construction effort. However, the onset of the [[Korean War]] caused soaring prices for [[construction materials]] and saw the beginning of massive [[inflation]].<ref name="nycsub 1972"/><ref name="nymag 20090724"/><ref>{{cite news |url=https://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19510914_subway_doc.pdf |title=$500,000,000 VOTED FOR 2D AVE. SUBWAY BY ESTIMATE BOARD |last=Crowell |first=Paul |date=September 14, 1951 |work=The New York Times |access-date=January 2, 2017 |via=The New York Times Archive |archive-date=December 5, 2019 |archive-url=https://web.archive.org/web/20191205040235/http://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19510914_subway_doc.pdf |url-status=live }}</ref> Money from the 1951 bond measure was diverted to buy new cars, lengthen platforms, and maintain other parts of the aging New York City Subway system.<ref name="thejoekorner 1947"/><ref name=":44">{{cite news |url=https://www.nytimes.com/1957/01/17/archives/dwindling-transit-funds-most-of-halfbillion-voted-for-a-2d-ave.html |title=Dwindling Transit Funds; Most of Half-Billion Voted for a 2d Ave. Subway Has Gone Elsewhere The Situation Changes Modernization Is Pushed |last=Levey |first=Stanley |date=January 17, 1957 |newspaper=The New York Times |issn=0362-4331 |access-date=January 3, 2017 |archive-date=January 3, 2017 |archive-url=https://web.archive.org/web/20170103094600/http://www.nytimes.com/1957/01/17/archives/dwindling-transit-funds-most-of-halfbillion-voted-for-a-2d-ave.html |url-status=live }}</ref> Out of a half-billion-dollar bond measure, only $112&nbsp;million (equivalent to ${{format price|{{inflation|US|112e6|1951}}}} in {{Inflation/year|US}}), or 22% of the original amount, went toward the Second Avenue Subway.<ref name="nycsub 1972"/><ref name="nymag 20090724"/><ref name=":44" /> By then, construction was due to start by either 1952 or 1957, with estimated completion by 1958 at the earliest.<ref name="nymag 20090724"/>

The [[Third Avenue Elevated (Manhattan)|Third Avenue Elevated]], the only other elevated line in the area, closed on May 13, 1955,<ref>{{cite news |url=https://timesmachine.nytimes.com/timesmachine/1955/05/13/80773167.pdf |title=Last Train Rumbles On Third Ave. 'El'; An Era Ends With Final Run of Third Avenue 'El' LAST TRAIN ROLLS ON THIRD AVE. 'EL' |last=Katz |first=Ralph |work=The New York Times |date=May 13, 1955 |access-date=December 14, 2016 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226003454/https://timesmachine.nytimes.com/timesmachine/1955/05/13/80773167.html?pdf_redirect=true&site=false |url-status=live }}</ref> and was demolished in 1956.<ref name=":0" /><ref name=nyr20170213/> The Lexington Avenue Line was now the only subway transportation option on the East Side, leading to overcrowding.<ref name="nycsub 1972"/><ref name=nyr20170213/> By 1957, the 1951 bond issue had been almost entirely used for other projects,<ref name=raskin/>{{rp|216}}<ref name=":44" /> and ''The New York Times'' despaired of the line's ever being built.<ref name="nymag 20090724"/> "It certainly will cost more than $500&nbsp;million and will require a new bond issue", wrote one reporter.<ref name=":44" />

=== 1970s construction ===
[[File:Grand Street - Platform.jpg|thumb|alt=Platform of the Grand Street station|The [[Grand Street (IND Sixth Avenue Line)|Grand Street]] station, built as part of the [[Chrystie Street Connection]], was originally conceived with a possible [[cross-platform interchange]] with the Second Avenue Subway.<ref name="raskin"/><ref name="MTA-SASFEISAppB"/>]]

As the early 1960s progressed, the East Side experienced an increase in development, and the Lexington Avenue Line became overcrowded.<ref name="nycsub 1972"/> In 1962, construction began on a connection between the Manhattan and Williamsburg Bridges and the Sixth Avenue Line. This segment, the Chrystie Street Connection, was first proposed in the 1947 plan as the southern end of the Second Avenue line, which would feed into the two bridges. When opened in November 1967, the connection included the new [[Grand Street (IND Sixth Avenue Line)|Grand Street]] station on the Sixth Avenue Line (another station, [[57th Street (IND Sixth Avenue Line)|57th Street]], opened in July 1968), and introduced the most significant service changes ever carried out in the subway's history.<ref name="raskin" />{{rp|216–217}} Grand Street, located under Chrystie Street (the southern end of Second Avenue) was designed to include cross-platform transfers between the Sixth Avenue and Second Avenue Lines.<ref name="raskin"/><ref name="MTA-SASFEISAppB">{{cite web|url=http://web.mta.info/capital/sas_docs/feis/appendixb.pdf#page=26|title=Second Avenue Subway Final Environmental Impact Statement (FEIS): Appendix B: Development of Alternatives|date=May 2004|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|access-date=August 5, 2015|archive-date=November 22, 2016|archive-url=https://web.archive.org/web/20161122065059/http://web.mta.info/capital/sas_docs/feis/appendixb.pdf#page=26|url-status=live}}</ref><ref>{{Cite news|url=https://timesmachine.nytimes.com/timesmachine/1969/07/28/89013185.pdf|title=The Subway Compromise|date=July 28, 1969|newspaper=The New York Times|issn=0362-4331|access-date=December 14, 2016|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226003454/https://timesmachine.nytimes.com/timesmachine/1969/07/28/89013185.html?pdf_redirect=true&site=false|url-status=live}}</ref><ref>[http://images.nycsubway.org/maps/2ave-tr.gif 2nd Avenue Subway&nbsp;– Tentative track plan, Manhattan portion] {{Webarchive|url=https://web.archive.org/web/20120525062419/http://images.nycsubway.org/maps/2ave-tr.gif |date=May 25, 2012 }}, nycsubway.org</ref>

Separately, in 1967, voters approved a ${{Format price|2500000000}} (worth about ${{inflation|US|2,500,000,000|1967|fmt=c|r=-6}} in current dollars) Transportation Bond Issue, which provided over ${{Format price|600000000}} (worth ${{inflation|US|600,000,000|1967|fmt=c|r=-6}} today) for New York City projects, including for a 1968 [[Program for Action]].<ref name=nyr20170213/><ref name="nycsub 1972"/><ref name="int-arch">{{cite web |title=Full text of "Metropolitan transportation, a program for action. Report to Nelson A. Rockefeller, Governor of New York." |website=Internet Archive |date=November 7, 1967 |url=https://archive.org/stream/metropolitantran00newy/metropolitantran00newy_djvu.txt |access-date=February 12, 2016}}</ref> The City secured a $25&nbsp;million [[Urban Mass Transportation Act of 1964|Urban Mass Transportation Act]] (UMTA) grant for initial construction.<ref name="raskin" />{{rp|219}}<ref name="nymag 20090724" /> The Program for Action proposed a Second Avenue line to be built in two phases: a first phase north of 34th Street and a second phase south of there.<ref name=":30">{{Cite news|url=https://www.nytimes.com/1972/09/14/archives/slattery-is-low-in-bid-on-subway-first-section-on-2d-avenue-line.html|title=SLATTERY IS LOW IN BID ON SUBWAY|date=September 14, 1972|newspaper=The New York Times|issn=0362-4331|access-date=December 24, 2016|via=New York Times Archives|archive-date=September 30, 2017|archive-url=https://web.archive.org/web/20170930131035/http://www.nytimes.com/1972/09/14/archives/slattery-is-low-in-bid-on-subway-first-section-on-2d-avenue-line.html|url-status=live}}</ref> The Second Avenue project, for a line from 34th Street to the Bronx, was given top priority.<ref name="nymag 20090724"/><ref name=nyr20170213/> 

The line's planned stops in Manhattan, spaced farther apart than those on existing subway lines, proved controversial.<ref name=":18">{{Cite magazine|url=https://books.google.com/books?id=CuMCAAAAMBAJ&pg=PA36|title=Second Avenue Subway: Bumpy Road Ahead|last=Cohen|first=Richard|date=February 8, 1971|magazine=New York Magazine|publisher=New York Media, LLC|location=New York|pages=36–39|language=en|via=[[Google Books]]|access-date=November 21, 2020|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226004430/https://books.google.com/books?id=CuMCAAAAMBAJ&pg=PA36#v=onepage&q&f=false|url-status=live}}</ref>{{Rp|37}} The Second Avenue line was criticized as a "rich man's express, circumventing the [[Lower East Side]] with its complexes of high-rise low- and middle-income housing and slums in favor of a [[Wikt:silk-stocking#Adjective|silk stocking]] route."<ref name=raskin/>{{rp|218}} In response to protests, the MTA added stations at 72nd Street<ref name=":31">{{Cite news|url=https://timesmachine.nytimes.com/timesmachine/1971/08/28/79404183.pdf|title=M.T.A. Adds a Stop, 72d St., To Its 2d Avenue Subway Plan|last=Prial|first=Frank J.|date=August 28, 1971|work=The New York Times|page=29|access-date=December 21, 2016|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226003457/https://timesmachine.nytimes.com/timesmachine/1971/08/28/79404183.html?pdf_redirect=true&site=false|url-status=live}}</ref> and 96th Street.<ref name="nycsubway.org 1971">{{cite web |url=http://www.nycsubway.org/wiki/Second_Avenue_Subway:_Route_132-A |title=DRAFT ENVIRONMENTAL STATEMENT, SECOND AVENUE SUBWAY, ROUTE 132-A |work=Urban Mass Transportation Administration |publisher=nycsubway.org |date=August 1971 |access-date=February 13, 2016 |archive-date=May 22, 2014 |archive-url=https://web.archive.org/web/20140522213052/http://www.nycsubway.org/wiki/Second_Avenue_Subway:_Route_132-A |url-status=live }}</ref><ref>{{Cite news|url=https://www.nytimes.com/1971/10/04/archives/mta-agrees-to-station-at-96th-st-on-2d-ave-line.html|title=M.T.A. Agrees to Station At 96th St. on 2d Ave. Line|last=Spiegel|first=Irving|date=October 4, 1971|newspaper=The New York Times|issn=0362-4331|access-date=December 21, 2016|archive-date=September 30, 2017|archive-url=https://web.archive.org/web/20170930084911/http://www.nytimes.com/1971/10/04/archives/mta-agrees-to-station-at-96th-st-on-2d-ave-line.html|url-status=live}}</ref> The MTA issued a plan for a spur line, called the "cuphandle", to serve the heart of the Lower East Side. Branching off from the IND Sixth Avenue Line near the Second Avenue station, the spur would run east on Houston Street, turn north on Avenue C, and turn west on 14th Street, connecting to the [[BMT Canarsie Line]].<ref name=":18"/>{{Rp|39}}

A combination of Federal and State funding was obtained for the project. In March 1972, the entire cost of the section between 34th Street and 126th Street, according to the project's Draft Environmental Study, was estimated to be $381&nbsp;million.<ref name=":34">{{Cite book|title=Second Ave subway construction, 34th St to 126th St, Manhattan Draft Environmental Impact Statement.|date=March 1972|publisher=Urban Mass Transportation Administration|hdl = 2027/ien.35556030208045}}</ref>{{Rp|1}} In June 1972, it was announced that UMTA would grant $25&nbsp;million for the construction of this section of the line. The MTA had requested $254&nbsp;million in federal funds for the northern part of the line. Preliminary estimates of the cost of the southern portion of the line came to $450&nbsp;million.<ref>{{Cite news|url=https://www.nytimes.com/1972/06/11/archives/us-agrees-to-aid-2d-avenue-subway-us-to-help-finance-2d-ave-subway.html|title=U.S. Agrees to Aid 2d Avenue Subway|date=June 11, 1972|newspaper=The New York Times|issn=0362-4331|access-date=December 24, 2016|via=New York Times Archive|archive-date=January 8, 2017|archive-url=https://web.archive.org/web/20170108204432/http://www.nytimes.com/1972/06/11/archives/us-agrees-to-aid-2d-avenue-subway-us-to-help-finance-2d-ave-subway.html|url-status=live}}</ref>

Construction on a tunnel segment between 99th and 105th Streets began in October 1972.<ref name=":7">{{cite web|url=http://web.mta.info/capital/sas_docs/feis/appendixb.pdf|title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Appendix B Development of Alternatives|date=May 2004|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 7, 2016|archive-date=November 22, 2016|archive-url=https://web.archive.org/web/20161122065059/http://web.mta.info/capital/sas_docs/feis/appendixb.pdf|url-status=live}}</ref><ref name="mtasas">{{cite web|url=http://web.mta.info/capconstr/sas/background.html|title=Second Avenue Subway|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=April 7, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140408220035/http://web.mta.info/capconstr/sas/background.html|archive-date=April 8, 2014}}</ref><ref name=":25">{{Cite news|url=https://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19721028_subway_doc.pdf|title=Rockefeller and Lindsey Break Ground for 2d Avenue Subway|date=October 28, 1972|work=[[The New York Times]]|access-date=December 21, 2016|via=nytimes.com archive|archive-date=August 29, 2017|archive-url=https://web.archive.org/web/20170829074751/http://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19721028_subway_doc.pdf|url-status=live}}</ref>  A second segment between 110th and 120th Street in [[East Harlem]] started construction in March 1973.<ref name="nyt 19720726" /><ref name=":26">{{cite news |last=Burks |first=Edward C. |title=Beame and Wilson Man the Jackhammers To Start 4th Segment of 2d Ave. Subway; A 1920's Project Some See No Alternative Rush Hour Still Jammed Headache for Neighbors Completion Set for '75 |newspaper=The New York Times |date=July 26, 1974 |url=https://timesmachine.nytimes.com/timesmachine/1974/07/26/79631860.pdf |access-date=October 4, 2015 |page=10 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226005506/https://timesmachine.nytimes.com/timesmachine/1974/07/26/79631860.html?pdf_redirect=true&site=false |url-status=live }}</ref> In October 1973, the line's [[Chinatown, Manhattan|Chinatown]] segment began construction at [[Canal Street (Manhattan)|Canal Street]] under the foot of the Manhattan Bridge between Canal and Division Streets.<ref name="nyt 19720726">{{cite news |last=Burks |first=Edward C. |title=GROUND IS BROKEN FOR 2D AVE. LINK; Downtown Subway Section Begins With Ceremony Led by Lindsay and Ronan Projects Are Listed Interest in French Train |newspaper=The New York Times |date=October 25, 1973 |url=https://timesmachine.nytimes.com/timesmachine/1973/10/25/91018297.pdf |access-date=October 4, 2015 |page=51 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226005501/https://timesmachine.nytimes.com/timesmachine/1973/10/25/91018297.html?pdf_redirect=true&site=false |url-status=live }}</ref> A fourth segment started construction in July 1974, between Second and Ninth Streets in the [[East Village, Manhattan|East Village]].<ref name=":26" /><ref>{{Cite book|url=https://books.google.com/books?id=MyBQAAAAYAAJ&q=February+1974|title=Engineering News-record|date=January 1974|publisher=McGraw-Hill|volume=192|language=en|access-date=November 21, 2020|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226020750/https://books.google.com/books?id=MyBQAAAAYAAJ&q=February+1974|url-status=live}}</ref> In total, construction on the Second Avenue Line during the 1970s spanned over 27 blocks.<ref name=":25" /><ref name="nyt 19720726" /><ref name=":26" />

The city soon experienced [[New York City 1970s fiscal crisis|its most dire fiscal crisis]] yet, due to the stagnant economy of the early 1970s, combined with the [[White flight|massive outflow of city residents to the suburbs]].<ref name="mtasas" /> The system was already in decline. The subway had seen a 40% decrease in ridership since 1947, and a $200&nbsp;million subsidy for the MTA, as well as a 1952 fare increase had not been enough to pay for basic upkeep for the subway system, let alone fund massive expansion projects like the Second Avenue Subway.<ref name=":19">{{Cite magazine|url=https://books.google.com/books?id=WOcCAAAAMBAJ&pg=PA52|title=A Fare Question|last=Kheel|first=Theodore|date=April 23, 1973|magazine=New York Magazine|publisher=New York Media, LLC |pages=52–53|language=en|via=[[Google Books]]|access-date=November 21, 2020|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226010604/https://books.google.com/books?id=WOcCAAAAMBAJ&pg=PA52#v=onepage&q&f=false|url-status=live}}</ref>{{Rp|52}} When plans were finalized in 1971, the subway had been proposed for completion by 1980,<ref name=":18" />{{Rp|38}} but two years later, its completion date was forecast as 2000.<ref name=":19" />{{Rp|52}} In October 1974, the MTA chairman, David Yunich, announced that the completion of the line north of 42nd Street was pushed back to 1983 and the portion to the south in 1988.<ref>{{Cite news|url=https://www.nytimes.com/1974/11/01/archives/2d-ave-subway-delayed-till86-as-costs-spiral-completion-of-other.html|title=2D AVE. SUBWAY DELAYED TILL '86-AS COSTS SPIRAL|last=Burks|first=Edward C.|date=November 1, 1974|newspaper=The New York Times|issn=0362-4331|access-date=December 24, 2016|via=New York Times Archives|archive-date=January 7, 2017|archive-url=https://web.archive.org/web/20170107012540/http://www.nytimes.com/1974/11/01/archives/2d-ave-subway-delayed-till86-as-costs-spiral-completion-of-other.html|url-status=live}}</ref>

In December 1974, New York City mayor [[Abraham Beame]] proposed a six-year transit construction program that would reallocate $5.1&nbsp;billion of funding from the Second Avenue Line to complete new lines in Queens and to modernize the existing infrastructure, which was rapidly deteriorating and in dire need of repair.<ref name=":32">{{cite news|url=https://timesmachine.nytimes.com/timesmachine/1975/01/10/121531917.pdf|title=2d Ave. Tunnelers Push On, Despite Potential Futility; Proposal by Beame|last=Montgomery|first=Paul L.|date=January 10, 1975|newspaper=The New York Times|page=78|via=New York Times Archives|access-date=October 4, 2015|archive-date=February 26, 2024|archive-url=https://web.archive.org/web/20240226005503/https://timesmachine.nytimes.com/timesmachine/1975/01/10/121531917.html?pdf_redirect=true&site=false|url-status=live}}</ref> Beame issued a stop-work order for the line in September 1975,<ref name="nyt 19750926">{{cite news |last=Burks |first=Edward C. |title=WORK IS STOPPED ON SUBWAY LINE; City Lacks Funds to Finish Part of 2d Ave. Project |newspaper=The New York Times |date=September 26, 1975 |url=https://timesmachine.nytimes.com/timesmachine/1975/09/26/80066862.pdf |access-date=October 4, 2015 |page=41 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226005504/https://timesmachine.nytimes.com/timesmachine/1975/09/26/80066862.html?pdf_redirect=true&site=false |url-status=live }}</ref> whereupon construction of the section between Second and Ninth Streets was halted, and no other funding was allocated to the line's construction.<ref name="nyt 19750926" /> Besides the Chrystie Street Connection, only three sections of tunnel had been completed. These tunnels were sealed.<ref name="nymag 20090724" />

