Second Avenue Subway

Extent and service

Services that use the Second Avenue Line through Midtown Manhattan are to be colored turquoise. The following services use part or all of the Second Avenue Line:

Phase 1

Phase 1 of the Second Avenue Line, which opened at the start of 2017, is entirely in Manhattan. It runs from Second Avenue and 65th Street to Second Avenue and 105th Street. It is double-tracked along its entire length, with both tracks in parallel tubes bored by tunnel boring machines. Phase 1 stations are located at 72nd Street, 86th Street, and 96th Street. All of these stations use an island platform layout, with the platforms at each station located between the two tracks. Past 96th Street, both tracks continue as storage tracks until they end at 105th Street.

The Second Avenue Subway connects to the BMT Broadway Line, utilizing an existing connection via the 63rd Street Line as part of phase 1. The Q and N services operate northward from 57th Street–Seventh Avenue, curving east under Central Park on the 63rd Street Line. The Q and N trains then stop at Lexington Avenue–63rd Street with a cross-platform interchange to the F train before merging with the Second Avenue Line at 65th Street. This connection is also double-tracked. The northbound 63rd Street Connector track dips below the level of where Phase 3's tunnels will be located, providing for a future flying junction between the connector and the Second Avenue Line.

Plans for expansion

The long-term plans for the Second Avenue Subway involve digging 8.5 miles (13.7 km) of new tunnels north to 125th Street in Harlem and south to Hanover Square, which is located in the Financial District of Lower Manhattan. The other three phases would also be double-tracked. The area between 21st and 9th Streets (including the 14th Street station) is to be tentatively four-tracked, with the outer two tracks used for train storage. Thus, after Phase 4 is completed, the residents of Spanish Harlem and the Upper East Side will have direct mass transit service down both Second Avenue and Broadway (via transfer) to the Financial District, and across the Manhattan Bridge to Brooklyn via the Q train (as well as via the few rush-hour N trains).

An additional two-track connection is planned between the line toward Lower Manhattan (around 63rd Street) and the IND 63rd Street Line toward Queens using existing bellmouths that are at 63rd Street and First Avenue. Current plans do not call for it to be used by regular service, but instead to be used for non-revenue moves and to provide a connection to the Jamaica subway yard. The connection would allow for trains to run from the Financial District to Queens if the capacity of the IND Queens Boulevard Line was increased, or if the Queens Bypass was built. Service from Queens via the 63rd Street Tunnel would allow for the full capacity of the line south of 63rd Street to be used. Plans include provisions for an extension north under Second Avenue past 125th Street to the Bronx, and an extension south to Brooklyn.

Initial attempts

From 1919 through the 1980s, several different entities came up with many distinct plans for the Second Avenue subway line that were never carried out. The complex reasons for these delays are why the line is sometimes called "The Line That Time Forgot".

1919–1941: Initial planning

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. 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. Massively scaled-down versions of some of Turner's plans were found in proposals for the new city-owned Independent Subway System (IND). 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. Turner also proposed that the two elevated lines be knocked down to make room for the 6-track Second Avenue Subway. The plan was to connect the new line to the then-unbuilt Sixth Avenue and Eighth Avenue subway lines.

In January 1927, Turner submitted a revised proposal. It was now going to connect to a Tenth Avenue trunk line as well as to crosstown lines in the Bronx and Queens. The Second Avenue Subway was still a six-track line through Manhattan, except for a short eight-track tunnel at its junction with the Queens lines. The plan called for a connection to the IND Concourse Line in the Bronx, as well as another one to the IND Fulton Street Line in Brooklyn. Such a plan would have cost $165,000,000 (equivalent to $2,275,000,000 in 2016), including connections and underwater crossings. As the IRT Lexington Avenue Line got more crowded, some suggested ideas that were considered unusual. One suggestion included a new tunnel under Lexington Avenue, while another included a tunnel under a separate right-of-way between Second and Third Avenue.

On September 15, 1929, the Board of Transportation of the City of New York (BOT) tentatively approved the expansion, which included a Second Avenue Line with a projected construction cost of $98,900,000 (equivalent to $1,367,000,000 in 2016), not counting land acquisition. From north to south, the 1929 plan included four tracks from the Harlem River (where it would continue north as a Bronx trunk line with several branches) to 125th Street, six tracks from 125th Street to a link with the Sixth Avenue Line at 61st Street, four tracks from 61st Street to Chambers Street, and two tracks from Chambers Street to Pine Street. The plan was soon modified with the addition of another Bronx branch, as well as an extension of the subway to Water and Wall Streets. At the time, it was supposed to be completed between 1938 and 1941. In anticipation of the line's opening, real estate prices along the proposed route rose by an average of 50%; there were high demand for tenements along the route of the proposed subway; and sites located at street corners along the route were quickly bought up.

Due to the Great Depression, the soaring costs of the expansion became unmanageable. Construction on the first phase of the IND was already behind schedule, and the city and state were no longer able to provide funding. By 1930, the line was shortened to between 125th and 34th Streets, with a turnoff at 34th Street and a crosstown connection there; this line was to be complete by 1948. The line above 32nd Street was to start construction in 1931, with construction of a southern extension to Houston Street to commence in 1935; these segments would open in 1937 and 1940, respectively. This scaled-down plan was postponed in 1931. By 1932, the Board of Transportation had come up with another plan, which omitted a branch in the Bronx in order to cut costs. The new line's southern terminus would be truncated to the Nassau Street Loop.

Further revision of the plan and more studies followed. By 1939, construction had been postponed indefinitely, and Second Avenue line was relegated to "proposed" status, and was number 14 on the Board of Transportation's list of important transportation projects. The Second Avenue line was also cut to two tracks, but now had a connection to the BMT Broadway Line. The reduced plan now had a single northern branch through Throggs Neck, Bronx, and a branch south into Brooklyn, connecting to a stub of the IND Fulton Street Line at the Court Street station, which is now the site of the New York Transit Museum. The subway was now also US$249 million (equivalent to $4,054,000,000 in 2016). 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.

1940s–1950s: After World War II

As part of 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, continuing the IND's trend of phasing out elevated lines and streetcars in favor of new subways. For example, the IND Sixth Avenue Line replaced the Sixth Avenue Elevated, while the IND Fulton Street Line replaced the Fulton Street Elevated. Demolition of the elevateds also had the perceived effect of revitalizing the neighborhoods. The northern half of the Second Avenue Elevated, serving the Upper East Side and East Harlem closed in 1940; the southern half, running through Lower Manhattan, East Midtown and across the Queensborough Bridge to Queens, closed on June 13, 1942. The demolition of the Second Avenue elevated caused overcrowding on the Astoria and Flushing Lines in Queens, which no longer had direct service along Manhattan's far East Side. Because of the elevated line's closure, as well as a corresponding increase in the East Side population, the need for a Second Avenue subway increased.