In 1978, when the New York City Subway was at its lowest point in its existence, State Comptroller [[Arthur Levitt]] stated that there were no plans to finish the line.<ref name="nymag 20090724" /> During the 1980s, plans for the Second Avenue line stagnated. Construction on the 63rd Street Lines continued. The IND portion of the line opened in 1989 and extended to [[21st Street–Queensbridge (IND 63rd Street Line)|21st Street–Queensbridge]] in [[Long Island City]], [[Queens]], but it did not include a connection to the Second Avenue line.<ref name=":20" /> Of this failure to complete construction, [[Gene Russianoff]], an advocate for subway riders since 1981, stated: "It's the most famous thing that's never been built in New York City, so everyone is skeptical and rightly so. It's much-promised and never delivered."<ref name=":20">{{cite news |url=https://www.nytimes.com/2005/11/14/nyregion/14mta.html |title=The Bond Passed. Now Comes the Hard Part: Actually Building a 2nd Avenue Subway |last=Chan |first=Sewell |author-link=Sewell Chan |date=November 14, 2005 |newspaper=The New York Times |access-date=April 7, 2014 |archive-date=April 11, 2009 |archive-url=https://web.archive.org/web/20090411094354/http://www.nytimes.com/2005/11/14/nyregion/14mta.html |url-status=live }}</ref>

===1990s plans===
[[File:SAS 9383 (17323112833).jpg|thumb|The track junction with the BMT 63rd Street Line south of 72nd Street]]

With the city's economic and budgetary recovery in the 1990s, there was a revival of efforts to complete construction of the SAS. Rising ridership on the [[IRT Lexington Avenue Line]], the only subway trunk line east of [[Central Park]], demonstrated the need for the Second Avenue Line, as capacity and safety concerns rose.<ref name="mta20110922" /> The four-track IRT Lexington Avenue Line, the lone [[rapid transit]] option in the [[Upper East Side]] and [[East Harlem]] since the 1955 closure of the Third Avenue elevated, is the most crowded subway line in the country.<ref name="mta20110922" /> The line saw an average of 1.3 million daily riders in 2015.<ref name="mta20110922" /><ref name=":9">{{Cite news|url=http://www.amny.com/transit/second-avenue-subway-to-open-new-year-s-day-cuomo-says-1.12776549|title=Cuomo: Second Ave. subway to open New Year's Day|newspaper=am New York|access-date=December 20, 2016|date=December 19, 2016|archive-date=December 19, 2016|archive-url=https://web.archive.org/web/20161219224937/http://www.amny.com/transit/second-avenue-subway-to-open-new-year-s-day-cuomo-says-1.12776549|url-status=live}}</ref> This is more than the daily ridership of the second-busiest subway system in the U.S., the [[Washington Metro]], as well as more than the combined daily riderships of [[Bay Area Rapid Transit|San Francisco's]] and [[Massachusetts Bay Transportation Authority|Boston's]] transit systems.<ref name="mta20110922">{{cite web|url=http://web.mta.info/capconstr/sas/feis.htm |title=Second Avenue Subway in the Borough of Manhattan, New York County, New York Final Environmental Impact Statement And Final Section 4(f) and Section 6(f) Evaluation |date=April 2004 |pages=1–5, 1–6 |format=PDF |access-date=September 22, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20140408220803/http://web.mta.info/capconstr/sas/feis.htm |archive-date=April 8, 2014 }}</ref> Local [[bus route]]s are just as crowded during various times of the day, with the parallel [[list of bus routes in Manhattan#M15|M15]] local and [[Select Bus Service#M15|M15 Select Bus Service]] routes seeing 46,000 passengers per weekday in 2016, translating to 14.5 million passengers that year.<ref>{{cite web|url=http://web.mta.info/nyct/facts/ridership/ridership_bus_annual.htm|title=Annual Bus Ridership|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=December 14, 2016|archive-date=September 24, 2017|archive-url=https://web.archive.org/web/20170924045929/http://web.mta.info/nyct/facts/ridership/ridership_bus_annual.htm|url-status=live}}</ref><ref>{{cite web|url=http://web.mta.info/nyct/facts/ridership/ridership_bus.htm|title=Average Weekday Bus Ridership|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=December 14, 2016|archive-date=July 7, 2013|archive-url=https://web.archive.org/web/20130707044411/http://web.mta.info/nyct/facts/ridership/ridership_bus.htm|url-status=live}}</ref>

In 1991, then-New York Governor [[Mario Cuomo]] allocated $22&nbsp;million to renew planning and design efforts for the Second Avenue line,<ref>{{cite web | last=Finder | first=Alan | title=Cuomo Ideas for New York City: Some Are Old, Some Are New | website=The New York Times | date=September 25, 1991 | url=https://www.nytimes.com/1991/09/25/nyregion/cuomo-ideas-for-new-york-city-some-are-old-some-are-new.html | access-date=April 9, 2018 | archive-date=April 10, 2018 | archive-url=https://web.archive.org/web/20180410071851/https://www.nytimes.com/1991/09/25/nyregion/cuomo-ideas-for-new-york-city-some-are-old-some-are-new.html | url-status=live }}</ref> but two years later, the MTA, facing budget cuts, removed these funds from its capital budget.<ref>{{cite web | last=Wald | first=Matthew L. | title=Next Mayor Faces Expensive Challenges on Basic Services and Repairs | website=The New York Times | date=October 28, 1993 | url=https://www.nytimes.com/1993/10/28/nyregion/next-mayor-faces-expensive-challenges-on-basic-services-and-repairs.html | access-date=April 9, 2018 | archive-date=April 9, 2018 | archive-url=https://web.archive.org/web/20180409233744/https://www.nytimes.com/1993/10/28/nyregion/next-mayor-faces-expensive-challenges-on-basic-services-and-repairs.html | url-status=live }}</ref> In 1995, the MTA began its Manhattan East Side Alternatives (MESA) study, both a MIS and a DEIS, seeking ways to alleviate overcrowding on the Lexington Avenue Line and improve mobility on Manhattan's East Side.<ref name=":7" /><ref name="MESA">{{cite web|url=http://web.mta.info/capital/sas_docs/final_summary_report.pdf|title=Manhattan East Side Transit Alternatives (MESA)/Second Avenue Subway Summary Report|date=October 11, 2001|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 9, 2016|archive-date=November 7, 2016|archive-url=https://web.archive.org/web/20161107143807/http://web.mta.info/capital/sas_docs/final_summary_report.pdf|url-status=live}}</ref>{{rp|7–8}} Second Avenue was chosen over First Avenue for logistical reasons.<ref name=":7" /> The MTA started the Lower Manhattan Access Study (LMA) in November 1997. The construction of the Second Avenue Subway from 63rd Street to Lower Manhattan was one of the five building alternatives developed by the study.<ref name="MESA" />{{rp|6, 7}} A 1999 DEIS only proposed new subway service on Second Avenue from 63rd to 125th Street, as well as swapping the local and express services on the Broadway Line.<ref name="AppendixB">{{cite web|url=http://web.mta.info/capital/sas_docs/sdeis/appendixb.pdf|title=Second Avenue Subway Supplemental Draft Environmental Impact Statement (SDEIS), April 2003 Appendix B Development of Alternatives|date=April 2003|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 9, 2016|archive-date=July 11, 2019|archive-url=https://web.archive.org/web/20190711223541/http://web.mta.info/capital/sas_docs/sdeis/appendixb.pdf|url-status=live}}</ref>{{rp|20–21}} A spur to [[Grand Central Terminal]] was considered, but later dropped.<ref name="MESA" />{{rp|17}}

Due in part to strong public support, the MTA Board committed in April 2000 to building a full-length subway line along the East Side, from East Harlem to Lower Manhattan.<ref>{{cite web | last=Newman | first=Andy | title=New Subway Line in Transit Budget | website=The New York Times | date=April 20, 2000 | url=https://www.nytimes.com/2000/04/20/nyregion/new-subway-line-in-transit-budget.html | access-date=April 9, 2018 | archive-date=April 9, 2018 | archive-url=https://web.archive.org/web/20180409233642/https://www.nytimes.com/2000/04/20/nyregion/new-subway-line-in-transit-budget.html | url-status=live }}</ref><ref name="MESA" />{{rp|18}} In May 2000, the MTA Capital Program Review Board approved the MTA's 2000–2004 Capital Program, which allocated $1.05&nbsp;billion for the construction of the Second Avenue Subway.<ref>{{cite web | title=METRO NEWS BRIEFS: NEW YORK; M.T.A.'s Capital Plan Wins Final Approval | website=The New York Times | date=May 5, 2000 | url=https://www.nytimes.com/2000/05/05/nyregion/metro-news-briefs-new-york-mta-s-capital-plan-wins-final-approval.html | access-date=April 9, 2018 | archive-date=April 10, 2018 | archive-url=https://web.archive.org/web/20180410002253/https://www.nytimes.com/2000/05/05/nyregion/metro-news-briefs-new-york-mta-s-capital-plan-wins-final-approval.html | url-status=live }}</ref><ref name="MESA" />{{rp|18}} The next year, a contract for subway design was awarded to DMJM Harris/[[Arup Group Limited|Arup]] Joint Venture.<ref name="nymag 20090724" /> A new draft statement proposed the full-length line from 125th to 14th Streets; in Lower Manhattan; it was decided to build the line under Water Street.<ref name="AppendixB" />{{rp|26–27}}<ref name=":16">{{cite web|url=http://web.mta.info/capital/sas_docs/sas_noi.pdf|title=Supplemental Draft Environmental Impact Statement on the Manhattan East Site Alternatives Project— ''Second Avenue Subway.'' AGENCY: Federal Transit Administration, DOT. ACTION: Notice of intent to prepare a supplemental draft environmental impact statement.|date=March 22, 2001|website=mta.info|publisher=Federal Transit Administration|access-date=August 9, 2016|page=2|archive-date=November 7, 2016|archive-url=https://web.archive.org/web/20161107145002/http://web.mta.info/capital/sas_docs/sas_noi.pdf|url-status=live}}</ref>

In December 2001, the [[Federal Transit Administration]] approved the start of preliminary engineering on a full-length Second Avenue Subway.<ref name=":7" /> The MTA's final [[environmental impact statement]] (FEIS) was approved in April 2004. This latest proposal is for a two-track line from 125th Street and Lexington Avenue in Harlem, down Second Avenue to [[Hanover Square (New York City)|Hanover Square]] in the [[Financial District, Manhattan|Financial District]].<ref name="MTA 2007">{{cite web|url=http://www.mta.info/press-release/mta-headquarters/second-avenue-subway-history|title=Second Avenue Subway History|date=April 12, 2007|website=mta.info|publisher=Metropolitan Transportation Authority|archive-url=https://web.archive.org/web/20151221130935/http://www.mta.info/press-release/mta-headquarters/second-avenue-subway-history|archive-date=December 21, 2015|url-status=dead|access-date=March 31, 2016|quote=In April 2004, the Second Avenue Subway Final Environmental Impact Statement (FEIS) was published.}}</ref> The final plan called for the full-length Second Avenue line to carry two services: the [[T (New York City Subway service)|T]], with a route emblem colored {{NYCS const|color|T}},<ref name="nyt20110822"/> as well as a rerouted [[Q (New York City Subway service)|Q]] train. Phase 1 rerouted the Q, the [[BMT Broadway Line|Broadway Express]] via the BMT 63rd Street Line and north along Second Avenue, to the Upper East Side at [[96th Street (Manhattan)|96th Street]]. Phase 2 will extend the rerouted Q train to [[125th Street (Manhattan)|125th Street]] and Lexington Avenue. In Phase Three, the new T train will run from 125th Street to [[Houston Street (Manhattan)|Houston Street]]. The final phase will extend T train service from Houston Street to [[Hanover Square, Manhattan|Hanover Square]] in Lower Manhattan.<ref name=":7" /><ref>{{cite web|url=http://web.mta.info/capital/sas_alt.html|title=MTA Capital Construction – Second Avenue Subway Project Description|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=October 5, 2013|url-status=dead|archive-url=https://web.archive.org/web/20140408214933/http://web.mta.info/capconstr/sas/description.html|archive-date=April 8, 2014}}</ref>

The {{convert|1.8|mi|km|adj=on}}<ref name=":13" /> first phase was built within budget, at $4.45&nbsp;billion.<ref name=":13">*{{cite web|url=http://www.rew-online.com/2014/05/14/light-at-end-of-tunnel-for-second-ave-subway/|title=Real Estate Weekly » Blog Archive » Light at end of tunnel for Second Ave. subway|last=Putzier|first=Konrad|date=May 14, 2014|publisher=Rew-online.com|access-date=June 5, 2014|archive-url=https://web.archive.org/web/20170907034400/http://rew-online.com/2014/05/14/light-at-end-of-tunnel-for-second-ave-subway/|archive-date=September 7, 2017|url-status=dead}}
* {{cite web|url=http://www.masstransitmag.com/article/12227191/project-update-second-avenue-subway|title=Project Update: Second Avenue Subway|date=August 15, 2016|website=Mass Transit|access-date=October 27, 2016|archive-date=March 27, 2019|archive-url=https://web.archive.org/web/20190327123026/https://www.masstransitmag.com/rail/article/12227191/project-update-second-avenue-subway|url-status=live}}</ref><ref name="CBS News 20152">{{cite web|url=http://www.cbsnews.com/news/drones-exclusive-look-at-new-york-city-second-avenue-subway-line/|title=Drone takes tour of NYC's 2nd Avenue subway line|date=September 16, 2015|website=CBS News|access-date=October 27, 2016|archive-date=October 24, 2016|archive-url=https://web.archive.org/web/20161024105935/http://www.cbsnews.com/news/drones-exclusive-look-at-new-york-city-second-avenue-subway-line/|url-status=live}}</ref> Its construction site was designated as being from 105th Street and Second Avenue to 63rd Street and Third Avenue.<ref name="newyork20140130">{{cite web|url=http://www.newyork.com/articles/real-estate/updates-on-nycs-biggest-subway-projects-second-avenue-and-east-side-access-59421/|title=Updates on NYC's Biggest Subway Projects: Second Avenue and East Side Access|last=Nonko|first=Emily|date=January 30, 2014|publisher=NewYork.com|access-date=June 5, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140517132213/http://www.newyork.com/articles/real-estate/updates-on-nycs-biggest-subway-projects-second-avenue-and-east-side-access-59421/|archive-date=May 17, 2014}}</ref> [[Deep bore tunneling]] methods were to be used in order to avoid the disruptions for road traffic, pedestrians, utilities and local businesses produced by [[cut-and-cover]] methods of past generations. Stations were to retain cut-and-cover construction.<ref>{{cite web|url=http://construction.com/NewsCenter/Headlines/RP/20060523ny.asp|title=New York's Subway System Finally Starting Major Expansion|date=May 2006|publisher=newyork.construction.com|author=Stabile, Tom|access-date=December 12, 2008|archive-url=https://web.archive.org/web/20080509014513/http://construction.com/NewsCenter/Headlines/RP/20060523ny.asp|archive-date=May 9, 2008}}</ref> The total cost of the {{convert|8.5|mi|km|adj=on}} line is expected to exceed $17&nbsp;billion.<ref name="nymag-Sargent segments">{{cite journal|last=Sargent|first=Greg|date=March 29, 2004|title=The Line That Time Forgot&nbsp;– Second Avenue Subway|url=http://nymag.com/nymetro/news/features/n_10109/|journal=New York Magazine|access-date=August 2, 2009|archive-date=May 6, 2009|archive-url=https://web.archive.org/web/20090506050501/http://nymag.com/nymetro/news/features/n_10109/|url-status=live}}</ref> In 2014, [[MTA Capital Construction]] President Dr. Michael Horodniceanu stated that the whole line may be completed as early as 2029,<ref>{{cite news |url=http://www.nydailynews.com/new-york/ave-subway-line-construction-progressing-officials-article-1.1795916 |title=Second Avenue subway line construction is progressing: officials |newspaper=[[Daily News (New York)|New York Daily News]] |date=May 16, 2014 |access-date=May 19, 2014 |author=Nolan, Caitlin |archive-date=January 3, 2017 |archive-url=https://web.archive.org/web/20170103104938/http://www.nydailynews.com/new-york/ave-subway-line-construction-progressing-officials-article-1.1795916 |url-status=live }}</ref> and would serve 560,000 daily passengers upon completion.<ref>{{cite news |last=Smith |first=Stephen J. |url=http://nextcity.org/daily/entry/the-next-20-years-for-new-yorks-mta |title=The Next 20 Years for New York's MTA&nbsp;– Next City |publisher=Nextcity.org |date=October 2, 2013 |access-date=June 5, 2014 |archive-date=May 14, 2014 |archive-url=https://web.archive.org/web/20140514182746/http://nextcity.org/daily/entry/the-next-20-years-for-new-yorks-mta |url-status=live }}</ref> As of December 2016, only Phases 1 and 2 would be completed by 2029.<ref name="fta20161227">{{Cite news|url=https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/New_York_City_2nd_Ave_Subway_Phase_2_Profile.pdf|title=New York City 2nd Ave Subway Phase 2 Profile|date=December 27, 2016|newspaper=FTA|access-date=January 4, 2017|url-status=dead|archive-url=https://web.archive.org/web/20170105000123/https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/New_York_City_2nd_Ave_Subway_Phase_2_Profile.pdf|archive-date=January 5, 2017}}</ref> The line is described as the New York City Subway's "first major expansion" in more than a half-century.<ref name="The Second Avenue subway explained">{{Cite news|url=http://www.amny.com/transit/the-second-avenue-subway-explained-1.11244882|title=The Second Avenue subway explained|newspaper=am New York|access-date=October 27, 2016|archive-date=October 27, 2016|archive-url=https://web.archive.org/web/20161027123735/http://www.amny.com/transit/the-second-avenue-subway-explained-1.11244882|url-status=live}}</ref><ref name=":2">{{Cite news|url=https://www.nytimes.com/2016/12/19/nyregion/second-avenue-subway-opening.html|title=2nd Avenue Subway Will Open on New Year's Day, M.T.A. Says|last=Fitzsimmons|first=Emma G.|date=December 19, 2016|newspaper=The New York Times|issn=0362-4331|access-date=December 19, 2016|archive-date=December 19, 2016|archive-url=https://web.archive.org/web/20161219210356/http://www.nytimes.com/2016/12/19/nyregion/second-avenue-subway-opening.html|url-status=live}}</ref> It would add two tracks to fill the gap that has existed since the elevated Second and Third Avenue Lines were demolished in the 1950s.<ref name="mta20110922" /> According to the line's [[Environmental impact statement|final environmental impact statement]], the catchment area of the line's first phase would include 200,000 daily riders.<ref name=":9" /><ref name=":10">*{{cite web|url=http://newyork.cbslocal.com/2014/05/01/cbs-2-exclusive-progress-moves-ahead-for-phase-one-of-second-avenue-subway/|title=Progress Moves Ahead For Phase One Of Second Avenue Subway « CBS New York|date=May 1, 2014|publisher=CBS Local Media, a division of CBS Radio Inc|first=Andrea|last=Gryme|access-date=May 4, 2014|archive-date=May 9, 2014|archive-url=https://web.archive.org/web/20140509004501/http://newyork.cbslocal.com/2014/05/01/cbs-2-exclusive-progress-moves-ahead-for-phase-one-of-second-avenue-subway/|url-status=live}}
* {{cite news|url=http://www.metro.us/newyork/news/local/2014/05/01/10-facts-second-avenue-subway/|title=10 facts about the Second Avenue Subway|last=Sanders|first=Anna|date=May 1, 2014|work=Metro.us|access-date=May 4, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140502213931/http://www.metro.us/newyork/news/local/2014/05/01/10-facts-second-avenue-subway/|archive-date=May 2, 2014}}</ref><ref name=":22">{{cite web|url=https://gizmodo.com/a-subterranean-stroll-through-nycs-newest-train-tunnel-1570826409|title=A Subterranean Stroll Through NYC's Newest Train Tunnel|date=May 2, 2014|publisher=Gizmodo.com|first=Michael|last=Hession|access-date=May 4, 2014|archive-date=May 3, 2014|archive-url=https://web.archive.org/web/20140503150430/http://gizmodo.com/a-subterranean-stroll-through-nycs-newest-train-tunnel-1570826409|url-status=live}}</ref><ref name="amny-20140501">{{cite web|url=http://www.amny.com/transit/second-avenue-subway-progress-dec-2016-end-date-on-track-1.7892110|title=Second Avenue Subway progress: Dec. 2016 end date on track|last=Rivoli|first=Dan|date=May 1, 2014|work=AM New York|access-date=May 14, 2014|archive-date=July 30, 2017|archive-url=https://web.archive.org/web/20170730070058/http://www.amny.com/transit/second-avenue-subway-progress-dec-2016-end-date-on-track-1.7892110|url-status=live}}</ref>