In 1944, Mayor Fiorello H. La Guardia announced that work on the Second Avenue subway line was progressing. The same year, BOT superintendent Philip E. Pheifer came up with a map of train frequencies for the line, with about 56 trains per hour projected to go through the Second Avenue line. Pheifer also put forth a proposal for Second Avenue Subway services, which would branch extensively off to B Division lines, including the IND Sixth Avenue Line, BMT Broadway Line, and BMT Nassau Street Line, via pre-existing BMT trackage over the Manhattan and Williamsburg Bridges. From Canal Street to 57th Street the line was to be four tracks, with six tracks north of 57th Street. South of Canal Street there would be two tracks. The subway was to be opened by 1951. In addition, a new Bronx Branch would replace the Third Avenue El in the Bronx. By 1945, though, plans for the Second Avenue Subway were again revised. The southern two-track portion was abandoned as a possible future plan for connecting the line to Brooklyn, while a Bronx route to Throggs Neck was put forth.

Under Mayor William O'Dwyer and General Charles P. Gross, 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. This plan would again connect the Second Avenue Line to Brooklyn. As with Pheifer's proposal, a train frequency map was created; however, Bingham's proposal involved more branch lines and track connections. A connection to Brooklyn was to be made via the Manhattan and Williamsburg Bridge, and would allow trains from these bridges to go onto the Sixth Avenue Line or the Second Avenue Line. Other connections to the Second Avenue Line were to be provided at 57th Street, via a line connecting to the Sixth Avenue Line; two express tracks would be built along that line north of West Fourth Street. The IRT Pelham Line would be switched to the combined IND/BMT division (this plan also includes other connections, which have been built), and connected to the Second Avenue Line. The Second Avenue Line would end just north of that connection, at 149th Street, with transfers to the IRT White Plains Road Line and the elevated IRT Third Avenue Line, the latter of which would be demolished south of 149th Street. There would also be a connection to the IND Concourse Line. The line was to be built in sections. The Manhattan section was top-priority, but the Brooklyn section was 19th on the priority list, and the Bronx section did not have a specific priority.

By the next year, New York City had budget shortfalls. The City was short of $145 million (in 1948 dollars) that were needed for rehabilitation and proposed capital improvements, which cost a total of $800 million. The City petitioned the New York State Legislature to exceed its $655 million debt ceiling so that the city could spend $500 million on subway construction, but this request was denied.

The New York Board of Transportation 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 $1,000,000 in 2016) each; the train became known as the "million dollar train". 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 filters and ultraviolet lamps in their ventilation systems to kill germs.

By 1949, Queens and Lower Manhattan residents complained that the Second Avenue Subway would not create better transit options for them. A year later, revised plans called for a connection from Second Avenue at 76th Street to Queens, under 34th Avenue and Northern Boulevard, via a new tunnel under the East River. Connections would also be made to the Long Island Rail Road (LIRR)'s Rockaway Beach Branch. 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. 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. Out of a half-billion-dollar bond measure, only $112 million (equivalent to $1,033,000,000 in 2016), or 22% of the original amount, went toward the Second Avenue Subway. By then, construction was due to start by either 1952 or 1957, with estimated completion by 1958 at the earliest. Because many people thought that the bonds were solely to be used on the new subway, many people accused the New York City Transit Authority (NYCTA) of misusing the bonds.

A block to the west of the proposed subway line, the Manhattan section of the Third Avenue Elevated, the only other elevated line in the area, closed on May 13, 1955, and was demolished in 1956. Contrary to what many East Side residents thought, the demolition of the elevateds did not help the travel situation, as the Lexington Avenue Line was now the only subway transportation option on the East Side.

By 1957, it had been made clear that the 1951 bond issue was not going to be able to pay for the Second Avenue Line. The money had been used for other projects, such as the integration of the IRT Dyre Avenue Line, and IND Rockaway Line and reconfiguration of the DeKalb Avenue Interlocking. By then, the New York Times despaired of the line's ever being built. "It certainly will cost more than $500,000,000 and will require a new bond issue," wrote one reporter. In March of that year, NYCTA chairman Charles L. Patterson stated that the NYCTA had used the bond funds properly and that the bonds were not dedicated solely to fund the Second Avenue Line. He stated that the bonds had been allocated to the corridor based on increasing ridership on the Second Avenue Line, but admitted that currency inflation, as well as necessary rehabilitation work to the existing lines, made the Second Avenue Line unlikely in the near future.

1960s: New plans

As the early 1960s progressed, the East Side experienced an increase in development, and the Lexington Avenue Line became overcrowded. 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 station on the Sixth Avenue Line (another station, 57th Street, opened in July 1968), and introduced the most significant service changes ever carried out in the subway's history. 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. Although the connection only served Sixth Avenue Line trains, it was essentially the first part of the Second Avenue line constructed.

Plans approved

In 1964, Congress passed the Urban Mass Transportation Act, promising federal money to fund mass transit projects in America's cities via the Urban Mass Transportation Administration (UMTA). Three years later, voters approved a $2.5 billion (worth about $17,957,000,000 in current dollars) Transportation Bond Issue, which provided over $600 million (worth $4,310,000,000 today) for New York City projects, including for a 1968 Program for Action. The Second Avenue project, for a line from 34th Street to the Bronx, was given top priority. The City secured a $25 million UMTA grant for initial construction. On March 19, 1970, the Board of Estimate approved Route 132-C, which was the portion of the line south of 34th Street. Mayor John Lindsay, on August 16, 1970, announced the approval of a $11.6 million design contract for the line, which was awarded to DeLeuw, Cather & Company. Second Avenue was chosen for a subway line over First Avenue because it was closer to places of employment than First Avenue.

The Program for Action proposed a Second Avenue line to be built in two phases: The first phase, officially Route 132-A, would start from 34th Street in Midtown, running up Second Avenue to 126th Street and continuing to the Bronx, with stops planned at Kips Bay (34th Street), United Nations (between 44th Street and 48th Street), Midtown East (57th Street), Yorkville (86th Street), Franklin Plaza (106th Street), and Triboro Plaza (125th Street). The 48th Street stop would connect to a planned Metropolitan Transportation Center at Third Avenue and 48th Street, which would contain a new east side terminal for the Long Island Rail Road. The line included older proposals for connections to the Sixth Avenue and Broadway lines in Midtown via a new crosstown line, which would now be located on 63rd Street. The BMT 63rd Street Line would also include a connection allowing Second Avenue line trains to run to Queens. Between 72nd Street and 48th Street there were going to be four tracks.

The entirety of the 4.7 mile-long Route 132-A was to be constructed underground through tunneling and cut-and-cover. Station mezzanines; the line north of 92nd Street, where the rock profile drops away sharply; and the area around 48th Street, where there is a crevice in the rock profile, would be constructed using cut-and-cover. The temporary decking of Second Avenue was required for this construction to take place and to allow for traffic aboveground to proceed. The remaining portions of the line were to be built through tunneling. Only one business relocation was planned for the construction of the line. A gas station at the southeast corner of 63rd Street and Second Avenue was to be relocated as the site needed to be used for a construction and ventilation shaft, in addition to being used for a permanent ventilation superstructure. Underground easements were to be required under 13 properties in the vicinity of 63rd Street. Compared to other subway lines, the Second Avenue line was going to be much quieter.

In the Bronx, the line would run along East 138th Street, with a cross-platform transfer to Lexington Avenue Line trains at Brook Avenue on the IRT Pelham Line, which would be reconfigured. After that, Second Avenue line trains would use a new express bypass line along East 138th Street, and the former tracks of the New York, Westchester and Boston Railway (NY&WB) near the Bruckner Expressway. In Hunts Point, service would split into two branches. One branch would continue to use former NY&WB trackage to East 180th Street, at which point the line would connect to the IRT Dyre Avenue Line. A second branch would connect to the IRT Pelham Line in the vicinity of Whitlock Avenue station, another element from earlier plans. The first branch would take over all service on the Dyre Avenue Line, offering cross-platform transfers to IRT White Plains Road Line trains at East 180th Street station, which would also be reconfigured. The second branch would take over service on the upper portion of the Pelham Line, between Whitlock Avenue and Pelham Bay Park. All stations on the Dyre Avenue and upper Pelham Lines would have platforms shaved back to accommodate larger B Division trains. There were 140,000 daily passengers expected on the Second Avenue line at 64th Street, reducing the number of passengers on the Lexington Avenue Line from 287,000 passengers at 64th Street to 171,000.

The second phase of construction would extend the Second Avenue line south from 34th Street in Midtown to Lower Manhattan, with stations at 23rd Street, 14th Street, East Houston Street, Grand Street, Chatham Square, Pine/Wall Streets, and a terminal at Whitehall Street. The alignment for this portion of the line would have been via Second Avenue, Chrystie Street, Chatham Square, Saint James Place, and Water Street. Free transfers would be offered to existing lines at 14th Street, East Houston Street and Whitehall Street, while Grand Street would be reconstructed. Pine-Wall and Whitehall Street stations would both have four tracks (two platform levels with two tracks each) in order to increase the capacity of the Whitehall Street terminal above 30 trains per hour, and to improve passenger flow. Also during this phase, service on the upper Pelham Line would be extended to Co-op City, Bronx. A third branch of the Second Avenue line to replace the Third Avenue El in the Bronx would also be built, running adjacent to the right-of-way of Metro-North’s Harlem Line on Park Avenue. Construction of the entire line was seen as conducive to revitalizing New York City's then-declining economy, and the line was a big component of the 1969 "Plan for New York City" proposal.

Station location controversy

The line's planned stops in Manhattan, spaced farther apart than those on existing subway lines, proved controversial; 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 silk stocking route.” In order to cut down on walking distance, the stations would have been up to four blocks long. The plan for stations was reluctantly disclosed by the NYCTA on August 27, 1970 after a meeting with Assemblyman Stephen Hansen, who represented an area that covered the Upper East Side. Justifying the lack of stations, the NYCTA's chief engineer John O'Neil said that a station on the line cost $8 million which made it prohibitively expensive to build more. The stations at 34th Street and 125th Street were decided as they would be the terminal points, and the 48th Street location was decided because of a transfer to a proposed people mover that would take riders to other subway lines and the West Side. 57th Street was decided because of the large volume of crosstown traffic, and 86th Street had been decided upon because of the large number of high-rise buildings and stores in the area. These two stations and 106th Street were decided upon in a planning report.

People protested for almost a year over the lack of stations at 72nd and 96th Streets. On August 27, 1971, a new plan for the line was unveiled with a Lenox Hill (72nd Street) station and an extension of the 48th Street station southward almost to 42nd Street. The 96th Street station was still not in the official plans, despite the proximity of the Metropolitan Hospital Center to the proposed station. In response to public outcry, the MTA announced the addition of a station at 96th Street in 1971. The 96th Street station was added to the project at the cost of $10 million. In the 1971 plan, several stations were stretched to give riders the impression that they were already in the station, while they would have to walk long distances in underground passages to reach the trains. The line’s planned route on Second Avenue, Chrystie Street and the Bowery in the Lower East Side also drew criticism from citizens and officials. In January 1970, 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.

The subway soon became a political bargaining chip. Elected officials from Manhattan Community Board 8 protested the lack of stations in East Harlem. When politicians from the Lower East Side started advocating for the $55 million (worth about $325,000,000 in current dollars) Avenue C cuphandle, which would have served nearly 50,000 people, Queens politicians stated that the money would be better used to reactivate the abandoned Rockaway Beach Branch, which would cost only $45 million (equal to about $266,000,000 today) and would serve over 300,000 people. On March 19, 1970, the Board of Estimate approved the connecting loop through the Lower East Side. The route was a compromise; a year earlier the board vetoed the Second Avenue Line proposal, and instead proposed that the main line go eastward from East 17th Street onto Avenue A and then curve onto the regular route at Chatham Square. The NYCTA said that it would cost $55 million more than a direct line and the transfer at Grand Street would have been lost. In addition, less riders would have been diverted from the Lexington Avenue Line under this scheme. Two services were planned to use the loop. Some trains from the IND Sixth Avenue Line would join the loop at Houston Street and Second Avenue and then swing around to 14th Street and Eighth Avenue. There would also have been a shuttle between those two stations.

By 1971, officials had still not confirmed any of the line's stations. The MTA was planning to only add 13 stops along the line in Manhattan, with six of these above 34th Street; by comparison, the parallel Lexington Avenue Line had 23 stops in Manhattan, of which 12 were above 33rd Street. The reasoning behind this was to give faster service to riders from the Bronx and Queens, from where trains would funnel into either the new Second Avenue mainline or the existing Sixth Avenue and Broadway Lines. Disagreements over the number and location of stations were still ongoing, with New York Magazine advising readers to "get community support" if they wanted a station to be built in their vicinity. The dispute over the Second Avenue Subway applied between several disparate groups. Those arguing included residents of the Bronx and Queens who had poor infrastructure compared to residents of Manhattan and Brooklyn; the generally affluent residents of the Upper East Side; the ethnically diverse communities of lower Manhattan and East Harlem; the financial companies in Lower Manhattan; technical workers; the government of New York City; and the city's Board of Estimate.

Construction starts

Despite the controversy over the number of stops and routes, a combination of Federal and State funding was obtained. In March 1972, the entire cost of the section between 34th Street and 126th Street, according to the projects Draft Environmental Study, was estimated to be $381 million. In June 1972, it was announced that the UMTA would grant $25 million for the construction of this section of the line. The MTA had requested $254 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 million. The entire section was to be constructed using the cut-and-cover method of subway construction, in which a trench is dug in the middle of the street and later covering over it. 14,300 square yards of decking were to have been used to cover the trench, allowing for traffic on Second Avenue to not be interrupted. The entire line from Water Street to 180th Street in the Bronx was expected to be completed by 1980. On September 13, 1972, construction work on Section 11 of Route 132-A, the section between 99th Street and 105th Street, went up for bid, and Slattery Associates of Maspeth, Queens got the low bid of $17,480,266. The MTA board approved the award on September 22, 1972. A groundbreaking ceremony was held on October 27, 1972 at Second Avenue and 103rd Street. Construction began shortly thereafter on the segment. Work on the initial segment was slowed down due to a network of uncharted utility lines below the street. The utilities, as part of the construction, were to be relocated under the sidewalks. Old footings from the Second Avenue Elevated were found while the section was excavated. Another problem in the construction of this segment was the large amount of ground water, which put enormous pressure on the tunnel. An underground substation was constructed at 105th Street, and five feet of concrete had to be poured for the floor so that the structure would not float in the muck.