==={{anchor|Phase 1}}Phase 1 construction===
New York voters passed a transportation bond issue in November 2005, allowing for dedicated funding allocated for that phase. Its passage had been seen as critical to its construction, but the bond was passed only by a narrow margin, with 55% of voters approving and 45% disapproving.<ref>{{cite news |last=Chan |first=Sewell |author-link=Sewell Chan |url=https://www.nytimes.com/2005/11/09/nyregion/metrocampaigns/09transport.html |title=Voters Approve Transit Bonds for $2.9 Billion |newspaper=[[The New York Times]] |date=November 9, 2005 |access-date=September 20, 2007 |archive-date=December 10, 2008 |archive-url=https://web.archive.org/web/20081210023259/http://www.nytimes.com/2005/11/09/nyregion/metrocampaigns/09transport.html |url-status=live }}</ref> At the time, the MTA said that the project would be done in 2012<ref name=":27" /> in case the city's [[New York City bid for the 2012 Summer Olympics|2012 Summer Olympics bid]] succeeded, which it had not.<ref name="nymag 20090724" /><ref name=":27">{{cite news|url=https://query.nytimes.com/gst/fullpage.html?res=9C04E2DF103EF937A25752C1A9639C8B63&sec=&spon=&pagewanted=print|title=The Bond Passed. Now Comes the Hard Part: Actually Building a 2nd Avenue Subway.|last=Chan|first=Sewell|date=November 14, 2005|newspaper=The New York Times|access-date=July 29, 2016|archive-date=August 19, 2016|archive-url=https://web.archive.org/web/20160819084107/http://query.nytimes.com/gst/fullpage.html?res=9C04E2DF103EF937A25752C1A9639C8B63&sec=&spon=&pagewanted=print|url-status=live}}</ref> In December 2006, the [[United States Department of Transportation]] (USDOT) announced that they would allow the MTA to commit up to $693&nbsp;million in funds to begin construction of the Second Avenue Subway and that the federal share of such costs would be reimbursed with FTA transit funds, subject to appropriations and final labor certification.<ref>{{cite web |url=http://www.dot.gov/affairs/dot11706.htm |archive-url=https://web.archive.org/web/20090709091123/http://www.dot.gov/affairs/dot11706.htm |title=U.S. Transportation Secretary Signs Record $2.6 Billion Agreement to Fund New Tunnel Network To Give Long Island Commuters Direct Access to Grand Central Station |publisher=[[United States Department of Transportation]] |date=December 18, 2006 |access-date=September 20, 2007 |archive-date=July 9, 2009}}</ref> The USDOT also later gave $1.3&nbsp;billion in [[federal funding]] for the project's first phase, to be funded over a seven-year period.<ref>{{cite news |last=Neuman |first=William |url=https://www.nytimes.com/2007/11/19/nyregion/19subway.html |title=U.S. Approves $1.3 Billion for 2nd Avenue Subway |newspaper=[[The New York Times]] |date=November 19, 2007 |access-date=November 19, 2007 |archive-date=March 20, 2012 |archive-url=https://web.archive.org/web/20120320195051/http://www.nytimes.com/2007/11/19/nyregion/19subway.html |url-status=live }}</ref> Preliminary engineering and a final tunnel design was completed by a [[joint venture]] between [[AECOM]] and [[Arup Group Limited|Arup]].<ref name="arema1">{{cite web|url=http://www.arema.org/eseries/scriptcontent/custom/e_arema/library/2008_Conference_Proceedings/Second_Avenue_Subway-A_Status_Report_2008.pdf |title=Second Avenue Subway: A Status Report |access-date=August 2, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110721194135/http://www.arema.org/eseries/scriptcontent/custom/e_arema/library/2008_Conference_Proceedings/Second_Avenue_Subway-A_Status_Report_2008.pdf |archive-date=July 21, 2011 }}</ref><ref>{{cite web | last=Stabile | first=Tom | title=Second Ave. Subway Sets Next-Century Standards | website=ENR | date=September 19, 2017 | url=https://www.enr.com/articles/42752-second-ave-subway-sets-next-century-standards | access-date=December 1, 2017 | archive-date=August 9, 2020 | archive-url=https://web.archive.org/web/20200809205135/https://www.enr.com/articles/42752-second-ave-subway-sets-next-century-standards | url-status=live }}</ref>

[[File:Second Avenue Subway- March 15, 2014 (13266516025).jpg|thumb|The ceiling of the 86th Street station in December 2013]]

In March 2007, upon completion of preliminary engineering, the MTA awarded a contract for constructing the tunnels, a launch box for the [[tunnel boring machine]] (TBM), and access shafts to S3, a joint venture of Schiavone Construction, [[Skanska]] USA Civil, and J.F. Shea Construction.<ref>{{cite web|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|access-date=December 18, 2016|date=March 20, 2007|url=http://www.mta.info/press-release/mta-headquarters/first-construction-contract-signed-second-avenue-subway|title=First Construction Contract Signed for Second Avenue Subway; Work to Begin in April|url-status=dead|archive-url=https://web.archive.org/web/20140426201719/http://www.mta.info/press-release/mta-headquarters/first-construction-contract-signed-second-avenue-subway|archive-date=April 26, 2014}}</ref><ref>{{cite news |title=MTA Signs Second Ave. Subway Contract |url=http://www.nysun.com/new-york/mta-signs-second-ave-subway-contract/50892/ |newspaper=New York Sun |date=March 21, 2007 |access-date=February 20, 2010 |archive-date=December 5, 2008 |archive-url=https://web.archive.org/web/20081205023113/http://www.nysun.com/new-york/mta-signs-second-ave-subway-contract/50892/ |url-status=dead }}</ref><ref>{{cite web |url=http://www.wnyc.org/news/articles/75760 |title=2nd Avenue Subway Contract Signed |url-status=live |archive-url=https://web.archive.org/web/20070325112634/http://www.wnyc.org/news/articles/75760 |archive-date=March 25, 2007 |website=WNYC |date=March 21, 2007}}</ref> A ceremonial groundbreaking took place on April 12, 2007, at the 99th Street tunnel segment built in the 1970s.<ref>{{Cite news|url=https://www.nytimes.com/2007/04/13/nyregion/13tunnel.html|title=Was There a Ghost? No, Just a Tunnel at the Latest Subway Groundbreaking|last=Neuman|first=William|date=April 13, 2007|work=The New York Times|access-date=June 12, 2017|language=en-US|issn=0362-4331|archive-date=August 16, 2017|archive-url=https://web.archive.org/web/20170816013132/http://www.nytimes.com/2007/04/13/nyregion/13tunnel.html|url-status=live}}</ref> Actual construction work began on April 23, 2007.<ref>{{cite web|url=http://web.mta.info/capconstr/sas/background.html|title=MTA Capital Construction&nbsp;– Second Avenue Subway: History|website=mta.info|publisher=Metropolitan Transportation Authority|archive-url=https://web.archive.org/web/20140408220035/http://web.mta.info/capconstr/sas/background.html|archive-date=April 8, 2014|url-status=dead}}</ref> At the time, it was announced that passengers would be able to ride trains on the new line by the end of 2013.<ref>{{cite press release |title=Second Avenue Subway Breaks Ground |publisher=Metropolitan Transportation Authority |date=April 12, 2007 |url=http://www.mta.info/press-release/mta-headquarters/second-avenue-subway-breaks-ground |access-date=December 24, 2015 |archive-date=December 21, 2015 |archive-url=https://web.archive.org/web/20151221130833/http://www.mta.info/press-release/mta-headquarters/second-avenue-subway-breaks-ground |url-status=dead }}</ref>  Due to cost increases, several features of the subway were cut back soon after construction started: for instance, the 72nd Street station was downsized.<ref name="CB8" /> The MTA also postponed its completion date several times to 2016.<ref>{{cite news|url=https://www.nydailynews.com/new-york/ave-subway-set-back-article-1.360013|title=Second Ave. subway set back&nbsp;– again|last=Donohue|first=Pete|date=April 24, 2009|work=New York Daily News|access-date=August 20, 2021|archive-date=January 31, 2022|archive-url=https://web.archive.org/web/20220131063816/https://www.nydailynews.com/new-york/ave-subway-set-back-article-1.360013|url-status=live}}</ref>

In 2009, contracts were awarded for the [[96th Street (Second Avenue Subway)|96th Street]] [[station box]],<ref>{{cite web|url=http://www.apta.com/mc/rail/previous/2013/program/Documents/GoodrichW_MTA-new-yorks-second-ave.pdf|title="SECOND AVENUE SUBWAY PROJECT" Managing Construction and its Challenges in One of the Country's Densest Urban Environments|date=2013|website=apta.com|publisher=American Public Transportation Association|access-date=December 23, 2016|archive-date=December 20, 2016|archive-url=https://web.archive.org/web/20161220221630/http://www.apta.com/mc/rail/previous/2013/program/Documents/GoodrichW_MTA-new-yorks-second-ave.pdf|url-status=dead}}</ref> as well as for excavation around the 86th Street stations.<ref>{{cite web|url=http://www.apta.com/mc/rail/previous/2013/program/Documents/GoodrichW_MTA-new-yorks-second-ave.pdf|title=SECOND AVENUE SUBWAY PROJECT|date=2013|publisher=2013 Rail Conference|website=apta.com|last=Goodrich|first=William|access-date=December 16, 2016|archive-date=December 20, 2016|archive-url=https://web.archive.org/web/20161220221630/http://www.apta.com/mc/rail/previous/2013/program/Documents/GoodrichW_MTA-new-yorks-second-ave.pdf|url-status=dead}}</ref> The TBM began boring the western tunnel southward from 96th Street in 2010.<ref name="NBC-2010-05-14"/><ref>{{cite press release |title=MTA Launches Second Avenue Subway Tunnel Boring Machine |url=http://www.mta.info/press-release/mta-headquarters/mta-launches-second-avenue-subway-tunnel-boring-machine |access-date=October 5, 2013 |publisher=Metropolitan Transportation Authority |date=May 14, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20131006223833/http://www.mta.info/press-release/mta-headquarters/mta-launches-second-avenue-subway-tunnel-boring-machine |archive-date=October 6, 2013 }}</ref><ref>{{cite web |url=http://www.ny1.com:80/ny1/content/index.jsp?stid=8&aid=66187 |title=Exclusive: Ground Breaking For 2nd Avenue Subway Line Weeks Away |url-status=dead |archive-url=https://web.archive.org/web/20071011130816/http://www.ny1.com/ny1/content/index.jsp?stid=8&aid=66187 |archive-date=October 11, 2007 |website=NY1 |date=January 24, 2007 |last=Cuza |first=Bobby}}</ref> Contracts for tunnels to the [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street station]], and for the excavation of the 72nd Street station, were awarded in 2010.<ref>{{cite book |last1=Davidson |first1=G. |last2=Howard |first2=A. |last3=Jacobs |first3=L. |last4=Pintabona |first4=R. |last5=Zernich |first5=B. |title=North American Tunneling: 2014 Proceedings |publisher=Society for Mining Metallurgy |year=2014 |isbn=978-0-87335-400-4 |url=https://books.google.com/books?id=v96xAwAAQBAJ&pg=PA301 |access-date=November 15, 2015 |page=301}}</ref>{{rp|301}} The following year, contracts were awarded for excavation of the cavern at the 86th Street station,<ref>{{cite web |title=COMMUNITY BOARD EIGHT PROJECT UPDATE |url=http://web.mta.info/capital/sas_pdf/2011_Sept%2026_Final.pdf |publisher=Metropolitan Transportation Authority |access-date=November 15, 2015 |date=September 26, 2011 |archive-date=November 17, 2015 |archive-url=https://web.archive.org/web/20151117015758/http://web.mta.info/capital/sas_pdf/2011_Sept%2026_Final.pdf |url-status=live }}</ref> as well as construction for the Lexington Avenue–63rd Street station.<ref>{{cite web |url=http://web.mta.info/capconstr/procurement/cc_recentawards.htm |title=MTA Capital Construction&nbsp;– Procurement |publisher=Metropolitan Transportation Authority |access-date=April 7, 2014 |archive-date=August 27, 2017 |archive-url=https://web.archive.org/web/20170827234406/http://web.mta.info/capconstr/procurement/cc_recentawards.htm |url-status=live }}</ref><ref>{{cite web|work=Engineering News |url=https://enr.construction.com/engineering/subscription/LoginSubscribe.aspx?cid=16904 |title=Freeze Ground, Thaw Hearts |date=February 2, 2011 |access-date=August 15, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150914185324/https://enr.construction.com/engineering/subscription/LoginSubscribe.aspx?cid=16904 |archive-date=September 14, 2015 }}</ref>

The TBM, digging at a rate of approximately {{convert|50|ft|m}} per day, finished its run at the planned endpoint under 65th Street on February 5, 2011,<ref>{{cite web|url=http://web.mta.info/capital/sas_docs/2011_Feb%2015_Final.pdf|title=COMMUNITY BOARD EIGHT PROJECT UPDATE|publisher=MTA Capital Construction|date=February 15, 2011|access-date=October 16, 2017|archive-date=March 3, 2016|archive-url=https://web.archive.org/web/20160303233749/http://web.mta.info/capital/sas_docs/2011_Feb%2015_Final.pdf|url-status=live}}</ref> and started digging the eastern tunnel.<ref name="NBC-2010-05-14">{{cite news |title=2nd Ave. Subway Tunnel Dig Begins |first=Andrew |last=Siff |url=http://www.nbcnewyork.com/news/local-beat/2nd-Ave-Subway-Tunnel-Dig-Begins-93787364.html |publisher=[[WNBC]] |date=May 14, 2010 |access-date=May 14, 2010 |archive-date=August 5, 2023 |archive-url=https://web.archive.org/web/20230805203830/https://www.nbcnewyork.com/news/local/2nd-ave-subway-tunnel-dig-begins/1886405/ |url-status=live }}</ref> On March 28, 2011, S3, having completed its task of completing the {{convert|7200|ft|m|adj=on}} west tunnel to 65th Street, began drilling the east tunnel to the [[Bellmouth (railroad terminology)|bellmouth]] at the existing [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street]] station. The portion of the west tunnel remaining to be created was then mined using conventional drill-and-blast methods.<ref name=":3">{{cite news|url=http://www.mta.info/news/2011/03/28/tunneling-second-avenue-subway-continues|title=Tunneling for Second Avenue Subway Continues|date=March 28, 2011|work=Metropolitan Transportation Authority|access-date=September 24, 2011|archive-date=August 18, 2014|archive-url=https://web.archive.org/web/20140818144011/http://www.mta.info/news/2011/03/28/tunneling-second-avenue-subway-continues|url-status=dead}}</ref> In September 2011, the TBM completed its run to the Lexington Avenue–63rd Street station's bellmouth.<ref name="flickr20110922">{{cite web |title=Second Avenue Subway TBM Breakthrough 9/22/2011 |url=https://www.flickr.com/photos/mtaphotos/sets/72157627730112484/ |work=MTAPhotos |date=September 22, 2011 |publisher=Flickr |access-date=October 5, 2013 |archive-date=October 7, 2013 |archive-url=https://web.archive.org/web/20131007035727/http://www.flickr.com/photos/mtaphotos/sets/72157627730112484/ |url-status=live }}</ref><ref>{{cite web |url=http://www.capitalnewyork.com/article/politics/2011/09/3473217/second-avenue-subway-has-breakthrough-moment-several-billion-more-a?page=all |title=Second Avenue Subway has a breakthrough moment; several billion more are all the M.T.A. wants |work=Capital NY |last=Jose |first=Katharine |date=September 23, 2011 |access-date=May 27, 2014 |archive-url=https://web.archive.org/web/20140331174958/http://www.capitalnewyork.com/article/politics/2011/09/3473217/second-avenue-subway-has-breakthrough-moment-several-billion-more-a?page=all |archive-date=March 31, 2014 |url-status=dead }}</ref><ref name=":3" /><ref name=":8">{{cite web|url=http://www.mta.info/press-release/mta-headquarters/tunneling-second-avenue-subway-complete|title=Tunneling for Second Avenue Subway Complete|date=September 23, 2011|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|access-date=December 20, 2016|archive-date=August 22, 2016|archive-url=https://web.archive.org/web/20160822203928/http://www.mta.info/press-release/mta-headquarters/tunneling-second-avenue-subway-complete|url-status=dead}}</ref>