Construction costs for the entire line were pegged at $1 billion (about $5.726 billion today), and rose to $1.3 billion (about $7.014 billion today) a year later. In December 1972, the NYCTA started soliciting bids for the construction of Section 13 of Route 132-A, which was between 110th and 120th Streets in East Harlem. Bids opened on January 26, 1973, and the bid from Cayuga-Crimmins was the lowest of six bids. The contract was awarded on March 20, 1973, and, in that month, construction of the segment by Cayuga-Crimmins began at a cost of $35.45 million (equivalent to $202,970,000 in 2016). About half of this section was constructed through solid rock and therefore continual blasting was necessary. One worker was killed in the construction of this section.

On October 25, 1973, the line's Chinatown segment commenced construction at Canal Street under the foot of the Manhattan Bridge; this segment, between Canal and Pell Streets, was due to be completed by 1980 and was being built at a cost of $8.3 million (equal to about $44,779,000 in current dollars). The segment was constructed by the Horn–Kiewit Construction Company. In January 1974, a contract, D-21308, was put out for the construction of Section 7 of Route 132-C, which spanned an area between 2nd Street and 9th Street in the East Village. On July 25, 1974, construction on the segment was started near Second Street by Slattery Associates. Another contract, for a Midtown segment between 50th and 54th Streets, was awarded that year for $34.6 million, with constructed expected to begin in the fall. However, construction never commenced. In total, construction on the Second Avenue Line during the 1970s spanned over 27 blocks.

The city also changed zoning regulations for areas located near planned stations, being first proposed on September 30, 1974 by Mayor Beame. New and existing buildings in these areas were required to build pedestrian plazas and arcades that would allow for the future construction of subway entrances. Permanent special transit use districts were created within 100 feet of the proposed stations. The line was designed so that Second Avenue could be widened at a later date by narrowing the sidewalks by five feet on either side of the street.

Construction halts

In spite of the optimistic outlook for the Second Avenue line's construction, the subway had seen a 40% decrease in ridership since 1947, and its decline was symptomatic of the downfall of the city as a whole. A $200 million subsidy for the MTA, as well as a 1952 fare increase from 30 cents to 35 cents, was not enough to pay for basic upkeep for the subway system, let alone fund massive expansion projects like the Second Avenue Subway. In 1971, the subway had been proposed for completion by 1980, but just two years later, its completion date was forecast as 2000.

The city soon experienced its most dire fiscal crisis yet, due to the stagnant economy of the early 1970s, combined with the massive outflow of city residents to the suburbs. 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. On December 13, 1974, New York City mayor Abraham Beame proposed a six-year transit construction program that would reallocate $5.1 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. The plan also used Federal aid to stabilize the transit fare. On December 22, 1974, the Regional Plan Association, a nonprofit research and planning agency for the metropolitan region, urged Mayor Beame to continue building the Second Avenue line, and the group described his decision to postpone the line's construction as a "serious error" that would waste millions of dollars. In September 1975, Beame issued a stop-work order for the line. Construction of the line was halted on the section between Second and Ninth Streets, and no other funding was to be allocated to the line's construction. Besides the Chrystie Street Connection, only three sections of tunnel had been completed; these tunnels were sealed.

By 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. 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 in Long Island City, Queens, but it did not include a connection to the Second Avenue line. In 1996, New York Magazine jokingly suggested that if New York City were to host an Olympic Games, there might finally be funding to finish the Second Avenue Subway. 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."

Segments completed

When construction on the line was halted in 1975, three tunnel segments were completed: one from 99th to 105th Streets and a second from 110th to 120th Streets, both under Second Avenue in East Harlem, and a third from Pell to Canal Streets in Chinatown, under the Confucius Apartments complex next to the Bowery. They were not initially outfitted with track or signals. In August 1982, the MTA put out advertisements in national journals announcing that the two tunnel segments in East Harlem were being put up for rent for temporary use, and that the rents on the tunnels were to last seven years. After the UMTA approved the MTA's plan, the MTA dispersed advertisements. The tunnels had no plumbing, ventilation, or access to the street, except through manhole covers on Second Avenue. To provide access to the tunnels, the MTA would have rented street-level rights that it had for subway entrances. Over the next few decades, the MTA regularly inspected and maintained the tunnel segments (spending $20,000 a year by the early 1990s), to maintain the structural integrity of the streets above, and in case construction would ever resume. Trespassers would often camp in the tunnels until the MTA increased security.

The tunnel section from 110th to 120th Streets was built with three tracks, and as part of the 1970s construction plan, under which this segment was constructed, there was no station planned at 116th Street. The middle track in that area was to be used as an "inspection track" to inspect trains.

The modern construction plan for the Second Avenue Subway, developed in 2004, would make use of most of these tunnel segments. Phase 1 of service built new tunnels up to 99th Street, where the new tunnels connect to the tunnel segment between 99th and 105th Streets. The new tunnels between 96th and 99th Street are used for train storage of up to four trainsets, or two per track. By mid-2013, work had resumed in this tunnel segment, involving upgrading mechanical and plumbing equipment, and upgrading the tunnels to meet modern fire code standards. Phase 2, which does not have a set timetable for construction, is planned to extend Q train service from 96th Street to 125th Street. During Phase 2, both East Harlem segments will be connected, modified, and used for normal train service. In 2007, the MTA reported that the segments were in pristine condition. In December 2016, there were rumors that the 110th–120th Streets segment may go unused, though the MTA refuted the claim.

The fourth phase of construction will bring the Second Avenue line through Chinatown at an undetermined date. However, the tunnel under the Confucius Apartments is not planned to be used; while original plans involved the Second Avenue line running at the same depth of the Sixth Avenue Line at the Grand Street station, that option would require the utilization of cut-and-cover construction methods, which would disrupt the community and require the demolition of several nearby structures. Instead the MTA has proposed a deeper tunnel alignment in this area, including a new lower level at Grand Street, to reduce construction impacts on the Chinatown community. As a result, trains will be unable to use this tunnel segment; however, the MTA suggests that the tunnel segment could be used to store ancillary facilities for the subway line, such as a power substation or a ventilation facility.

Some construction work also took place between 2nd and 9th Streets, though the extent is disputed. Some reports say that only utilities were relocated, while others say that this section was excavated but later filled back in.

2000s–present: Construction and development

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. 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. The line sees an average of 1.3 million daily riders. This is more than the daily ridership of the entire Washington Metro system, which has the second-highest ridership in the U.S., as well as greater than the combined riderships of the rail transit systems of San Francisco and Boston. Local bus routes are just as crowded during various times of the day, with the surface Second Avenue Line, carrying the M15 and M15 SBS buses, which see a combined annual ridership of 14.5 million or a daily ridership of about 46,029.