[[File:Second Avenue Subway Community Information Center vc.jpg|thumb|Second Avenue Subway Community Information Center for Phase 1]]

In July 2013, the MTA opened a [[86th Street (Second Avenue Subway)#Second Avenue Subway Community Information Center|Second Avenue Subway Community Information Center]] for Phase 1<ref>{{cite web|url=http://www.dnainfo.com/new-york/20130726/upper-east-side/mta-opens-second-avenue-subway-community-information-center|title=MTA Opens Second Avenue Subway Community Information Center|last=Bekiempis|first=Victoria|date=July 26, 2013|website=DNAinfo|access-date=May 19, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140519205107/http://www.dnainfo.com/new-york/20130726/upper-east-side/mta-opens-second-avenue-subway-community-information-center|archive-date=May 19, 2014}}</ref> at 1628 Second Avenue between 84th and [[85th Street]]s.<ref>{{cite web|url=http://web.mta.info/capital/cic_sas_alt.html|title=mta.info {{pipe}} Capital Programs Second Avenue Subway|publisher=MTA.info|access-date=May 19, 2014|archive-date=May 11, 2014|archive-url=https://web.archive.org/web/20140511062805/http://web.mta.info/capital/cic_sas_alt.html|url-status=live}}</ref> In the three years that followed, the center was visited over 20,000 times.<ref name=":50">{{Cite web|url=http://pix11.com/2017/04/24/information-center-opening-in-may-for-next-phase-of-second-avenue-subway/|title=Information center opening in May for next phase of Second Avenue Subway|last=Mocker|first=Greg|date=April 25, 2017|website=New York's PIX11 / WPIX-TV|access-date=April 25, 2017|archive-date=April 25, 2017|archive-url=https://web.archive.org/web/20170425084601/http://pix11.com/2017/04/24/information-center-opening-in-may-for-next-phase-of-second-avenue-subway/|url-status=live}}</ref> The final contract for Phase 1 was awarded in June 2013.<ref>{{cite press release |title=MTA Awards Final Contract to Build Phase&nbsp;1 of the Second Avenue Subway |publisher=Metropolitan Transportation Authority |date=June 13, 2013 |url=http://www.mta.info/press-release/mta-headquarters/mta-awards-final-contract-build-phase-1-second-avenue-subway |access-date=November 15, 2015 |archive-date=November 17, 2015 |archive-url=https://web.archive.org/web/20151117063330/http://www.mta.info/press-release/mta-headquarters/mta-awards-final-contract-build-phase-1-second-avenue-subway |url-status=dead }}</ref>  Blasting for the station caverns was finished in November 2013, and the muck houses were taken down at around the same time.<ref>{{cite web |last=Mann |first=Ted |title=Blasting Completed on Second Avenue Subway Project |website=The Wall Street Journal |date=November 22, 2013 |url=https://blogs.wsj.com/metropolis/2013/11/22/blasting-completed-on-second-avenue-subway-project/ |access-date=November 15, 2015 |archive-date=February 26, 2024 |archive-url=https://web.archive.org/web/20240226010634/https://www.wsj.com/articles/BL-METROB-19159 |url-status=live }}</ref> In late 2013, many of the tracks and signal panels began to arrive at the construction site, to be installed on the line over the next few years.<ref name="report q4 2013">{{cite web|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|url=http://web.mta.info/capital/sas_docs/Second%20Avenue%20Subway-%20Quarterly%20Report%202013%20Q4.pdf|title=Second Avenue Subway Quarterly Report Q4 2013|date=2013|access-date=December 17, 2016|archive-date=February 27, 2017|archive-url=https://web.archive.org/web/20170227124403/http://web.mta.info/capital/sas_docs/Second%20Avenue%20Subway-%20Quarterly%20Report%202013%20Q4.pdf|url-status=live}}</ref>

In February 2016, the MTA allocated $66&nbsp;million to speed up the construction of the first phase so that it could open in December.<ref>{{cite web|last=Weaver|first=Shaye|date=February 24, 2016|url=https://www.dnainfo.com/new-york/20160224/upper-east-side/mta-will-tap-into-back-up-fund-finish-second-ave-subway-on-time-board|title=MTA Will Tap Into Back-Up Fund to Finish Second Ave. Subway On Time: Board|work=DNAinfo New York|access-date=March 6, 2016|url-status=dead|archive-url=https://web.archive.org/web/20160227220344/https://www.dnainfo.com/new-york/20160224/upper-east-side/mta-will-tap-into-back-up-fund-finish-second-ave-subway-on-time-board|archive-date=February 27, 2016}}</ref> Concerns about the line's timely opening persisted through October and November.<ref>{{Cite news|url=http://www.nydailynews.com/new-york/manhattan/ave-subway-december-2016-opening-deadline-article-1.2466180|title=Second Ave. subway may miss December 2016 opening deadline|last=Rivoli|first=Dan|date=December 15, 2015|newspaper=NY Daily News|access-date=October 27, 2016|archive-date=October 27, 2016|archive-url=https://web.archive.org/web/20161027123948/http://www.nydailynews.com/new-york/manhattan/ave-subway-december-2016-opening-deadline-article-1.2466180|url-status=live}}</ref><ref name=":53">{{Cite news|url=https://www.nytimes.com/2016/11/15/nyregion/second-avenue-subway-opening.html|title='Unprecedented' Work Required to Open 2nd Avenue Subway by Year's End, Officials Say|last=Fitzsimmons|first=Emma G.|date=November 14, 2016|newspaper=The New York Times|issn=0362-4331|access-date=November 17, 2016|archive-date=November 16, 2016|archive-url=https://web.archive.org/web/20161116012336/http://www.nytimes.com/2016/11/15/nyregion/second-avenue-subway-opening.html|url-status=live}}</ref> Test trains started running on October 9, 2016,<ref>{{cite news|url=http://www.nydailynews.com/new-york/manhattan/mta-finally-testing-trains-ave-subway-tracks-article-1.2825671|title=SEE IT: MTA finally testing trains along Second Ave. subway line|last=Rivoli|first=Dan|date=October 10, 2016|newspaper=New York Daily News|access-date=October 10, 2016|archive-date=October 11, 2016|archive-url=https://web.archive.org/web/20161011060723/http://www.nydailynews.com/new-york/manhattan/mta-finally-testing-trains-ave-subway-tracks-article-1.2825671|url-status=live}}</ref> and out-of-service Q trains started running through the subway in November 2016.<ref>{{cite web|url=http://www.ny1.com/nyc/all-boroughs/transit/2016/09/16/sources--mta-powered-third-rail-for-testing-on-second-avenue-subway-tracks.html|title=Sources: MTA Powered Third Rail for Testing on Second Avenue Subway Tracks|date=September 16, 2016|website=TWC News|access-date=September 18, 2016|archive-date=September 22, 2016|archive-url=https://web.archive.org/web/20160922160938/http://www.ny1.com/nyc/all-boroughs/transit/2016/09/16/sources--mta-powered-third-rail-for-testing-on-second-avenue-subway-tracks.html|url-status=live}}</ref> The new Third Avenue entrance to the Lexington Avenue–63rd Street station opened on December 30, 2016.<ref name="86th-openhouse">{{Cite web|url=http://www.mta.info/news/2016/12/30/governor-cuomo-debuts-new-86th-street-subway-station-and-new-entrance-63rd-street|title=Governor Cuomo Debuts New 86th Street Subway Station and New Entrance at 63rd Street Subway Station|date=December 30, 2016|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=December 31, 2016|archive-date=January 19, 2021|archive-url=https://web.archive.org/web/20210119090649/https://www.mta.info/news/2016/12/30/governor-cuomo-debuts-new-86th-street-subway-station-and-new-entrance-63rd-street|url-status=dead}}</ref> The ceremonial first train, with several prominent officials in attendance, ran on New Year's Eve,<ref>{{Cite news|url=http://gothamist.com/2017/01/01/governor_cuomo_throws_second_avenue.php#photo-4|title=Governor Cuomo Throws Second Avenue Subway Party For The First (Private) Ride|last=Chung|first=Jen|date=January 1, 2017|newspaper=Gothamist|language=en-US|access-date=January 1, 2017|url-status=dead|archive-url=https://web.archive.org/web/20170104023830/http://gothamist.com/2017/01/01/governor_cuomo_throws_second_avenue.php#photo-4|archive-date=January 4, 2017}}</ref><ref>{{Cite news|url=http://www.amny.com/transit/second-avenue-subway-s-inaugural-ride-on-new-year-s-eve-to-include-cuomo-de-blasio-1.12808319|title=Cuomo, de Blasio to take 1st ride on 2nd Ave. subway|last=Barone|first=Vincent|date=December 26, 2016|newspaper=am New York|access-date=December 27, 2016|archive-date=December 27, 2016|archive-url=https://web.archive.org/web/20161227124446/http://www.amny.com/transit/second-avenue-subway-s-inaugural-ride-on-new-year-s-eve-to-include-cuomo-de-blasio-1.12808319|url-status=live}}</ref> and regular service began at noon the next day.<ref name=":1" /><ref name=":41" /><ref name=":42" /> About 48,200 passengers entered the new stations on January 1, excluding passengers who toured the line by entering at a station in the rest of the system.<ref>{{cite web | title=Second Avenue subway's New Year's Day opening drew 48,200 | first=Vincent | last=Barone | website=am New York | date=January 2, 2017 | url=http://www.amny.com/transit/second-avenue-subway-draws-thousands-of-riders-for-new-year-s-day-opening-1.12842779 | access-date=January 3, 2017 | archive-date=December 5, 2019 | archive-url=https://web.archive.org/web/20191205040238/https://www.amny.com/transit/second-avenue-subway-draws-thousands-of-riders-for-new-year-s-day-opening-1.12842779/ | url-status=live }}</ref>

[[File:86th Street Station Second Avenue SAS 3975.jpg|thumb|right|Opening day at [[86th Street (Second Avenue Subway)|86th Street]]]]

Because of the opening of Phase 1, ridership on the Lexington Avenue Line at the [[68th Street–Hunter College (IRT Lexington Avenue Line)|68th Street]], [[77th Street (IRT Lexington Avenue Line)|77th Street]], [[86th Street (IRT Lexington Avenue Line)|86th Street]], and [[96th Street (IRT Lexington Avenue Line)|96th Street]] stations decreased in January 2017 compared to January 2016.<ref name=":49" /><ref>{{Cite web|url=http://www.mta.info/news/2017/02/01/second-av-subway-ridership-growing-rapidly|title=Second Av Subway Ridership Growing Rapidly|date=February 1, 2017|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=February 1, 2017|archive-date=May 21, 2017|archive-url=https://web.archive.org/web/20170521012108/http://www.mta.info/news/2017/02/01/second-av-subway-ridership-growing-rapidly|url-status=dead}}</ref> The Second Avenue Line's three stations and the renovated Lexington Avenue–63rd Street station saw an average weekday ridership of more than 150,000 by the end of January. The 72nd Street station was the busiest of the line's new stations, with an average daily ridership of 44,000.<ref name=":49">{{Cite news|url=https://www.nytimes.com/2017/02/01/nyregion/second-avenue-subway-relieves-crowding-on-neighboring-lines.html|title=Second Avenue Subway Relieves Crowding on Neighboring Lines|last1=Fitzsimmons|first1=Emma G.|date=February 1, 2017|last2=Sun|first2=Albert|newspaper=The New York Times|issn=0362-4331|access-date=February 1, 2017|archive-date=February 2, 2017|archive-url=https://web.archive.org/web/20170202115330/https://www.nytimes.com/2017/02/01/nyregion/second-avenue-subway-relieves-crowding-on-neighboring-lines.html|url-status=live}}</ref> By April, taxi usage in the area also saw a decline of more than 20% compared to before the line's opening.<ref>{{Cite web|url=https://www.dnainfo.com/new-york/20170419/upper-east-side/second-avenue-subway-taxi-use-declines-lenox-hill-yorkville|title=Taxi Use Plummets on Upper East Side Due to 2nd Avenue Subway, Report Finds|last=Weaver|first=Shaye|date=April 19, 2017|website=DNAinfo New York|archive-url=https://web.archive.org/web/20170426063214/https://www.dnainfo.com/new-york/20170419/upper-east-side/second-avenue-subway-taxi-use-declines-lenox-hill-yorkville|archive-date=April 26, 2017|url-status=dead|access-date=April 25, 2017}}</ref><ref>{{Cite news|url=http://wagner.nyu.edu/rudincenter/wp-content/uploads/2017/04/SASandTaxis.pdf|title=Upper East Side Taxis and the Second Avenue Subway|last1=Kaufman|first1=Sarah|date=April 18, 2017|work=[[Rudin Center for Transportation Policy & Management|NYU Rudin Center for Transportation]]|access-date=April 25, 2017|archive-url=https://web.archive.org/web/20170426063200/http://wagner.nyu.edu/rudincenter/wp-content/uploads/2017/04/SASandTaxis.pdf|archive-date=April 26, 2017|url-status=dead|last2=Kaputkin|first2=Ari|language=en-US}}</ref>

By February 2018, there were 190,000 riders per weekday, within the 5% margin of error for the 200,000-daily-rider estimate given in the Environmental Impact Statement. Rush-hour ridership was within 2% of projections.<ref>{{Cite web|url=http://web.mta.info/sandy/pdf/20180222CrosstownTrafficAnalysis_.pdf|title=14th Street Corridor Traffic Analysis Overview|date=February 22, 2018|website=Metropolitan Transit Authority|access-date=February 25, 2018|page=7|archive-date=April 14, 2018|archive-url=https://web.archive.org/web/20180414172050/http://web.mta.info/sandy/pdf/20180222CrosstownTrafficAnalysis_.pdf|url-status=live}}</ref> In November 2017, because of the increasing demand, Q service was increased by one trip during each rush hour, and one northbound R trip was rerouted from the [[IND Queens Boulevard Line]] to further boost service.<ref name=":33">{{Cite web|url=https://transitfeeds.com/p/mta/79/latest/trip/B20171105WKD_042100_R..N76R|title=7:01 AM – 8:05 AM 96 ST – TransitFeeds|date=November 6, 2017|website=transitfeeds.com|access-date=November 6, 2017|archive-url=https://web.archive.org/web/20171107061149/https://transitfeeds.com/p/mta/79/latest/trip/B20171105WKD_042100_R..N76R|archive-date=November 7, 2017|url-status=dead}}</ref> This trip returns southbound in Q service.<ref name="serviceincrease">{{Cite news|url=http://www.nydailynews.com/new-york/mta-add-q-trains-ave-subway-line-ridership-soars-article-1.3186366|title=MTA to add Q trains on Second Ave. subway line as ridership soars|last=Rivoli|first=Dan|date=May 22, 2017|work=New York Daily News|access-date=May 22, 2017|archive-date=May 25, 2017|archive-url=https://web.archive.org/web/20170525132220/http://www.nydailynews.com/new-york/mta-add-q-trains-ave-subway-line-ridership-soars-article-1.3186366|url-status=live}}</ref><ref name=":9" />

===<span class="anchor" id="Phase 2"></span>Phase 2 construction===
{{details|Construction of the Second Avenue Subway#2016–present: Second phase}}
[[File:2nd Ave & 106th St.jpg|thumb|right|The location of the planned Phase 2 station at 106th Street and Second Avenue]]

The second phase, between 125th and 96th Streets, was allocated $535&nbsp;million in the MTA's 2015–2019 Capital Plan for planning, design, environmental studies and utility relocation.<ref name="Fitzsimmons 2015">{{cite news|url=https://www.nytimes.com/2015/10/30/nyregion/anger-in-east-harlem-over-new-delays-in-2nd-ave-subway-plans.html|title=Anger in East Harlem Over New Delays in 2nd Ave. Subway Plans|last=Fitzsimmons|first=Emma G.|date=October 29, 2015|website=The New York Times|access-date=November 3, 2015|archive-date=November 3, 2015|archive-url=https://web.archive.org/web/20151103014702/https://www.nytimes.com/2015/10/30/nyregion/anger-in-east-harlem-over-new-delays-in-2nd-ave-subway-plans.html|url-status=live}}</ref><ref name="MTACapital-15-19-Oct2015">{{cite web|url=http://web.mta.info/capital/pdf/CapitalProgram2015-19_WEB%20v4%20FINAL_small.pdf|title=MTA Capital Program 2015–2019: Renew. Enhance. Expand.|date=October 28, 2015|publisher=[[Metropolitan Transportation Authority]]|access-date=October 28, 2015|archive-date=November 6, 2015|archive-url=https://web.archive.org/web/20151106022734/http://web.mta.info/capital/pdf/CapitalProgram2015-19_WEB%20v4%20FINAL_small.pdf|url-status=live}}</ref> Three new stations will be constructed at 125th Street, 116th Street and 106th Street. A transfer to the Lexington Avenue Line and an intermodal connection with [[Metro-North Railroad]] would be available at the Harlem–125th Street station.<ref name="MTA-SEASCh2"/>{{rp|11,12}}

The original plan called for the main line to turn west onto 125th Street with [[pocket track|tail tracks]] to [[Fifth Avenue]],<ref name=":6">{{cite web|url=http://web.mta.info/capital/pdf/MTA_15-19_Capital_Plan_Board_WEB_Approved_v2.pdf|title=MTA Capital Program 2015 – 2019 Capital Plan Renew. Enhance. Expand. As Approved by MTA Board April 20, 2016. As Approved by the CPRB May 23, 2016.|date=May 2016|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 7, 2016|archive-date=November 10, 2016|archive-url=https://web.archive.org/web/20161110142705/http://web.mta.info/capital/pdf/MTA_15-19_Capital_Plan_Board_WEB_Approved_v2.pdf|url-status=live}}</ref> while tail tracks would continue north on a spur via Second Avenue to 129th Street.<ref name="deis2" /><ref>{{Cite web|url=http://web.mta.info/nyct/procure/contracts/127485INFOsol.pdf|title=CM-1190 Consultant Design Services for Phase 2 of the Second Avenue Subway Project|date=March 4, 2016|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 27, 2017|archive-date=January 6, 2017|archive-url=https://web.archive.org/web/20170106193624/http://web.mta.info/nyct/procure/contracts/127485INFOsol.pdf|url-status=live}}</ref> However, the tail tracks to 129th Street, as well as a proposed ancillary building at 127th Street and Second Avenue, were removed in a June 2018 update to the plans. The change in tail tracks was made because it was found that providing tail tracks at the line's terminal will more efficiently facilitate subway service.<ref name=":4">{{Cite web|url=http://web.mta.info/capital/sas_pdf/2018Nov15SASPhase2FONSIattachmentA.pdf|title=FINDING OF NO SIGNIFICANT IMPACT Attachment A: Summary of Comments and Responses|date=November 15, 2018|website=mta.info|publisher=Federal Transit Administration|access-date=November 19, 2018|archive-date=November 19, 2018|archive-url=https://web.archive.org/web/20181119213619/http://web.mta.info/capital/sas_pdf/2018Nov15SASPhase2FONSIattachmentA.pdf|url-status=live}}</ref>{{Rp|23}}

A bellmouth provision for extension to the Bronx remains, though shifted closer to the 116th Street station at 118th Street.<ref name="MTA-SEASCh2">{{cite book|url=http://web.mta.info/capital/sas_docs/ea_phase2/02_Description_of_Phase_2_Modified_Design-07-2018.pdf|title=Supplemental Environmental Assessment to the Second Avenue Subway Final Environmental Impact Statement: Phase 2|chapter=Chapter 2: Description of Phase 2 Modified Design|publisher=Metropolitan Transportation Authority|date=July 2018|access-date=July 13, 2018|archive-date=July 13, 2018|archive-url=https://web.archive.org/web/20180713020232/http://web.mta.info/capital/sas_docs/ea_phase2/02_Description_of_Phase_2_Modified_Design-07-2018.pdf|url-status=live}}</ref>{{rp|12}} Here, two outer tracks will head west toward 125th Street while space for two inner tracks will allow for an extension to the Bronx.<ref name=":4" />{{Rp|24}} North of 120th Street, the line will be constructed through the use of TBMs. South of 120th Street, the line will utilize the 99th–105th and 110th–120th Streets tunnel sections built during the 1970s, with a cut-and-cover tunnel connecting the segments between 105th and 110th Streets.<ref name="MTA-SASFEISCh3" />{{Rp|2}}<ref name=":52">{{Cite web|url=http://web.mta.info/mta/news/books/pdf/170320_1345_CPOC.pdf#page=46|title=MTACC REPORT TO CPOC SECOND AVENUE SUBWAY – PHASE 2|date=March 20, 2017|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 27, 2017|archive-date=August 28, 2017|archive-url=https://web.archive.org/web/20170828062241/http://web.mta.info/mta/news/books/pdf/170320_1345_CPOC.pdf#page=46|url-status=live}}</ref>{{Rp|45}}

The Phase 2 budget was originally $1.5&nbsp;billion, which would be used to start construction of the tunnels. The MTA reduced the amount of money allocated in the budget, projecting that the agency would not be able to start construction by the end of the 5-year cycle in 2019.<ref name="nydailynews2015">{{cite web|url=http://www.nydailynews.com/new-york/mta-propose-1-5b-2nd-ave-subway-article-1.1895922|title=MTA to propose $1.5B to Phase 2 of 2nd Ave. subway construction|location=New York|work=Daily News|date=August 7, 2014|first=Pete|last=Donohue|access-date=December 23, 2016|archive-date=January 6, 2017|archive-url=https://web.archive.org/web/20170106193000/http://www.nydailynews.com/new-york/mta-propose-1-5b-2nd-ave-subway-article-1.1895922|url-status=live}}</ref><ref>{{cite web|url=http://ny.curbed.com/archives/2014/08/07/second_avenue_subway_gets_15b_for_phase_2_construction.php|title=Second Avenue Subway Gets $1.5B for Phase 2 Construction|work=Curbed NY|last=Dailey|first=Jessica|date=August 7, 2014|access-date=August 10, 2014|archive-date=September 9, 2015|archive-url=https://web.archive.org/web/20150909023730/http://ny.curbed.com/archives/2014/08/07/second_avenue_subway_gets_15b_for_phase_2_construction.php|url-status=live}}</ref> In April 2016, the MTA and the State of New York reached a deal to restore funding to Phase 2, with a total of $1.035&nbsp;billion allocated.<ref>{{cite news|url=https://www.nytimes.com/2016/04/21/nyregion/mta-spending-plan-restores-funding-for-2nd-ave-subway.html?_r=0|title=M.T.A. Spending Plan Restores Funding for 2nd Ave. Subway|last=Fitzsimmons|first=Emma G.|date=April 20, 2016|newspaper=New York Times|location=New York|access-date=May 16, 2016|archive-date=August 28, 2017|archive-url=https://web.archive.org/web/20170828063544/https://www.nytimes.com/2016/04/21/nyregion/mta-spending-plan-restores-funding-for-2nd-ave-subway.html?_r=0|url-status=live}}</ref> This budget was raised by $700&nbsp;million in May 2017.<ref>{{Cite web|url=http://web.mta.info/mta/news/books/docs/May%20Board%20Presentation_Board.pdf|title=MTA Capital Program Amendments Renew. Enhance. Expand. Capital Program Briefing May 2017|date=May 24, 2017|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=May 24, 2017|archive-date=August 28, 2017|archive-url=https://web.archive.org/web/20170828102145/http://web.mta.info/mta/news/books/docs/May%20Board%20Presentation_Board.pdf|url-status=live}}</ref> By August 2017, preliminary work on the line was underway,<ref name=":52" />{{Rp|48}}<ref>{{Cite web|url=https://www.akrf.com/integrated-approach/transportation/projects/nyc-mta-second-avenue-subway/|title=Second Avenue Subway|website=AKRF, Inc.|access-date=August 27, 2017|archive-date=November 20, 2018|archive-url=https://web.archive.org/web/20181120095443/https://www.akrf.com/integrated-approach/transportation/projects/nyc-mta-second-avenue-subway/|url-status=live}}</ref> and design of the project was being performed by Phase 2 Partnership, a joint venture of Parsons-Brinckerhoff and STV.<ref>{{Cite web|url=http://web.mta.info/capconstr/procurement/cc_recentawards.htm|title=MTA Capital Construction – Procurement|website=web.mta.info|publisher=Metropolitan Transportation Authority|language=en|archive-url=https://web.archive.org/web/20170827234406/http://web.mta.info/capconstr/procurement/cc_recentawards.htm|archive-date=August 27, 2017|url-status=live|access-date=August 27, 2017}}</ref> The EIS and design were finished in 2018.<ref name=":52" />{{Rp|46}} In July 2018, the MTA published a Supplemental Environmental Assessment for the SAS FEIS. The FTA issued a [[National Environmental Policy Act|Finding of No Significant Impact]] for the project on November 15, 2018.<ref>{{Cite web|url=http://web.mta.info/capital/sas_pdf/2018Nov15SASPhase2FONSI.pdf|title=Finding of No Significant Impact (FONSI) for the Second Avenue Subway Phase 2|date=November 15, 2018|website=mta.info|publisher=Federal Transit Administration|access-date=November 19, 2018|archive-date=November 19, 2018|archive-url=https://web.archive.org/web/20181119213600/http://web.mta.info/capital/sas_pdf/2018Nov15SASPhase2FONSI.pdf|url-status=live}}</ref><ref>{{cite web | title=Milestone reached in Second Avenue subway project | website=Crain's New York Business | last=Beltran | first=Lizeth | date=November 19, 2018 | url=https://www.crainsnewyork.com/transportation/milestone-reached-second-avenue-subway-project | access-date=November 19, 2018 | archive-date=June 2, 2019 | archive-url=https://web.archive.org/web/20190602194838/https://www.crainsnewyork.com/transportation/milestone-reached-second-avenue-subway-project | url-status=live }}</ref>

A Second Avenue Subway Community Information Center for Phase 2, along 125th Street between Park and Madison Avenues, opened in September 2017, delayed by four months.<ref>{{cite web | last=Mocker | first=Greg | title=Information center opening in May for next phase of Second Avenue Subway | website=New York's PIX11 / WPIX-TV | date=April 25, 2017 | url=http://pix11.com/2017/04/24/information-center-opening-in-may-for-next-phase-of-second-avenue-subway/ | access-date=September 28, 2017 | archive-date=September 17, 2017 | archive-url=https://web.archive.org/web/20170917044338/http://pix11.com/2017/04/24/information-center-opening-in-may-for-next-phase-of-second-avenue-subway/ | url-status=live }}</ref><ref name=":50" /><ref>{{cite web|url=http://www.ny1.com/nyc/all-boroughs/transit/2017/09/22/new-center-gives-glimpse-of-second-avenue-subway-s-future.html|title=New center gives glimpse of Second Avenue Subway's future|last=Martinez|first=Jose|date=September 22, 2017|website=NY1.com|archive-url=https://web.archive.org/web/20170923072307/http://www.ny1.com/nyc/all-boroughs/transit/2017/09/22/new-center-gives-glimpse-of-second-avenue-subway-s-future.html|archive-date=September 23, 2017|url-status=live|access-date=September 28, 2017}}</ref> The [[administration of Joe Biden]] approved funding for Phase 2 of the Second Avenue Subway in November 2021,<ref name="Crain's New York Business 2021">{{cite web | title=Washington's $1.2T infrastructure bill boosts 5 NYC transportation projects | website=Crain's New York Business | last=Pascus | first=Brian | date=November 8, 2021 | url=https://www.crainsnewyork.com/transportation/5-transportation-projects-thatll-get-boost-bidens-12t-infrastructure-bill | access-date=November 26, 2021 | archive-date=November 26, 2021 | archive-url=https://web.archive.org/web/20211126180452/https://www.crainsnewyork.com/transportation/5-transportation-projects-thatll-get-boost-bidens-12t-infrastructure-bill | url-status=live }}</ref> and land acquisition for Phase 2 started in April 2022.<ref name="Garber 2022">{{cite web | last=Garber | first=Nick | title=125th Street Building Seized By MTA For Second Avenue Subway | website=Harlem, NY Patch | date=April 19, 2022 | url=https://patch.com/new-york/harlem/125th-street-building-seized-mta-second-avenue-subway | access-date=April 19, 2022 | archive-date=July 11, 2022 | archive-url=https://web.archive.org/web/20220711143935/https://patch.com/new-york/harlem/125th-street-building-seized-mta-second-avenue-subway | url-status=live }}</ref> The MTA began soliciting bids for the first construction contracts in July 2023, and estimated that construction would start by the end of the year.<ref name="Simko-Bednarski 2023 b422">{{cite web |last=Simko-Bednarski |first=Evan |date=July 5, 2023 |title=MTA seeks contracts for Harlem phase of NYC Second Ave. subway |url=https://www.nydailynews.com/new-york/ny-second-avenue-subway-phase-two-20230705-cimmuqdqc5dnrb2tfqhqpuz6ue-story.html |access-date=July 5, 2023 |website=New York Daily News |archive-date=July 5, 2023 |archive-url=https://web.archive.org/web/20230705193054/https://www.nydailynews.com/new-york/ny-second-avenue-subway-phase-two-20230705-cimmuqdqc5dnrb2tfqhqpuz6ue-story.html |url-status=live }}</ref><ref name="Saltonstall 2023 m514">{{cite web |last=Saltonstall |first=Gus |date=July 5, 2023 |title=SEE IT: First-Ever Rendering Of 2nd Ave East Harlem Subway Extension |url=https://patch.com/new-york/harlem/see-it-first-ever-rendering-revealed-2nd-ave-east-harlem-extension |access-date=July 5, 2023 |website=Harlem, NY Patch |archive-date=July 5, 2023 |archive-url=https://web.archive.org/web/20230705193034/https://patch.com/new-york/harlem/see-it-first-ever-rendering-revealed-2nd-ave-east-harlem-extension |url-status=live }}</ref> The MTA stated it would reduce the cost of Phase 2 by at least $1 billion through methods such as constructing smaller stations and platforms while also reutilizing tunnels built in the 1970s rather than demolishing them.<ref>{{cite news |url=https://new.mta.info/document/131306 |title=Second Avenue Subway: Phase 2 Technical Briefing |work=MTA.info |date=January 22, 2024 |access-date=January 23, 2024 |archive-date=January 23, 2024 |archive-url=https://web.archive.org/web/20240123015803/https://new.mta.info/document/131306 |url-status=live }}</ref> Although the MTA awarded an $182 million contract in January 2024 to relocate utilities,<ref>{{cite web | last=Paolicelli | first=Alyssa | title=Uncertainty over the Second Avenue subway extension | website=Spectrum News NY1  | date=June 11, 2024 | url=https://ny1.com/nyc/manhattan/transit/2024/06/11/uncertainty-over-the-second-avenue-subway-extension | access-date=June 18, 2024}}</ref> work on that contract was delayed after Governor [[Kathy Hochul]] paused the implementation of [[congestion pricing in New York City]] in June 2024.<ref>{{cite web | last=Brachfeld | first=Ben | title=Congestion pricing: Work completely halted on Second Avenue Subway extension following Hochul pause | website=amNewYork | date=June 18, 2024 | url=https://www.amny.com/transit/congestion-pricing-work-second-avenue-subway-extension/ | access-date=June 18, 2024}}</ref>

==={{anchor|Other phases}}Phases 3 and 4===
Phase 3, which has no funding commitments, would extend the line southward along Second Avenue from 63rd Street to Houston Street.<ref name="nydailynews 1">{{cite news|url=http://www.nydailynews.com/new-york/ave-subway-track-open-2016-mta-article-1.1251331|title=Second Ave. subway on track to open in 2016: MTA|last=Donohue|first=Pete|date=January 20, 2013|newspaper=New York Daily News|access-date=March 25, 2013|archive-date=February 3, 2013|archive-url=https://web.archive.org/web/20130203064444/http://www.nydailynews.com/new-york/ave-subway-track-open-2016-mta-article-1.1251331|url-status=live}}</ref> Upon its completion, a new service will operate running between 125th and Houston Streets. Phases 2 and 3, classified as a high-priority project by [[Infrastructure policy of Donald Trump|the Trump administration]], may cost up to a combined total of $14.2&nbsp;billion.<ref name=":47">{{Cite web|last=Mocker|first=Greg|url=http://pix11.com/2017/01/26/second-avenue-subway-expansion-to-be-added-to-trumps-infrastructure-priority-congresswoman-says/|title=Second Avenue Subway expansion to be added to Trump's infrastructure priorities, congresswoman says|date=January 27, 2017|website=New York's PIX11 / WPIX-TV|access-date=January 27, 2017|archive-date=January 27, 2017|archive-url=https://web.archive.org/web/20170127045433/http://pix11.com/2017/01/26/second-avenue-subway-expansion-to-be-added-to-trumps-infrastructure-priority-congresswoman-says/|url-status=live}}</ref><ref name=":48">{{Cite news|last=Fox|first=Alison|date=January 26, 2017|url=http://www.amny.com/transit/second-avenue-subway-a-priority-for-trump-rep-maloney-says-1.13020262|title=Maloney: Second Ave. subway is a priority for Trump|newspaper=am New York|access-date=January 27, 2017|language=en|archive-date=January 26, 2017|archive-url=https://web.archive.org/web/20170126215629/http://www.amny.com/transit/second-avenue-subway-a-priority-for-trump-rep-maloney-says-1.13020262|url-status=live}}</ref>

Phase 4, which also has no funding commitments,<ref name="nydailynews 1" /> will provide an extension from Houston Street to a permanent terminus, with storage tracks, at [[Hanover Square (Manhattan)|Hanover Square]]. These storage tracks, initially recommended in the SDEIS, would allow for the storage of four trains, and they would run south of Hanover Square from [[Coenties Slip]] to a traffic island near [[Peter Minuit Plaza]] at a depth of {{Convert|110|feet|meters}}.<ref name="MTA-SASFEISCh2" />{{rp|16}} The Hanover Square terminal is only planned to be able to turn back 26 trains per hour instead of 30 as less capacity will be needed on the line south of 63rd Street.<ref name="MTA-SASFEISCh2">{{cite web|url=http://web.mta.info/capital/sas_docs/feis/chapter02.pdf|title=Second Avenue Subway Final Environmental Impact Statement (FEIS): Chapter 2: Project Alternatives|date=May 2004|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|access-date=August 5, 2015|archive-date=October 5, 2018|archive-url=https://web.archive.org/web/20181005164409/http://web.mta.info/capital/sas_docs/feis/chapter02.pdf|url-status=live}}</ref>{{rp|26}} The Hanover Square station will be deep enough to allow for the potential extension of Second Avenue Subway service to Brooklyn through a new tunnel under the East River.<ref name="deis2">{{cite web|url=http://web.mta.info/capital/sas_docs/sdeis/chapter2.pdf|title=Second Avenue Subway Supplemental Draft Environmental Impact Statement (SDEIS), April 2003 Chapter 2 Project Alternatives|date=April 2003|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 9, 2016|archive-date=December 5, 2019|archive-url=https://web.archive.org/web/20191205040239/http://web.mta.info/capital/sas_docs/sdeis/chapter2.pdf|url-status=live}}</ref>