The construction of the Second Avenue line would add another two tracks to fill the gap that has existed since the elevated Second and Third Avenue Lines were demolished in the 1950s. It would also be the largest expansion of the New York City Subway since the 1960s. According to the line's final environmental impact statement, the catchment area of the line's first phase would include 200,000 daily riders.

1995–2007: Planning

In the early 1990s, then-New York Governor Mario Cuomo allocated $22 million to renew planning and design efforts for the Second Avenue line, but in 1993 the MTA, facing budget cuts, removed these funds from its capital budget. 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. The study analyzed several alternatives, such as improvements to the Lexington Avenue Line to increase capacity, enhanced bus service with dedicated lanes, and light rail or ferry service on the East Side.

The favored alternative, build alternative 1, included a subway running down Second Avenue from 125th Street in Harlem to the existing Lexington Avenue–63rd Street station with provisions for expansion to the Bronx and to Lower Manhattan. Second Avenue was chosen over Third Avenue, because Third Avenue was too close to the Lexington Avenue Line, as well as having significant property impacts, increased construction complexity and cost, and increased travel times resulting from slower operating speeds. Second Avenue was chosen over First Avenue, because it would be too difficult to construct near the Queensboro Bridge, the United Nations and the Queens-Midtown Tunnel.

In November 1997, the MTA initiated the Lower Manhattan Access Study (LMA) to improve access to Lower Manhattan from the New York City suburbs. The construction of the Second Avenue Subway from 63rd Street to Lower Manhattan was one of the five build alternatives developed by the study.

Route proposals

The 1999 DEIS only proposed new subway service from 63rd Street north up Second Avenue to 125th Street via the Broadway Line to Lower Manhattan. All trains would have been routed down the Broadway Line express tracks, which are the only tracks on the Broadway Line which connect to the 63rd Street Line. In order to provide access to Lower Manhattan, and to allow for congestion reduction on the Lexington Avenue Line, the "Canal Flip" was proposed. As built, the tracks at Canal Street are set up so that the local tracks continue into the Financial District and then enter Brooklyn through the Montague Street Tunnel, while the express tracks continue to Brooklyn directly, crossing the Manhattan Bridge. The "Canal Flip" would have flipped the local and express tracks at Canal Street, having local trains run via the Manhattan Bridge, and in turn having the express trains continue south on the Broadway Line through Lower Manhattan and through the Montague Street Tunnel into Brooklyn. Once the construction of full-length Second Avenue Subway was approved, this option was discarded.

The service plan with the "Canal Flip," according to the December 1998 "Manhattan East Side Transit Alternative Study," would have had R trains run via the Second Avenue line, which was only planned to run from 63rd Street to 125th Street. R trains would become the Broadway express under this plan, using the BMT 63rd Street Line to access the Second Avenue line and continuing to 125th Street. The service would have operated 25 trains per hour (tph) between 125th Street and City Hall, 20 tph between City Hall and Whitehall Street, and 10 tph between Whitehall Street and Bay Ridge–95th Street via the Montague Street Tunnel. A reconstruction of a junction near Canal Street, called the "Canal Flip," would have provided a direct connection between the express tracks of the Broadway Line and Lower Manhattan, allowing the route to operate. To replace the R on Queens Boulevard, a Broadway Local T route (distinct from the currently proposed Second Avenue Local T route) would have been created, running between Continental Avenue and Bay Parkway via Broadway local and the Manhattan Bridge. The Canal Flip would have provided a direct connection between the local tracks and the Manhattan Bridge. The N, which ran local on Broadway, would have been rerouted from the Montague Street Tunnel to the Manhattan Bridge.

Initially, a spur to Grand Central Terminal was considered, which would have run via 44th Street as a way to divert riders from the 4 5 routes, which run express on the Lexington Avenue Line. Service on this spur could not be as frequent as that on Lexington Avenue as there would not be enough capacity on Second Avenue, and as a result this plan was dropped.

South of 14th Street, there were two possible options to decide between. Option A would continue the subway beneath Chrystie Street, St. James Place and Water Street to a terminal in Lower Manhattan. Option B would connect the new subway to the existing Nassau Street Loop tracks J1 and J2 at Kenmare Street to provide access to Lower Manhattan. This option has been proposed as part of plans for the Second Avenue Subway from the 1940s and 1950s. Cross-platform transfers would be available at Canal Street and Chambers Street to the Nassau Street Line routes. It would allow Second Avenue trains to have access to Brooklyn using the underutilized Montague Street Tunnel. This option would have a lower cost than the Water Street option as there would be less tunnel needed to be constructed. The Nassau option would attract more riders to the subway system because of additional service to Brooklyn, but the Water Street option would provide greater coverage in Manhattan and would be better at relieving congestion on the Lexington Avenue Line. Because the platforms on the BMT Eastern Division are shorter than those on the rest of the B Division, those on the Nassau Street Line south of Chambers Street would have to be lengthened by about 120 feet (37 m), to a total of 615 feet (187 m). The tracks would have to be reconfigured, the passenger circulation capacity would have to be increased, and the service plan south of Chambers Street would have to be modified, to provide sufficient capacity to accommodate the additional trains that Second Avenue Subway service would require. The Nassau Street Line connection would have run through a new tunnel that first turns to the east to align under Forsyth Street before turning west and joining the Nassau Street Line along Kenmare Street.

The Water Street option was chosen even though it would cost $360 million more because of the additional benefits it would provide. The Nassau Street option would have required the reorganization of the existing services on the Nassau Street Line, and passengers entering via the Williamsburg Bridge would not have direct service to destinations in other parts of Brooklyn. Additionally, over a period between two and three years long, service on the Nassau Street Line would have been required to be shut down during late nights and/or weekend hours. The Nassau Street option would not have the capacity for future Queens service via the 63rd Street Tunnel.

Originally, the 125th Street station was to have been constructed parallel to the Lexington Avenue Line, curving below private property to join Second Avenue at 115th Street. This option was favored as it would have allowed an eventual extension of the Second Avenue Subway to the Bronx via the IRT Pelham Line, while still providing a transfer at 125th Street to the Lexington Avenue Line. Under this option, 116th Street would not have a station, but because of requests by the local community, the SDEIS evaluated the inclusion of this station. The s-curve options were out of the question because of the large curve radius required for efficient and fast subway operation. As a result, the alignment at 125th Street was changed. Instead, the line would continue via Second Avenue until 125th Street, when it would then curve under a small number of private properties before heading west on 125th Street. A future extension to the Bronx would be allowed from Second Avenue as opposed to Lexington Avenue. This alignment also allows for the construction of a storage yard north of 125th Street.