==Design and cost==
===Features===
The stations on the line were built to be wider than most other underground subway stations in the system.<ref>{{cite web|url=https://gizmodo.com/a-subterranean-stroll-through-nycs-newest-train-tunnel-1570826409|title=A Subterranean Stroll Through NYC's Newest Train Tunnel|author=Hession, Michael|date=May 2, 2014|work=[[Gizmodo]]|access-date=May 13, 2014|archive-date=May 13, 2014|archive-url=https://web.archive.org/web/20140513075213/http://gizmodo.com/a-subterranean-stroll-through-nycs-newest-train-tunnel-1570826409|url-status=live}}</ref> Because of this, Horodniceanu likened the Second Avenue Subway stations to the stations on the [[Washington Metro]].<ref name="amny-20140501" /> All stations on the line feature {{Convert|615|feet|meters|adj=mid|-long}} platforms, with {{convert|800|-|1400|ft|abbr=on}} overall lengths to provide space for power stations and ventilation plants.<ref name="MTA-SASFEISCh3">{{cite web|url=http://web.mta.info/capital/sas_docs/feis/chapter03.pdf#page=51|title=Second Avenue Subway Final Environmental Impact Statement (FEIS): Chapter 3: Description of Construction Methods and Activities|date=May 2004|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|access-date=August 5, 2015|archive-date=April 19, 2020|archive-url=https://web.archive.org/web/20200419105357/http://web.mta.info/capital/sas_docs/feis/chapter03.pdf#page=51|url-status=live}}</ref>{{Rp|14}} Tracks are built on rubber pads, which reduces noise from trains.<ref>{{cite web|url=https://www.wsj.com/articles/sneaking-a-peek-at-the-second-avenue-subway-line-1466385416|title=Sneaking a Peek at the Second Avenue Subway Line|last=Kanno-Youngs|first=Zolan|date=June 19, 2016|website=WSJ|publisher=Wall Street Journal|access-date=June 20, 2016|archive-date=June 20, 2016|archive-url=https://web.archive.org/web/20160620090409/http://www.wsj.com/articles/sneaking-a-peek-at-the-second-avenue-subway-line-1466385416|url-status=live}}</ref>

In August 2006, the MTA revealed that all future subway stations—including stations on the Second Avenue Subway and the [[7 Subway Extension]], as well as the new [[South Ferry/Whitehall Street (New York City Subway)|South Ferry]] station—would be outfitted with air-cooling systems to reduce the temperature along platforms by as much as {{convert|10|F-change|0}}.<ref>{{cite news|url=http://www.nydailynews.com/news/2006/08/04/2006-08-04_cooler_subways_coming__eventually.html|title=Cooler Subways Coming Eventually|last=Donohue|first=Pete|date=August 4, 2006|newspaper=[[New York Daily News]]|access-date=December 12, 2008|archive-url=https://web.archive.org/web/20071010000252/http://www.nydailynews.com/news/2006/08/04/2006-08-04_cooler_subways_coming__eventually.html|archive-date=October 10, 2007}}</ref> In early plans, the Second Avenue Subway was also to have [[platform screen doors]] to assist with air-cooling, energy savings, ventilation, and track safety,<ref>{{Cite news|url=https://www.nytimes.com/2007/04/05/nyregion/05doors.html|title=2nd Ave. Subway Platforms May Get Glass Walls and Sliding Doors|last=Neuman|first=William|date=April 5, 2007|newspaper=The New York Times|issn=0362-4331|access-date=January 12, 2017|archive-date=April 22, 2017|archive-url=https://web.archive.org/web/20170422012313/http://www.nytimes.com/2007/04/05/nyregion/05doors.html|url-status=live}}</ref> but this plan was scrapped in 2012 as cost-prohibitive.<ref>{{cite news|url=https://www.politico.com/states/new-york/city-hall/story/2012/12/no-seoul-style-platform-doors-for-new-york-subways-even-in-new-stations-000000|title=No Seoul-style platform doors for New York subways, even in new stations|work=Politico|date=December 7, 2012|first=Dana|last=Rubinstein|access-date=February 24, 2020|archive-date=February 24, 2020|archive-url=https://web.archive.org/web/20200224011048/https://www.politico.com/states/new-york/city-hall/story/2012/12/no-seoul-style-platform-doors-for-new-york-subways-even-in-new-stations-000000|url-status=live}}</ref> Stations constructed as part of Phase 2 may receive platform screen doors depending on the results of studies being conducted for their installation elsewhere.<ref name=":4" />{{Rp|15}}

=== Construction methods ===
The construction of the {{convert|8.5|mi|km|sp=us}} of the Second Avenue Subway underneath densely populated Manhattan will require the use of several construction methods, depending on the section of the line.<ref name="sdeis3" /><ref name="ConstructionTechniques" /> The line's tunnels will largely consist of twin tunnels with diameters of up to {{Convert|23.5|feet|meters}}.<ref name="MTA-SASFEISCh3" />{{Rp|1}} About 90% of the tunneling is to be performed by tunnel boring machines. The rest will be done using the cut-and-cover method, or through the use of mined drill-and-blast, for sections averaging {{convert|275|m|ft|sp=us}} in length, namely the station boxes.<ref name="sdeis3" /><ref name="ConstructionTechniques" /> The methods used to construct the sections of the line were confirmed in 2003, with a modification of the section north of 120th Street announced in 2016.<ref name="sdeis3">{{cite web|url=http://web.mta.info/capital/sas_docs/sdeis/chapter3.pdf|title=Second Avenue Subway SDEIS Chapter 3: Description of Construction Methods and Activities|date=April 2003|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 15, 2015|archive-date=September 9, 2015|archive-url=https://web.archive.org/web/20150909023730/http://web.mta.info/capital/sas_docs/sdeis/chapter3.pdf|url-status=live}}</ref><ref name="ConstructionTechniques">{{cite web |url=http://web.mta.info/capital/sas_docs/2ndave.pdf |title=Second Avenue Subway Construction Techniques |date=August 2002 |access-date=February 15, 2016 |website=mta.info |publisher=Metropolitan Transportation Authority |archive-date=August 19, 2014 |archive-url=https://web.archive.org/web/20140819154743/http://web.mta.info/capital/sas_docs/2ndave.pdf |url-status=live }}</ref>{{rp|2}}<ref name="cb11-20160405">{{Cite web|url=http://web.mta.info/capital/sas_pdf/Community%20Board%2011%20Presentation%204.5.16%20Final.pdf|title=Second Avenue Subway Update to Community Board 11|date=April 5, 2016|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=January 8, 2017|archive-date=March 16, 2017|archive-url=https://web.archive.org/web/20170316041839/http://web.mta.info/capital/sas_pdf/Community%20Board%2011%20Presentation%204.5.16%20Final.pdf|url-status=live}}</ref>{{rp|14}}

{| cellspacing="0" style="text-align:center; font-size: 86%; vertical-align:bottom;"
|-
| colspan=3 | '''Phases 1 & 2 '''
| colspan=3 | '''Phases 3 & 4 '''
|-
| style="width:39.75; height:27.75;"| Streets ||style="width:143.75;"| Construction method||style="width:143.75;"| Remarks
| style="border-left:9px solid white; width:39.75;"| Streets || style="width:143.75;"| Construction method ||style="width:143.75;"| Remarks
|-
| style="background:brown; color:white; height:12.75;"| Lenox–Park Avs
| style="background:brown; color:white; border-left:1px solid white;" | Soft Ground Tunnels
| style="background:brown; color:white; border-left:1px solid white;" |
| style="background:yellow; border-left:9px solid white;" | 64–58
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|-
| style="background:#f90; height:12.75;"| Park–3 Avs
| style="background:#f90; border-left:1px solid white;" | Mined with Cut and Cover
| style="background:#f90; border-left:1px solid white;" | 125 St Station
| style="background:#9cf; border-left:9px solid white;" | 58–56
| style="background:#9cf; border-left:1px solid white;" | Cut and Cover
| style="background:#9cf; border-left:1px solid white;" | 55 St Station
|-
| style="background:#ff0; height:12.75;"| 3 Av–120 St
| style="background:#ff0; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:#ff0; border-left:1px solid white;" |
| style="background:yellow; border-left:9px solid white;" | 56–43
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|-
| style="background:silver; height:12.75;"| 120–118
| style="background:silver; border-left:1px solid white;" | Rebuilt, existing
| style="background:silver; border-left:1px solid white;" | Bellmouth / TBM Launch ↑
| style="background:#f90; border-left:9px solid white;" | 43–41
| style="background:#f90; border-left:1px solid white;" | Mined with Cut and Cover
| style="background:#f90; border-left:1px solid white;" | 42 St Station
|-
| style="background:silver; height:12.75;"| 118–115
| style="background:silver; border-left:1px solid white;" | Rebuilt, existing
| style="background:silver; border-left:1px solid white;" | 116 St Station
| style="background:yellow; border-left:9px solid white;" | 41–34
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |

|-
| style="background:silver; height:12.75;"| 115–109
| style="background:silver; border-left:1px solid white;" | Existing
| style="background:silver; border-left:1px solid white;" |
| style="background:#9cf; border-left:9px solid white;" | 34–32
| style="background:#9cf; border-left:1px solid white;" | Cut and Cover
| style="background:#9cf; border-left:1px solid white;" | 34 St Station
|-
| style="background:#9cf; height:12.75;"| 109–105
| style="background:#9cf; border-left:1px solid white;" | Cut and Cover
| style="background:#9cf; border-left:1px solid white;" | 106 St Station
| style="background:yellow; border-left:9px solid white;" | 32–24
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|-
| style="background:silver; height:12.75;" | 105–99
| style="background:silver; border-left:1px solid white;" | Existing
| style="background:silver; border-left:1px solid white;" |
| style="background:#f90; border-left:9px solid white;" | 24–22
| style="background:#f90; border-left:1px solid white;" | Mined with Cut and Cover
| style="background:#f90; border-left:1px solid white;" | 23 St Station
|-
| style="background:#9cf; height:12.75;" | 99–92
| style="background:#9cf; border-left:1px solid white;" | Cut and Cover
| style="background:#9cf; border-left:1px solid white;" | 96 St Station / TBM Launch ↓
| style="background:yellow; border-left:9px solid white;" | 22–15
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|-
| style="background:yellow; height:12.75;" | 92–86
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
| style="background:#9cf; border-left:9px solid white;" | 15–11
| style="background:#9cf; border-left:1px solid white;" | Cut and Cover
| style="background:#9cf; border-left:1px solid white;" | 14 St Station
|-
| style="background:#f90; height:12.75;" | 86–83
| style="background:#f90; border-left:1px solid white;" | Mined with Cut and Cover
| style="background:#f90; border-left:1px solid white;" | 86 Street Station
| style="background:crimson; color:white; border-left:9px solid white;" | 11–Hanover
| style="background:crimson; color:white; border-left:1px solid white;" | Undecided
| style="background:crimson; color:white; border-left:1px solid white;" |
|-
| style="background:yellow; height:12.75;" | 83–72
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|-
| style="background:#f90; height:12.75;" | 72–69
| style="background:#f90; border-left:1px solid white;" | Mined with Cut and Cover
| style="background:#f90; border-left:1px solid white;" | 72 Street Station
|-
| style="background:yellow; height:12.75;" | 69–63
| style="background:yellow; border-left:1px solid white;" | Tunnel Boring Machine
| style="background:yellow; border-left:1px solid white;" |
|}

==== Phase 1 ====
[[File:SAS64thStreet201201.jpg|thumb|Tunnel at 64th Street]]Phase 1 of the Second Avenue Subway was constructed between the [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street]] station on the [[63rd Street Lines]] and an existing tunnel segment between 99th Street and 105th Street, with a terminal station at 96th Street. In Phase 1, tunneling was completed between East 63rd Street and East 92nd Streets through the use of TBMs. The TBM launch box was {{convert|814|by|75|feet|meters|adj=mid|-wide|sp=us}}, and is now part of the 96th Street station. Two access [[Shaft (civil engineering)|shafts]] were constructed for the 72nd Street station. [[Slurry wall|Slurry]] or [[diaphragm wall]]s, {{convert|1.1|m|ft|sp=us}} wide and {{convert|6.1|m|ft|sp=us}} long and about {{convert|35|m|ft|sp=us}} deep, were built alongside the sections between East 93rd and 95th Streets.<ref name="autogenerated1" />

Since the rock is shallower between East 91st and 93rd Streets, {{convert|1.1|m|ft|adj=mid|-diameter|sp=us}} [[Secant piled wall|secant piles]] did the same work at shallower depths.<ref name="autogenerated1" /> Earth excavation was conducted between walls once they were installed, and box structures were built using a bottom-up construction method. Temporary [[deck (building)|decking]] constituted the top of the boxes, and the decking both braced the excavation and supported the walls and Second Avenue traffic.<ref name="autogenerated1" />

[[File:2nd Av subway dig 83rd St jeh.JPG|thumb|Street-level work at 83rd Street]]The stations at 86th and 72nd Streets were mined. This was challenging, given the number of expensive [[high rise]] properties in their vicinities. The 96th Street cut-and-cover station was about {{convert|15|m|ft|sp=us}} deep, making it one of the shallowest stations being built on the line. The shallowness was so that the new line could align with the preexisting piece of subway tunnel built in the 1970s between 99th and 105th Streets.<ref name="autogenerated1" /> Stations at the two mined stations are between {{convert|25.9|and|27.4|m|ft|sp=us}} deep in rock.<ref name="sdeis3" /><ref name="ConstructionTechniques" /> The construction method that was used was supposed to ease concerns for buildings above the station sites, because only two shafts were required for excavation.<ref name="autogenerated1">{{cite magazine|url=http://www.nce.co.uk/fairytale-of-new-york-second-avenue-subway-takes-shape/1970428.article|title=Fairytale of New York&nbsp;– Second Avenue Subway takes shape|last=Wynne|first=Alexandra|date=January 20, 2009|magazine=New Civil Engineer|access-date=August 2, 2009|archive-date=May 15, 2009|archive-url=https://web.archive.org/web/20090515021205/http://www.nce.co.uk/fairytale-of-new-york-second-avenue-subway-takes-shape/1970428.article|url-status=dead}}</ref>

Of the below-ground obstacles, Arup director of construction David Caiden stated: "It's a spaghetti of tunnels, utilities, pipes and cables—I've never seen anything like it."<ref name="autogenerated1" /> Complicating the process, the project must go over, or under, subway lines, [[Amtrak]] railway lines, and the [[Queens-Midtown Tunnel]] linking Manhattan and Queens, in later phases.<ref name="autogenerated1" /> There were geological anomalies along the way of Phase 1. Manhattan's geology changes along the subway's length, passing through rock and soft ground, consisting of sands, [[silt]]s, and [[clay]]s over [[Manhattan schist]], and there are [[Fault (geology)|faults]] and [[shear zone]]s as well as [[fractured rock]].<ref name="autogenerated1" />

Hard-rock TBMs {{convert|6.7|m|ft|sp=us}} in diameter, {{Convert|450|ft|m}} in length, and {{Convert|485|ST|LT}} in weight were used to tunnel during the first phase, progressing at a rate of about {{convert|20|m|ft|sp=us}} per day.<ref name="autogenerated1" />

==== Phase 2 ====
Phase 2 will extend the line north from the [[96th Street (Second Avenue Subway)|96th Street]] station to the [[Harlem–125th Street (IND Second Avenue Line)|Harlem–125th Street]] subway station at Lexington Avenue. North of 120th Street, it will be constructed through the use of TBMs. The TBM Launch Box will be located between 118th Street and 120th Street on Second Avenue.<ref name="MTA-SEASCh2"/>{{rp|12}} The TBMs will head north under Second Avenue from 120th Street before turning slightly east to curve under the East River Houses, turning west on 125th Street, crossing Lexington Avenue, before ending either {{Convert|325|feet|meters}} east of Lenox Avenue or {{Convert|275|feet|meters}} to the west of Lenox Avenue to accommodate storage tracks. The tunnels near the 125th Street station would need to go through soft soil in addition to diving underneath the existing [[IRT Lexington Avenue Line]]. The soft-soil tunnels are in contrast to the hard-rock bored tunnels south of 92nd Street and the cut-and-cover tunnels north of that point (necessitated because Manhattan's rock profile drops sharply north of 92nd Street).<ref name="cb11-20160405" />{{rp|14}} The line is designed as to not preclude the construction of a station at Lenox Avenue and the extension of the line west along 125th Street.<ref name=":4" />{{Rp|25}}

South of 120th Street, the line will utilize a tunnel section built during the 1970s, located between 110th Street and 120th Street. This section will have tracks and other essential equipment installed, like that of the rest of the line. Cut-and-cover will be used to connect the existing tunnel section to the bored section to the north (at 120th Street) and to the portion of the line already in operation to the south (at 105th Street) to maximize the use of the tunnel sections built in the 1970s.<ref name="MTA-SASFEISCh3" />{{Rp|2}}<ref name=":52" />{{Rp|45}} A bellmouth will be constructed to allow for a future extension to the Bronx at 118th Street. The storage tracks west of the 125th Street station would replace the storage tracks north of the 96th Street station, which would then be used in revenue service as part of Phase 2.<ref name="MTA-SASFEISCh3" />{{Rp|48}}

[[File:MNRR 125 St 2 vc.jpg|thumb|right|alt=the elevated 125th Street station of the Metro-North Railroad|The Harlem–125th Street subway station, planned as part of phase 2, would contain an intermodal transfer to [[Metro-North Railroad|Metro-North]] trains at [[Harlem–125th Street (Metro-North station)|Harlem–125th Street]] (pictured).]]

A transfer will be constructed at the eastern end of the Second Avenue Subway's Harlem–125th Street station to connect to the [[IRT Lexington Avenue Line]]'s 125th Street station. A new lower-level mezzanine will house the connection between the two stations, directly connecting to the downtown platform for Lexington Avenue service. The direct connection to the staircases to the upper level will be rebuilt. At the western end of the station, staircases will lead to [[Park Avenue]], allowing passengers to walk to the [[Metro-North Railroad]]'s [[Harlem–125th Street station (Metro-North)|Harlem–125th Street station]].<ref name="MTA-SEASCh2" />{{Rp|23}}<ref name="MTA-SASFEISCh3" />{{Rp|58}}

The station entrances for 106th Street and 116th Street will be located on the east side of Second Avenue so as to avoid utilities located on the west side of the street and to avoid potential adverse effects to the East Harlem Historic District.<ref name=":4" />{{Rp|16}}

==== Phases 3 and 4 ====
Phases 3 and 4 will extend the line south from 63rd Street to Houston Street and Hanover Square, respectively. As part of Phase 3, a connection to the [[IND 63rd Street Line]] would be built, allowing for non-revenue moves into Queens. This connection will be constructed through underground drilling and blasting. Bellmouths already exist for this connection east of the [[Lexington Avenue–63rd Street (63rd Street Lines)|Lexington Avenue–63rd Street]] station. This section, like the rest of the line, will mainly consist of a two-track line. Between 21st Street and 9th Street, two additional tracks will be constructed on either side of the main alignment to allow for the storage of eight trains. This location was selected due to the sufficient depth of the area.<ref name="MTA-SASFEISCh3" />{{Rp|60}} The third phase would pass above several East River tunnels, including the 63rd Street Tunnel, the [[60th Street Tunnel]], the [[53rd Street Tunnel]], the [[Steinway Tunnel]] at 42nd Street, and the [[East River Tunnels]] at 32nd and 33rd Streets.<ref name=":21" />{{rp|5B·14}}

Like Phase 1, the sections between stations will largely be constructed through the use of [[Tunnel Boring Machine|TBM]]s, while stations will be constructed through cut-and-cover and mining, allowing for the construction of station caverns, shafts, and entrances. Five transfers are planned to connect stations on the Second Avenue Line and nearby stations on adjacent lines, increasing travel options for passengers. The transfer at [[Grand Street (IND Sixth Avenue Line)|Grand Street]] will require the construction of a mezzanine below the existing station, allowing for a vertical transfer to be constructed. The existing station will have to be rebuilt to accommodate the increased volume of passengers using the station. The Houston Street station's transfer to the [[Second Avenue (IND Sixth Avenue Line)|Second Avenue]] station of the [[IND Sixth Avenue Line]] would require some construction within the existing station.<ref name="MTA-SASFEISCh3" />{{Rp|55–60}}

The remaining three transfers are being proposed, and will be constructed, barring the increased cost of their construction. The transfer to the [[BMT Canarsie Line]]'s [[Third Avenue (BMT Canarsie Line)|Third Avenue]] station would consist of a passageway that will be {{Convert|200|feet|meters}} long. The most complicated of the transfers will be the connection between the 42nd Street station and the [[Grand Central–42nd Street (New York City Subway)|Grand Central]] station on the [[IRT Flushing Line]]. To allow for the connection to be built, a 900-foot long tunnel would be built under 42nd Street from the west side of Third Avenue to Second Avenue.<ref name="MTA-SASFEISCh3" />{{Rp|55–60}}

The Flushing Line station might have to be significantly reconstructed in anticipation of the increased volume of passengers and due to [[Americans with Disabilities Act of 1990|Americans with Disabilities Access]] requirements for the transfer. To allow for necessary vents and emergency exits to be built, cut-and-cover would be used. The final transfer would be between the 55th Street station and the [[Lexington Avenue–53rd Street (IND Queens Boulevard Line)|Lexington Avenue–53rd Street]] station on the [[IND Queens Boulevard Line]]. Either shielded mining or cut-and-cover would be used to complete the connection. The existing station would have to be modified to allow for the transfer passageway to be built.<ref name="MTA-SASFEISCh3" />{{Rp|55–60}}

[[File:East Midtown Plaza.jpg|thumb|alt=The East Midtown Plaza at 2nd Avenue and 23rd Street, where a Phase 3 subway station would be built|As part of Phase 3, a [[23rd Street (Second Avenue Subway)|station]] would be built at Second Avenue and [[23rd Street (Manhattan)|23rd Street]] (pictured).]]

Three construction options were evaluated during the project's Environmental Impact Study for the portion of the line between 11th Street and Hanover Square. One option known as the Shallow Chrystie Option would mainly use cut and cover, while the Deep Chrystie Street and Forsyth Options would use a combination of tunneling by [[Earth Pressure Balance Machine]]s (EPBMs) and cut and cover.<ref name="ConstructionTechniques" /> The Shallow Chrystie Option would have used the existing Confucius Plaza tunnel section between Canal and Division Streets. Like the plan from the 1970s, there would have been a cross-platform transfer to the existing Grand Street station, with the transfer expected to be heavily used.<ref name=":7" /><ref>{{cite web|url=http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Figure 2-6 Deep Chrystie Alignment|date=May 2004|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 7, 2016|archive-date=July 10, 2015|archive-url=https://web.archive.org/web/20150710093334/http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|url-status=live}}</ref>

This option would require digging up [[Sara Delano Roosevelt Park]] to the east as Chrystie Street is not wide enough to fit four tracks. Under this option, a track connection would be built to allow trains from Second Avenue to run via the [[Manhattan Bridge]] north tracks to allow service to Brooklyn. The Forsyth Option would curve below the park to Forsyth Street and the station would be built under Forsyth Street, requiring a 200-foot transfer passageway that would be less convenient than the other options.<ref name=":7" /><ref>{{cite web|url=http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Figure 2-6 Deep Chrystie Alignment|date=May 2004|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 7, 2016|archive-date=July 10, 2015|archive-url=https://web.archive.org/web/20150710093334/http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|url-status=live}}</ref>

The Deep Chrystie Option would have the Second Avenue Subway run deeper underground, running underneath the existing Grand Street station, with a mezzanine in between the two stations. In order to allow for sufficient room for stairways to transfer to the Second Avenue Line, the Grand Street station would be widened to have twenty foot wide platforms. No track connection would be built under this option, and the Confucius Plaza tunnel section would not be used for subway service, but it instead might be used for ancillary subway facilities. Currently, this is the preferred option.<ref name=":7" /><ref>{{cite web|url=http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|title=Second Avenue Subway Final Environmental Impact Statement (FEIS), May 2004 Figure 2-6 Deep Chrystie Alignment|date=May 2004|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 7, 2016|archive-date=July 10, 2015|archive-url=https://web.archive.org/web/20150710093334/http://web.mta.info/capital/sas_docs/feis/figure2-06.pdf|url-status=live}}</ref>

South of the terminal at Hanover Square, two tail tracks will be constructed through the use of a TBM to allow for the storage of four trains. The tracks would be built at a depth of about {{Convert|110|feet|meters}} under Water Street, allowing the line to be deep enough to tunnel under the [[East River]] for a possible future extension into Brooklyn. Cut-and-cover would be used to build a vent facility at a traffic island located at Water and Whitehall Streets.<ref name="MTA-SASFEISCh3" />{{Rp|50, 60}}<ref name="deis2" />{{Rp|2–11}}

=== Cost ===
There was controversy over the high cost of the line as a whole. The project was divided up into four phases, in part, to maximize the ability of the project to receive funding from the Federal Government as part of the Department of Transportation's New Starts Program. The initial projections for the cost of the line were made in the 2004 FEIS, with Phase 1 estimated to cost $3.8&nbsp;billion, Phase 2 estimated to cost $3.4&nbsp;billion, and Phases 3 and 4 each estimated to cost $4.8&nbsp;billion.<ref name="MTA-SASFEISCh3" />{{Rp|3}}

Phase 1 ended up costing $500&nbsp;million over its original budget of $3.8&nbsp;billion—still a very high price compared to other new subway systems worldwide.<ref name=":39">{{Cite web|url=http://www.thedailybeast.com/articles/2016/12/31/here-s-why-it-took-a-century-and-4-5-billion-to-add-just-three-subway-stops-in-new-york-city.html|title=Here's Why It Took A Century and $4.5 Billion To Add Just Three Subway Stops In New York City|last=Gelinas|first=Nicole|date=December 31, 2016|website=The Daily Beast|access-date=December 31, 2016|archive-date=January 1, 2017|archive-url=https://web.archive.org/web/20170101002525/http://www.thedailybeast.com/articles/2016/12/31/here-s-why-it-took-a-century-and-4-5-billion-to-add-just-three-subway-stops-in-new-york-city.html|url-status=live}}</ref> Regulations set by the [[Buy America Act]] forced the MTA to purchase materials made in the United States,<ref name=":39" /> which led to objections when an MTA contractor bought a [[fire suppression system]] made in Finland.<ref name=":39" /><ref>{{Cite news|url=https://www.transit.dot.gov/regulations-and-guidance/buy-america/second-avenue-subway-projects-water-mist-fire-suppression|title=Second Avenue Subway Project's Water Mist Fire Suppression System|last=Nifosi|first=Dana C.|date=October 9, 2015|publisher=[[Federal Transit Administration]]|access-date=December 31, 2016|archive-date=December 31, 2016|archive-url=https://web.archive.org/web/20161231171206/https://www.transit.dot.gov/regulations-and-guidance/buy-america/second-avenue-subway-projects-water-mist-fire-suppression|url-status=live}}</ref> Finally, the private and public sector could not cooperate smoothly on the project, further raising costs.<ref name=":39" /> Of the $4.5&nbsp;billion cost for Phase 1, $2.4&nbsp;billion was allocated to building the three new stations and renovating the Lexington Avenue–63rd Street station.<ref name=":40">{{Cite web|url=http://therealdeal.com/2016/12/31/new-yorks-incredibly-expensive-new-subway-explains-why-we-cant-have-nice-things-opinion/|title=New York's incredibly expensive new subway explains why we can't have nice things: Opinion|date=December 31, 2016|website=The Real Deal New York|access-date=December 31, 2016|archive-date=January 1, 2017|archive-url=https://web.archive.org/web/20170101002048/http://therealdeal.com/2016/12/31/new-yorks-incredibly-expensive-new-subway-explains-why-we-cant-have-nice-things-opinion/|url-status=live}}</ref> Meanwhile, $500&nbsp;million was spent on design and engineering, and another $734&nbsp;million was for building tunnels between the stations, tracks, signals, and trackside systems.<ref name=":40" />

The rest of the cost, $800&nbsp;million, was spent on "construction management, real estate, station artwork, fare-collection systems and other sundry items."<ref name=":40" /> The stations' cost was magnified by the depth of the stations and the enormity of the caverns that needed to be excavated. The Second Avenue Subway stations have full-length mezzanines, like the original IND but unlike other [[Deep level underground|deep-level]] projects such as [[London]]'s [[Elizabeth line]].<ref name=":40" /> The stations will have full-length mezzanines as opposed to smaller mezzanines for each entrance to accommodate anticipated ridership for the full-length line and to comply with emergency egress requirements.<ref name=":4" />{{Rp|13}}

In December 2016, after it was announced that Phase 2 might cost $6&nbsp;billion, transit experts expressed concern that the Second Avenue Subway might be so excessively costly as to preclude construction of Phases 3 and 4, as well as future expansions. One expert stated that the Phase 1 project was the most expensive subway project in the world, and that compared to other subway systems around the world, the cost of building new subways in New York City was much higher.<ref name=":29">{{Cite news|url=http://www.amny.com/transit/second-avenue-subway-cost-concerns-transit-experts-1.12792664|title=Experts concerned by Second Ave. subway's costly Phase II|last=Barone|first=Vincent|date=December 22, 2016|newspaper=am New York|access-date=December 23, 2016|archive-date=December 23, 2016|archive-url=https://web.archive.org/web/20161223104958/http://www.amny.com/transit/second-avenue-subway-cost-concerns-transit-experts-1.12792664|url-status=live}}</ref> The Second Avenue Subway's per-mile construction cost is higher than that of other projects in similar cities like London's Crossrail and [[Paris]]'s [[Grand Paris Express]], which themselves are among the most expensive underground-railway projects in the world.<ref name=":29" /> MTA officials stated that the Second Avenue Subway cost as much as it did only because of the complex underground infrastructure in Manhattan, as well as the fact that the New York City Subway operates [[24/7 service]].<ref name=":29" />

===Artwork===
For Phase 1 of the Second Avenue Subway, four contemporary artists were chosen to design artwork for the 96th, 86th, 72nd, and 63rd Street stations. The project consisted of four permanent installations: ''Blueprint for a Landscape'' by [[Sarah Sze]] at 96th Street; ''Subway Portraits'' by [[Chuck Close]] at 86th Street; ''Perfect Strangers'' by [[Vik Muniz]] at 72nd Street; and ''Elevated'' by [[Jean Shin]] at 63rd Street. These public artworks were sponsored and commissioned as part of the [[MTA Arts & Design]] program.<ref>{{Cite news |last=Kennedy |first=Randy |date=2016-12-19 |title=Art Underground: A First Look at the Second Avenue Subway |language=en-US |work=The New York Times |url=https://www.nytimes.com/2016/12/19/arts/design/second-avenue-subway-art.html |access-date=2022-05-19 |issn=0362-4331 |archive-date=January 9, 2017 |archive-url=https://web.archive.org/web/20170109203314/http://www.nytimes.com/2016/12/19/arts/design/second-avenue-subway-art.html |url-status=live }}</ref>

== Service patterns ==

=== Routes ===
[[File:NYCS-bull-trans-Q-Std.svg|75px|right|link=Q (New York City Subway service)]]
[[File:NYCS-bull-trans-N-Std.svg|75px|right|link=N (New York City Subway service)]]
[[File:NYCS-bull-trans-R-Std.svg|75px|right|link=R (New York City Subway service)]]

The opening of Phase 1 extended Q service to 96th Street from its former terminal at 57th Street.<ref name="NY1W" /> The Q service has a rush-hour service frequency of 7 to 10 trains per hour.<ref name="Q Timetable" /> By contrast, the IRT Lexington Avenue Line's express tracks ({{NYCS trains|Lexington express}}) have an estimated rush-hour frequency of 30 trains per hour, or one train approximately every 2 minutes in each direction.<ref>{{Cite news|url=http://www.nydailynews.com/new-york/longer-waiting-time-expected-ave-subway-line-article-1.2650118|title=Longer waiting time expected for Second Ave. subway line|last=Rivoli|first=Dan|date=May 25, 2016|newspaper=New York Daily News|access-date=December 14, 2016|archive-date=October 22, 2016|archive-url=https://web.archive.org/web/20161022074143/http://www.nydailynews.com/new-york/longer-waiting-time-expected-ave-subway-line-article-1.2650118|url-status=live}}</ref> As part of the 2004 Final Environmental Impact Study (FEIS) for the line, the Q service was planned to have a frequency of 14 trains per hour during rush hours,<ref name="Q Timetable" /><ref name=":21" />{{rp|5B·20}} but this was revised due to MTA schedule changes.<ref name="program201608" />

A few rush hour N trains that formerly short-turned at 57th Street began to run to 96th Street in January 2017. The northbound trips are labeled as Q trains via the Sea Beach Line to reduce passenger confusion.<!--Internally, they are labeled as N. The rationale is that passengers on the Sea Beach Line will take any train to Manhattan and passengers in Manhattan will not be confused as to where the train was terminating because the train would be labeled Q. On the other hand, if they were labeled N, passengers would be confused in Manhattan, and would delay service at 57th Street.--><ref name="program201608" /><ref name="N Timetable" /> Starting in November 2017, one northbound R train has served the line during weekday mornings, boosting service.<ref name=serviceincrease /> From April 2019 to April 2020, weekend and evening [[M (New York City Subway service)|M]] service was also diverted on the Second Avenue Subway to accommodate extra passengers during the [[14th Street Tunnel shutdown]].<ref>{{cite web|url=https://new.mta.info/l-project/service-alternatives|title=Service During the L Project|date=April 26, 2019|website=MTA|access-date=April 27, 2019|archive-date=April 24, 2019|archive-url=https://web.archive.org/web/20190424014235/https://new.mta.info/l-project/service-alternatives|url-status=live}}</ref><ref>{{cite web|title=Service information for L, M, G, 7, M14 SBS and free transfers|url=https://new.mta.info/l-project/post-tunnel-work-service|access-date=April 26, 2020|date=April 26, 2020|archive-date=April 26, 2020|archive-url=https://web.archive.org/web/20200426180938/https://new.mta.info/l-project/post-tunnel-work-service|url-status=live}}</ref>

In Phase 2, all current services will be extended to 125th Street and Lexington Avenue.<ref name="fta pdf"/> As part of the 2004 FEIS, it was planned for the Q service to be increased to 19 trains per hour to accommodate the projected increase in ridership.<ref name=":21" />{{rp|5B·20}} In order to allow for the construction of Phase 3, bellmouths have been constructed at the turnoff to the BMT 63rd Street Line.<ref>{{Cite web|url=https://i1.wp.com/ltvsquad.com/wp-content/uploads/2016/12/IMG_8675.jpg?w=900|title=It contains a provision for the full length Second Ave. Subway|last=Anastasio|first=Joseph|website=ltvsquad.com|access-date=December 30, 2016|archive-date=July 27, 2018|archive-url=https://web.archive.org/web/20180727004411/https://i1.wp.com/ltvsquad.com/wp-content/uploads/2016/12/IMG_8675.jpg?w=900|url-status=live}}</ref>

=== Future full-length designation ===
[[File:NYCS-bull-trans-T-Std.svg|75px|right|link=T (New York City Subway service)]]

When the construction of Phase 3 is completed, a new T service will operate from Harlem–125th Street to Houston Street.<ref>{{cite magazine|last=Hirschman|first=David|date=July 21, 2008|title=The T Train: NYC Will Get Its First New Subway Line in 70 Years|url=https://www.wired.com/cars/futuretransport/magazine/16-08/st_atlas|magazine=Wired|issue=Aug '08|page=36|quote=The old (1960s) T service was also called the [[BMT West End Line|West End train]]. The reference was to Brooklyn. By contrast, the new T service will serve the East Side of Manhattan, and 'will unite the Upper and Lower East Sides.'|archive-url=https://web.archive.org/web/20080725041558/http://www.wired.com/cars/futuretransport/magazine/16-08/st_atlas|archive-date=July 25, 2008|access-date=April 8, 2014}}</ref><ref name="fta pdf"/> After Phase 4 opens, T service will run the full length of the line, from Harlem–125th Street to Hanover Square.<ref name="fta pdf">{{cite web|url=http://www.fta.dot.gov/documents/SAS_make_the_case.pdf|title=Making the Case|date=August 20, 2004|website=fta.dot.gov|publisher=Federal Transit Administration|access-date=April 10, 2014|url-status=dead|archive-url=https://web.archive.org/web/20130227003027/http://www.fta.dot.gov/documents/SAS_make_the_case.pdf|archive-date=February 27, 2013|page=1}}</ref><ref name=":21" />{{Rp|5B·29 to 5B·30}} T service is planned to operate at a frequency of 14 trains per hour during rush hours, with the combined frequency north of 72nd Street with Q service being 28 trains per hour. With the opening of Phase 3, the frequency of Q service is planned to be reduced from 19 to 14 trains per hour.<ref name=":21" />{{rp|5B·20}}

The MTA decided to designate the future service with the letter T, in part because:<ref name="nymag20061026">{{cite journal|last=Reeves|first=Hope|date=October 26, 2006|title=The Second Avenue Subway Is Brought to You by the Letter T|url=http://nymag.com/daily/intel/2006/10/take_my_ttrain_please.html|journal=New York Magazine|access-date=August 2, 2009|archive-date=December 9, 2008|archive-url=https://web.archive.org/web/20081209030303/http://nymag.com/daily/intel/2006/10/take_my_ttrain_please.html|url-status=live}}</ref>
* H is the [[Rockaway Park Shuttle]]'s internal route designator, which has occasionally been used publicly, most notably from 1986–93 and again in 2012–13 following [[Hurricane Sandy]].<ref name=nymag20061026/>
* The letters I and O are too easily confused with the numbers 1 and 0, respectively.<ref name=nymag20061026/><ref name="UnusedRoutes">{{cite web|url=http://www.amny.com/urbanite-1.812039/v-and-w-trains-join-a-long-list-of-routes-that-have-bowed-out-of-the-subways-1.2028944|title=V and W trains join a long list of routes that have bowed out of the subways – am New York|last=Haddon|first=Heather|date=June 20, 2010|website=amny.com|publisher=amNewYork|access-date=October 23, 2016|url-status=dead |archive-url=https://web.archive.org/web/20100620213331/http://www.amny.com/urbanite-1.812039/v-and-w-trains-join-a-long-list-of-routes-that-have-bowed-out-of-the-subways-1.2028944|archive-date=June 20, 2010}}</ref>
* The letter K was used until the late 1980s to denote services on the [[IND Eighth Avenue Line]], and earlier on the [[BMT Jamaica Line]], and thus is not preferred.
* The letters P, U and Y are more easily confused with common words.<ref name="UnusedRoutes" />
* The letter V was in use at the time (and until 2010) to denote services on the [[IND Sixth Avenue Line]] and [[IND Queens Boulevard Line]].