Build alternative two would involve the addition of a separate light rail service between Union Square and Broad Street that would serve the Lower East Side and Lower Manhattan. Other alternatives including building in-fill stations on various lines (including the 63rd Street Line at First Avenue, at First Avenue on the Broadway Line, at First Avenue on the Flushing Line, and Avenue C on the Canarsie Line), building an elevated train line along Second or First Avenues, lengthening the platforms on the Lexington Avenue Line to accommodate twelve-car trains, or connecting the northern part of the Lexington Avenue Line (either the local or express tracks), which would be converted to B Division service, to the Broadway Line 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. In May 2000, the MTA Capital Program Review Board approved the MTA's 2000–2004 Capital Program, which allocated $1.05 billion for the construction of the Second Avenue Subway. In 2001, a contract for subway design was awarded to DMJM Harris/Arup Joint Venture. On December 19, 2001, the Federal Transit Administration approved the start of preliminary engineering on a full-length Second Avenue Subway.

Approval and preparation for construction

When Hillary Clinton was running for New York State Senator in 2000, she stated that she supported the construction of multiple major infrastructure projects in New York, such as the Second Avenue Subway, East Side Access, and rail links to LaGuardia and JFK Airports. In 2003, two million dollars in preliminary funding for the subway were provided by Congressmen Maurice Hinchey and John Sweeney. The MTA's final environmental impact statement 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 in the Financial District.

The new subway line will actually carry two regular services. The full-length Second Avenue line, extending from Harlem to the Financial District, is to be given the color turquoise and the letter designation T. However, a rerouted Q, the line's other service, will begin carrying passengers first (supplemented by some rush-hour N trains). The MTA plan calls for building the Second Avenue Subway in four segments with connections to other subway lines. The first segment (Phase One) is a proposed reroute of the Q, the Broadway Express via the BMT 63rd Street Line and north along Second Avenue to the Upper East Side at 96th Street. Phase Two will extend the rerouted Q train, along with the rush-hour N trips, to 125th Street and Lexington Avenue. In Phase Three, the new T train will run from 125th Street to Houston Street. The final phase will extend T train service from Houston Street to Hanover Square in Lower Manhattan.

In order to store the 330 additional subway cars needed for the operation of the line, the 36th–38th Street Yard would be reconfigured. In addition, to allow for train storage, alongside the main alignment, there would be storage tracks between 21st Street and 9th Street. The Second Avenue Subway is chained as "S". The track map in the 2004 FEIS showed that all stations, except for 125th Street, would have two tracks and one island platform. 72nd Street and 125th Street were conceived as three-track, two-platform stations, with plans for the former being scaled back. At 72nd Street, this would have allowed trains from the Broadway Line to reverse without interfering with service on Second Avenue, as well as provided additional operational flexibility that could be used for construction work and non-revenue moves. However, to reduce costs, the 72nd Street station was ultimately constructed with two tracks and one platform.

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 station—would be outfitted with air-cooling systems to reduce the temperature along platforms by as much as 10 °F (6 °C). 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, but this plan was scrapped in 2012 as cost-prohibitive.

The 2-mile (3.2 km) first phase will be within budget, at $4.45 billion. Its construction site was designated as being from 105th Street and Second Avenue to 63rd Street and Third Avenue. 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. The total cost of the 8.5-mile (13.7 km) line is expected to exceed $17 billion. In 2014, MTA Capital Construction President Dr. Michael Horodniceanu stated that the whole line may be completed as early as 2029, and would serve 560,000 daily passengers upon completion; however, as of December 2016, only phases 1 and 2 would be completed by 2029. The line is described as the New York City Subway's "first major expansion" in more than a half-century. However, its completion is in doubt, with one construction manager saying that the first phase of the project is "four and a half billion dollars for three stations," and that there are 15 stations that need to be built for the entire line.

Beginning of construction

Second Avenue Subway plans for Phase 1 were only allowed to proceed because New York voters passed a transportation bond issue on November 8, 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 percent of voters approving and 45 percent disapproving. After warning that failure to pass the act would doom the project, MTA chairman Peter S. Kalikow stated, "Now it's up to us to complete the job." On December 18, 2006, the U.S. Department of Transportation announced that they would allow the MTA to commit up to $693 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.

Preliminary engineering and a final tunnel design was completed by a joint venture between AECOM and Arup. The first phase was originally supposed to include a core tunneling section between 62nd and 92nd Streets, as well as a spur from Third Avenue/63rd Street to Second Avenue/65th Street. The 96th Street station cavern, as well as existing tunnels, would allow the first phase's trackage to run from 62nd to 105th Streets. Before construction started, the MTA revised their plans so that the construction of the section between 62nd and 65th Streets was postponed. On March 20, 2007, upon completion of preliminary engineering, the MTA awarded a contract for constructing the tunnels between 92nd and 63rd Streets, a launch box for the tunnel boring machine (TBM) at 92nd to 95th Streets, and access shafts at 69th and 72nd Streets. This contract, valued at $337 million, was awarded to S3, a joint venture of Schiavone Construction, Skanska USA Civil, and J.F. Shea Construction. A ceremonial groundbreaking took place on April 12, 2007, in a tunnel segment built in the 1970s at 99th Street. At the time, it was announced that passengers would be able to ride trains on the new line by the end of 2013. Actual construction work began on April 23, 2007, with the relocation of utility pipes, wires, and other infrastructure. This process took 14 months, nearly double the MTA's anticipated eight months.

In November 2007, Mary Peters, the United States Secretary of Transportation, announced that the Second Avenue Subway would receive $1.3 billion in federal funding for the project's first phase, to be funded over a seven-year period. However, due to cost increases for construction materials and diesel fuel affecting the prices of contracts not yet signed, the MTA announced in June 2008 that certain features of the Second Avenue Subway would be simplified to save money. One set of changes, which significantly reduces the footprint of the subway in the vicinity of 72nd Street, is the alteration of the 72nd Street Station from a three-track, two-platform design to a two-track, single island platform design, paired with a simplification of the connection to the Broadway Line spur. Supplemental environmental impact studies covering the changes for the proposed 72nd Street and 86th Street stations were completed in June 2009.

On May 28, 2009, the MTA awarded a $325 million contract to E.E. Cruz and Tully Construction Co., a joint venture and limited liability company, to construct the 96th Street station box. Work on this contract began in July. In June 2009, the first of three contracts for the 86th Street station was awarded for the advance utility relocation work and construction of cut-and-cover shaft areas at 83rd and 86th Streets.

During construction, two buildings had to be evacuated in June 2009 due to construction work. On June 5, an apartment building at 1772 Second Avenue was evacuated by the NYC Department of Buildings (DOB) after it was determined that the building was in danger of collapse. Then on June 29, the DOB evacuated a mixed use building at 1768 Second Avenue/301 East 92nd Street because it too was in danger of collapse. The evacuation of these two buildings delayed the contractor's plan to use controlled blasting to remove bedrock in the southern section of the launch box. Until the blasting permits could be issued, MTA required contractors to use mechanical equipment to remove the bedrock, which is slower than blasting out the rock.

The tunnel boring machine was originally expected to arrive six to eight months after construction began, but the utility relocation and excavation required to create its "launch box" delayed its deployment until May 2010. On May 14, 2010, MTA's contractors completed the TBM installation and turned it on at the Second Avenue Subway launch box at 96th Street and boring southward to connecting shafts built at 86th and 72nd Streets. On October 1, 2010, MTA awarded a $431 million contract to joint venture SSK Constructors for the mining of the tunnels connecting the 72nd Street station to the existing Lexington Avenue–63rd Street station, and for the excavation and heavy civil structures of the 72nd Street station. A subsequent contract was awarded to Skanska Traylor Joint Venture for excavation of the cavern at the 86th Street station on August 4, 2011. In January 2011, MTA awarded Judlau Contracting a 40-month, $176.4 million contract to rebuild and enlarge the Lexington Avenue–63rd Street station.

Significant progress

Meanwhile, the tunnel boring machine dug at a rate of approximately 50 feet (15 m) per day. The machine finished its run at the planned endpoint under 65th Street on February 5, 2011. S3 partially disassembled the TBM and backed it out of the tunnel. It was repositioned in the east starter tunnel to begin boring again. Because the east side of Second Avenue has some soft ground not compatible with the Robbins TBM, ground-freezing was undertaken to prepare the soil for the TBM. On March 28, 2011, S3, having completed its task of completing the 7,200-foot (2,200 m) west tunnel to 65th Street, began drilling the east tunnel, with the first 200 feet (61 m) being through soil frozen by S3 using calcium chloride solution fed through a network of pipes. The TBM drilling the east tunnel then negotiated the curve onto 63rd Street and broke through the bellmouth at the existing Lexington Avenue–63rd Street station. That bellmouth had been built in the late 1970s and early 1980s as part of the construction of the 63rd Street Line in anticipation of the construction of the Second Avenue line. The portion of the west tunnel remaining to be created was then mined using conventional drill-and-blast methods, because the curve S3 construction teams would have to negotiate was too tight for the TBM. On September 22, 2011, the TBM completed its run to the Lexington Avenue–63rd Street station's bellmouth. This major milestone was celebrated with a big ribbon-cutting to mark the TBM breaking through to the existing bellmouth. The TBM had dug a total of 7,789 feet (2,374 m) for the east tunnel.

The final contract, for architectural and mechanical and electrical work at 72nd, 86th, and 96th Street stations; rehabilitation of the Lexington Avenue–63rd Street station; and the Systems Contract (track, signals, and communications) for the entire Phase 1 area was awarded on June 1, 2013. On a July 2013 "report card" that indicated the progress of the subway by Congresswoman Carolyn Maloney, the construction progress got a "B". Blasting for the station caverns was finished in November 2013, and the muck houses were taken down at around the same time.

In the winter of 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. It was reported in November 2013 that one third of the tracks for the line had arrived, for the segments of track between 87th and 105th Streets; the tracks were being stored at 96th Street station. On May 2, 2014, it was reported that Phase 1 of the line was 66% complete, and six of the ten construction contracts awarded were already being worked on. As of May 21, 2015, the first phase of construction was more than 80% complete. By August 2015, the construction project was 84.3% complete, with all 10 Phase 1 construction contracts having been awarded and 5 of them having been completed.

Push for completion

On February 24, 2016, the MTA allocated $66 million to speed up the construction of the first phase so that it could open in December. However, in June of that year, it was reported that contractors for the MTA were not expending extra resources to accelerate the last portion of Phase 1 construction, and that the MTA had only completed 67% of testing, with the line requiring another 1,100 equipment tests by October 2016 in order to be deemed operational. The contractors and the MTA blamed the delays on each other, with the MTA saying that the contractors did not show up to work on certain days; the contractors, on the other hand, said that the MTA had asked for over 2,500 design changes during construction, and in some cases, the contractors had to destroy and rebuild sidewalks, rooms, entrances, and other design elements that had already been built.

In a public meeting in May 2016, the MTA unveiled the first iteration of the New York City Subway map that included the Second Avenue Subway and a rerouted Q service. At the meeting, the MTA also made several suggestions for service changes, including making the N train express in Manhattan and replacing the Queens section of the Q, as well as the Manhattan local section of the N, with a reinstated W train.

On May 16, 2016, Congresswoman Maloney released another report card on the project. The overall grade improved from a "B" to an "A-", with the caveat that the December 2016 deadline be met. By July 2016, the first phase was 96.3% complete, with only systems testing, architectural finishes, streetscape restorations, and some equipment installations to be completed. However, news outlets reported that the Second Avenue Subway had a "significant risk" of a delayed opening. The test train for the subway line was not set to run until October 2016, despite the line being projected to open within two months of that date. Also, contractors had only reached 70% of the construction milestones for June 2016, and 80% of the May 2016 milestones. For instance, communications systems at the stations were not finished, despite the fact that these systems should have been wired already, and the elevator at 72nd Street had not been delivered yet. As of July 25, 2016, construction spending was only $32 million for the month, even though a monthly spending goal of $46 million was needed to complete the project on time.

The electrification in the third rails went online for train testing in September 2016 to test if the tracks are "safe for service" yet. Non-revenue Q trains ran through the subway in November 2016. Test trains began running through the new line on October 9, 2016 with weights to simulate rush hour loads, even though equipment installations at two stations, as well as a battery of tests, still needed to be completed in order for the line to be opened to passenger service. Shortly before the first test trains ran, the system's track geometry car determined that the twin bores of the 63rd Street Connector were too narrow for trains consisting of 75-foot (23 m) cars (i.e. trains made of R46s, R68s, or R68As) to enter the line. To accommodate trains of these longer cars, crews shaved down parts of the tunnel walls by mid-October 2016, in time for the test trains. Also in October, new subway signs and maps were erected systemwide in relation to Second Avenue Subway-related service changes. More than 1,300 signs were installed in over 40 stations.

By late October, the testing for elevators and fire alarms at 72nd Street still had not been completed, and the MTA said that there was a possibility that the subway could open with trains temporarily bypassing 72nd Street. This had been done before in September 2016, when subway trains in Chelsea temporarily bypassed several stations along 23rd Street due to bombings. There was a concern that 86th Street was also not completed, with three escalators not installed yet. The two stations were only conducting 14 equipment tests a week, but there needed to be 40 tests per week in order to ensure that the line would open on time. The tentative opening date was also clarified to "by December 31," with a possibility of a delayed opening. However, an engineer affiliated with the MTA stated that there was a possibility that the line could be delayed to 2017.

In November 2016, an independent engineer on the project raised concerns, including whether the required fire safety testing could be completed by December 15. That engineer said that "unprecedented" work was required to complete the line by the year's end. December 31 was still the planned opening date, but there have been logistical and safety concerns about the line's opening on New Year's Eve. Following this, the MTA ordered that contractors finish all remaining construction on the Second Avenues Subway before December 31. Contractors were asked to work double shifts, with all remaining fire and equipment tests to be conducted on a 24-hour-per-day, 7-day-per week schedule so that the December 31 deadline could be met. By December 5, the opening date still had not been finalized, and there still remained a chance that the line would not open until 2017.