The T{{'}}s route emblem is colored {{NYCS const|color|T}} ([[hex triplet]] #00ADD0, which could also be considered [[robin's egg blue]] or [[teal]]) because the color had also been used for the [[JFK Express]] in the past. In 2011, turquoise was considered "the color of the year", and at the time of the color's selection in the 2000s, it was considered a very upscale color.<ref name="nyt20110822">{{cite news|url=https://www.nytimes.com/2011/08/22/nyregion/the-color-teal-is-chosen-for-t-train-signs.html|title=Train Line Far From Arrival Has a Color to Be Noticed|first=Christine|date=August 22, 2011|work=The New York Times|access-date=August 14, 2015|last=Haughney|archive-date=June 17, 2022|archive-url=https://web.archive.org/web/20220617071535/https://www.nytimes.com/2011/08/22/nyregion/the-color-teal-is-chosen-for-t-train-signs.html|url-status=live}}</ref>

== Station listing ==
Three stations are part of Phase 1,<ref name="fta pdf"/> which opened in January 2017.<ref name=":1">{{Cite news|url=https://www.nytimes.com/2017/01/01/nyregion/second-avenue-subway-opening-upper-east-side-manhattan.html|title=Opening of Second Avenue Subway: Updates|last1=Slotnik|first1=Daniel E.|date=January 1, 2017|last2=Wolfe|first2=Jonathan|newspaper=The New York Times|issn=0362-4331|last3=Fitzsimmons|first3=Emma G.|last4=Palmer|first4=Emily|last5=Remnick|first5=Noah|access-date=January 1, 2017|archive-date=December 24, 2021|archive-url=https://web.archive.org/web/20211224223147/https://www.nytimes.com/2017/01/01/nyregion/second-avenue-subway-opening-upper-east-side-manhattan.html|url-status=live}}</ref><ref name=":41">{{Cite news|url=http://www.nydailynews.com/new-york/new-yorkers-ride-ave-subway-making-history-article-1.2930822|title=New Yorkers take historic first ride on Second Ave. subway|last1=Rivoli|first1=Dan|date=January 1, 2017|last2=Sandoval|first2=Edgar|newspaper=New York Daily News|last3=Brown|first3=Stephen Rex|access-date=January 1, 2017|archive-date=April 15, 2021|archive-url=https://web.archive.org/web/20210415194911/https://www.nydailynews.com/new-york/new-yorkers-ride-ave-subway-making-history-article-1.2930822|url-status=live}}</ref><ref name=":42">{{Cite news|url=http://www.wnyc.org/story/see-new-years-eve-party-and-2nd-ave-subway|title=See Inside: The 2nd Avenue Subway Opens to All|last=Nessen|first=Stephen|date=January 1, 2017|newspaper=WNYC|access-date=January 1, 2017|archive-date=August 31, 2020|archive-url=https://web.archive.org/web/20200831013618/https://www.wnyc.org/story/see-new-years-eve-party-and-2nd-ave-subway/|url-status=live}}</ref> Three more are planned for Phase 2 (including one transfer to an existing line); six more in Phase 3 (including up to four transfers); and four more in Phase 4 (including one transfer).<ref name="fta pdf"/>

{{NYCS service legend
| alltimes         = show
| rushonly         = show
| allexceptnights  = show
| weekendsevenings = show
| nightsonly       = show
| weekdaysonly     = show
| closed           = show
}}

{| class="wikitable"
!Neighborhood<br />(approximate)
! {{Access icon}}
! Station<ref name="fta pdf"/>
! Location
! Phase<ref name="fta pdf"/>
! Services
! Opened
! Transfers & Notes<ref name="fta pdf"/>
|-
! colspan=8 style="background:silver;" | Provision for expansion crosstown along [[125th Street (Manhattan)|125th Street]]
|- style="background:silver;"
| rowspan=4 style="background:silver; | [[East Harlem]]
| {{Access icon}}
| {{anchor|125th Street|Harlem–125th Street}} {{stl|NYCS|Harlem–125th Street}}
| 125th Street & Lexington–Park Avenues
| 2
|
| 2027 (proposed)<ref name=fta20161227/>
| {{NYCS trains|Lexington|time=show}} via transfer at {{stl|NYCS|125th Street|Lexington}}{{refn|group=note|name=bold|Select in-system transfers that have been confirmed if the full-length line is constructed.<ref name=feis-figure-201/>}}<br />[[M60 (New York City bus)|M60 SBS]] (to [[LaGuardia Airport]])<br />[[Metro-North Railroad]] at [[Harlem–125th Street station|Harlem–125th Street]]<br />Northern [[terminal station|terminal]] for {{NYCS|Q}} train (Phase 2) and {{NYCS|T}} train (Phase 3)
|-
! colspan=7 style="background:silver;" | Provision for expansion to [[the Bronx]]
|- style="background:silver;"
| {{Access icon}}
| {{anchor|116th Street}} {{stl|NYCS|116th Street|Second}}
| 116th Street & 2nd Avenue
| 2
|
| 2027 (proposed)<ref name=fta20161227/>
| [[M15 (New York City bus)|M15 SBS]] (southbound only)<br />Would be located in unused tunnel between 115th to 120th Streets
|- style="background:silver;"
| {{Access icon}}
| {{anchor|106th Street}} {{stl|NYCS|106th Street|Second}}
| 106th Street & 2nd Avenue
| 2
|
| 2027 (proposed)<ref name=fta20161227/>
| [[M15 (New York City bus)|M15 SBS]] (southbound only)
|-
| rowspan=2 | [[Upper East Side]] ([[Yorkville, Manhattan|Yorkville]])
| {{Access icon}}
| {{anchor|96th Street}} {{stl|NYCS|96th Street|Second}}
| 94th–96th Streets & 2nd Avenue
| 1
| {{NYCS Second|time=show}}
| January 1, 2017<ref name=":1" /><ref name=":41" /><ref name=":42" />
| [[M15 (New York City bus)|M15 SBS]] (southbound only)<br />Northern [[terminal station|terminal]] for {{NYCS|Q}} trains (and limited {{NYCS|N}} and {{NYCS|R}} trains) in Phase 1
|-
| {{Access icon}}
| {{anchor|86th Street}} {{stl|NYCS|86th Street|Second}}
| 83rd–86th Streets & 2nd Avenue
| 1
| {{NYCS Second|time=show}}
| January 1, 2017<ref name=":1" /><ref name=":41" /><ref name=":42" />
| [[M15 (New York City bus)|M15 SBS]] (southbound only), [[M86 (New York City bus)|M86 SBS]]
|-
| rowspan=2 | [[Upper East Side]] ([[Lenox Hill]])
| {{Access icon}}
| {{anchor|72nd Street}} {{stl|NYCS|72nd Street|Second}}
| 69th–72nd Streets & 2nd Avenue
| 1
| {{NYCS Second|time=show}}
| January 1, 2017<ref name=":1" /><ref name=":41" /><ref name=":42" />
| [[M15 (New York City bus)|M15 SBS]] (southbound only)
|-
! colspan=7 | {{NYCS Second|time=show}} trains split to/from [[BMT Broadway Line]] via [[63rd Street Lines|BMT 63rd Street Line]] (Phase 1)
|- style="background:silver;"
| rowspan=2 | [[Midtown Manhattan|East Midtown]]
! colspan=7 | {{NYCS|T}} train continues down Second Avenue (Phase 3)
|- style="background:silver;"
| {{Access icon}}
| {{anchor|55th Street}} 55th Street
| 55th Street & 2nd Avenue
| 3
|
|
| {{NYCS trains|Lexington 51st|time=show}} via proposed transfer at [[Lexington Avenue/51st Street (New York City Subway)|Lexington Avenue/51st Street]]{{refn|group="note"|name="transfer"|Transfers are "under evaluation" and have not been confirmed yet.<ref name=feis-figure-201>{{cite web|url=http://web.mta.info/capital/sas_docs/feis/figure2-01.pdf|title=Figure 2-1: New York City Subway Service with Second Avenue Subway Line|website=mta.info|publisher=[[Metropolitan Transportation Authority]]|date=May 2004|access-date=December 15, 2016|archive-date=March 4, 2016|archive-url=https://web.archive.org/web/20160304003958/http://web.mta.info/capital/sas_docs/feis/figure2-01.pdf|url-status=live}}</ref>}}<br />[[M15 (New York City bus)|M15 SBS]] (southbound only)
|- style="background:silver;"
| [[Turtle Bay, Manhattan|Turtle Bay]]
| {{Access icon}}
| {{anchor|42nd Street}} 42nd Street
| 42nd Street & 2nd Avenue
| 3
|
|
| {{NYCS trains|Grand Central|time=show}} via proposed transfer at [[Grand Central–42nd Street (New York City Subway)|Grand Central–42nd Street]]{{refn|group="note"|name="transfer"}}<br />[[Metro-North Railroad]] at [[Grand Central Terminal]] <br />[[Long Island Rail Road]] at [[Grand Central Madison]]<br />[[M15 (New York City bus)|M15 SBS]] (southbound only)
|- style="background:silver;"
| [[Murray Hill, Manhattan|Murray Hill]]
| {{Access icon}}
| {{anchor|34th Street}} 34th Street
| 34th Street & 2nd Avenue
| 3
|
|
| [[M15 (New York City bus)|M15 SBS]] (southbound only), [[M34 (New York City bus)|M34 & M34A SBS]] to [[East River Ferry]]
|- style="background:silver;"
| [[Kips Bay, Manhattan|Kips Bay]]
| {{Access icon}}
| {{anchor|23rd Street}} 23rd Street
| 23rd Street & 2nd Avenue
| 3
|
|
| [[M15 (New York City bus)|M15 SBS]] (southbound only), [[M23 (New York City bus)|M23 SBS]]
|- style="background:silver;"
| rowspan=2 | [[East Village, Manhattan|East Village]]
| {{Access icon}}
| {{anchor|14th Street}} 14th Street
| 14th Street & 2nd Avenue
| 3
|
|
| {{NYCS trains|Canarsie|time=show}} via proposed transfer at [[Third Avenue (BMT Canarsie Line)|Third Avenue]]{{refn|group="note"|name="transfer"}}<br />[[M15 (New York City bus)|M15 SBS]] (southbound only)
|- style="background:silver;"
| {{Access icon}}
| {{anchor|Houston Street}} [[Houston Street (Second Avenue Subway)|Houston Street]]
| Houston–3rd Streets & 2nd Avenue
| 3
|
|
| {{NYCS trains|Sixth south|time=show}} via proposed transfer at [[Second Avenue (IND Sixth Avenue Line)|Second Avenue]]{{refn|group="note"|name="transfer"}}<br />[[M15 (New York City bus)|M15]] (southbound only)<br />Southern [[terminal station|terminal]] for {{NYCS|T}} train (Phase 3)
|- style="background:silver;"
| rowspan=2 | [[Chinatown, Manhattan|Chinatown]]
| {{Access icon}}
| {{anchor|Grand Street}} [[Grand Street (Second Avenue Subway)|Grand Street]]
| Grand & Chrystie Streets
| 4
|
|
| {{NYCS trains|Chrystie Manhattan|time=show}} via transfer at [[Grand Street (IND Sixth Avenue Line)|Grand Street]]{{refn|group=note|name=bold}}
|- style="background:silver;"
|| {{Access icon}}
|| {{anchor|Chatham Square}} Chatham Square
| East Broadway & Bowery
|| 4
|
|
|| at Worth Street
|- style="background:silver;"
| rowspan=2 | [[Financial District, Manhattan|Financial District]]
|| {{Access icon}}
|| {{anchor|Seaport}} Seaport
| Fulton & Water Streets
|| 4
|
|
|| [[M15 (New York City bus)|M15 SBS]] (at [[Fulton Street (Manhattan)|Fulton Street]])
|- style="background:silver;"
| {{Access icon}}
| {{anchor|Hanover Square}} Hanover Square
| William & Water Streets
| 4
|
|
| [[M15 (New York City bus)|M15 SBS]] (at Old Slip)<br />Southern [[terminal station|terminal]] for {{NYCS|T}} train (Phase 4)
|-
! colspan=8 style="background:silver;" | Provision for expansion to [[Brooklyn]]
|}

== See also ==
<!-- Please keep entries in alphabetical order & add a short description per [[WP:SEEALSO]]. -->
* [[Fulton Center]]
* [[Lower Manhattan–Jamaica/JFK Transportation Project]]
* [[Transportation in New York City]]
<!-- Please keep entries in alphabetical order. -->

== References ==
'''Informational notes'''
{{Reflist|group="note"}}

'''Citations'''
{{Reflist}}

'''Further reading'''
* {{cite book |last=Bessel |first=Richard |date=1968 |title=A history of the Second Avenue subway |publisher=New York City Transit Authority |oclc=5971204 }}
* {{cite report |first1=Eric |last1=Goldwyn |first2=Alon |last2=Levy |first3=Elif |last3=Ensari |date=February 11, 2023 |title=The New York Case Study |url=https://transitcosts.com/wp-content/uploads/NewYork_Case_Study.pdf |publisher=NYU Marron Institute |url-status=live |archive-url=https://web.archive.org/web/20230223115737/https://transitcosts.com/wp-content/uploads/NewYork_Case_Study.pdf |archive-date=2023-02-23}}
* {{cite web | author=MTA Capital Construction | title=Second Avenue Subway Supplemental Environmental Assessment |publisher=[[Metropolitan Transportation Authority]] | date=July 12, 2018 | url=http://web.mta.info/capital/sas_docs/ea_phase2.htm }}
* {{Cite book|last=Paterson|first=David A.|author-link=David Paterson|date=2020|title=[[Black, Blind, & In Charge: A Story of Visionary Leadership and Overcoming Adversity]]|publisher=Skyhorse Publishing|location=New York, New York|isbn=978-1-5107-5633-5}}
* {{cite book |last=Plotch |first=Philip |year=2020 |title=Last Subway: The Long Wait for the Next Train in New York City |location=Ithaca, New York |publisher=Three Hills, an imprint of Cornell University Press |isbn=978-0-8014-5366-3 |oclc=1099546659 }}

== External links ==
{{Attached KML|display=inline,title}}
{{external media
| headerimage = [[File:2 Av Subway Retrospective (8972227857).jpg|220px|link=|alt=]]
| topic       = YouTube video clips about the Second Avenue Subway by Metropolitan Transportation Authority
| width       = 220px
| float       = right
| video1      = [//www.youtube.com/watch?v=ejyEle360PE MTA Video Release – Second Avenue Subway], December 31, 2016; 7:13
| video2      = [//www.youtube.com/watch?v=fAziJqwjjoU Introducing the Second Avenue Subway], December 31, 2016; 11:31
}}
<!-- Please see http://en.wikipedia.org/wiki/WP:EL before adding links. -->
<!-- Wikipedia is WP:NOTNEWS, and should not list every news article on the subject. Please stop adding them every time NY1 puts out a story. -->
* {{Commons category-inline|IND Second Avenue Line}}
* [https://new.mta.info/project/second-avenue-subway-phase-2 Second Avenue Subway – Phase 2]
* {{webarchive |url=https://web.archive.org/web/20180206173426/http://web.mta.info/capital/sas_alt.html |title=Second Avenue Subway – Phase 1}}
* [https://www.flickr.com/photos/mtaphotos/collections/72157627663707214/ Official MTA Flickr webpage]
* [https://web.archive.org/web/20090529150142/http://www.transitmuseumeducation.org/fbu/projects/secondavenue Second Avenue Subway: A New York Transit Museum online exhibit]
* {{NYCS ref|http://www.nycsubway.org/wiki/The_Second_Avenue_Subway|The Second Avenue Subway|Overview}}
* [https://www.citylab.com/transportation/2016/12/mapping-the-history-of-the-second-ave-subway/511790/ New York's Second Ave Subway: A Century in Maps]
<!-- Please see http://en.wikipedia.org/wiki/WP:EL before adding new links. -->
<!-- Wikipedia is WP:NOTNEWS, and should not list every news article on the subject. Please stop adding them every time NY1 puts out a story. -->

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