Governor Andrew Cuomo (son of former Governor Mario Cuomo, who had allocated funding to the line) was leading the push to open the subway before year's end. On December 10, Governor Cuomo visited two under-construction Second Avenue subway stations, later stating that he was "cautiously optimistic" that the line would open before the New Year. However, as of the MTA board's monthly meeting, which occurred two days after Cuomo's visit, the subway's opening date had still not been finalized. On December 12, Cuomo visited the 96th Street station for at least his third trip in four days. At that time, officials were hoping that the final tests would be finished before December 22. The New York Times observed that Governor Cuomo's enthusiasm to open the line by December 31 stemmed from an incident that had occurred about a year and a half earlier, where officials at the MTA told him that they wanted to push the opening date back a year or two. However, several unidentified individuals have criticized Cuomo for these actions, saying that the increased involvement in the project served merely to improve his reputation. On December 14, the MTA finally announced that December 31 would be the probable opening date for the line, with all of the line's stations to open at the same time. A day later, MTA chairman Thomas Prendergast stated that the three new stations would all open at the same time, even if that meant delaying the opening of the subway.

Schedules for construction and opening

The MTA and its contractors on the project met on a regular basis with the Manhattan Community Board 8 Second Avenue Subway Task Force and Manhattan Community Board 11 to report on construction progress and to seek input from the community.

Estimated completion schedules slipped over time. When the bond issue to fund the construction was passed in 2005, the MTA said that the project would be done in 2012. This quick completion date was a part of the city's unsuccessful 2012 Summer Olympics bid; the Olympics were hosted in London instead. When construction began in 2007, the MTA stated that the new train line would open by the end of 2013. Later in 2007, another the MTA gave a completion date of 2014. In its 2008 capital improvement budget proposal, the MTA pushed back completion of Phase 1 to 2015, and in 2009, the MTA pushed it back again to 2016. Some publications had predicted the December 2016 opening. Others reported that the subway would not open until 2017.

By May 2014, the agency was still targeting December 2016 as the completion date, and the project was still within its $4.45 billion budget, and still estimated to serve approximately 200,000 daily riders. By January 2015, the MTA's forecasted opening date for Phase I had been clarified even further, to around December 30–31, 2016, with Horodniceanu describing earlier estimates as lacking "the precision required." In June 2015, however, the federal government predicted that at the then-current rate of construction, the subway would not open until February 2018. After Governor Cuomo's intervention, the deadline was reset to December 31, 2016. On December 19, the start of revenue service was announced as noon on January 1, 2017. The confirmed New Year's opening date was attributed to testing being completed at a faster pace than expected. Of the New Year's Day opening date, Cuomo stated:

This January 1 deadline was a little arbitrary, because it was set back in 2009. And since 2009 a lot has happened and a lot of adjustments have been made. The first instinct is, well let’s move the deadline. And we thought it was important to keep the deadline and that we make this deadline, especially on this project that has become notorious for delay after delay.

Opening

On December 27, non-revenue testing of the line started; Q trains began to follow the regular schedule to 96th Street after discharging all passengers at 57th Street. On December 22 and 23, 2016, as part of an open house hosted by the MTA, the public was invited to tour the 96th Street station before it opened, to generally positive reaction. There was another open house on December 30, this time at the 86th Street station. The entrance to the Lexington Avenue–63rd Street station at Third Avenue, which was completed as part of Phase 1, was also opened on that date. The MTA made new maps in preparation for the extension, with 12,900 new maps for subway car interiors; 1,000 new maps for stations; and 150,000 new portable, multilingual maps in eight languages besides English.

The ceremonial first train, with Governor Cuomo, Mayor Bill de Blasio and other public officials, left 72nd Street on New Year's Eve shortly after 10:30 p.m., toward 96th Street. A party was held at the 72nd Street station. The next day, on January 1, 2017, the first train left from 57th Street heading uptown. The stations on the first phase opened at 11:45 a.m, and the first trains arrived at about noon. On opening day, the stations were crowded with passengers seeking to check out the new line. About 48,200 passengers entered the new stations on that day, excluding passengers who toured the line by entering at a station in the rest of the system. The line opened to generally positive acclaim, though there were complaints about dirty trains, signal delays, and malfunctioning elevators. Some trains of R160 subway cars were wrapped in Second Avenue Subway livery to celebrate the line's opening. The 96th, 86th, 72nd, and 63rd Street stations featured new artwork by artists Sarah Sze, Chuck Close, Vik Muniz, and Jean Shin, respectively.

On January 3, the first date on which the line began operating under a weekday schedule, some rush hour N trains started using the line. During the opening week of operation, trains were running every six minutes during peak hours, and there was no service between 10 p.m. and 6 a.m. Overnight service began on January 9, 2017. This was so finishing touches could be placed on the station overnight to avoid leaks and other major issues like those found in the new 34th Street–Hudson Yards station, which had opened a year prior. In January 2017, compared to January 2016, ridership on the Lexington Avenue Line at the 68th Street, 77th Street, 86th Street, and 96th Street stations decreased because of the opening of Phase 1. The main decrease in ridership was at the 86th Street station, where more than 28,000 of its 120,000 daily riders switched to using the Second Avenue Subway. Overall, 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.

Controversies

In February 2011, a lawsuit was filed by the Yorkshire Towers at 86th Street over the location of two proposed Second Avenue Subway entrances that were located right in front of the building but facing away from its semicircular driveway citing quality of life issues. However, the lawsuit was later dismissed.

In an unrelated 2012 controversy, some residents in the 72nd Street station area claimed to have come down with a "Second Avenue cough" caused by dust from construction, and local doctors saw that the air quality of the area had decreased while nasal sicknesses had increased. The MTA tried to combat this by creating new structures and using other methods to reduce dust inhalation. The MTA prepared a report that said in the 86th Street station area "all monitored concentrations were below the established benchmark levels".

The New York Daily News alleged that the subway project was very unsafe. For example, on August 8, 2012, an explosion caused rocks to fly all over an intersection. Less than two weeks later, on August 21, 2012, an uncontrolled blast for the station was done incorrectly, causing a large explosion that sent debris into the air and broke windows of buildings in the area and damaged nearby sidewalks. In another instance, contaminated rocks were carried away from a construction site on 63rd Street, and the incident went unnoticed. On March 19, 2013, in yet another allegation of wrongdoing, a construction worker got stuck in waist-deep muck at the 96th Street station site, but while he was extricated after four hours of rescue efforts, he nearly died after the incident.

Other complaints included noise complaints caused by blasting underground. In response to this, the MTA limited blasting to before 7 p.m. each day.

In a product-related controversy involving the Second Avenue Subway project, American Standard Testing and Consulting Laboratories (ASTCL), company president Alan Fortich, and five other executives admitted filing false documents on the subway tunnels and "thousands" of other New York City construction projects within 10 years. ASTCL had replaced Testwell Inc., another firm indicted for faking concrete tests, in 2008.

Phase 2

The second phase, between 125th and 96th Streets, was allocated $525 million in the MTA's 2015–2019 Capital Plan for planning, design, environmental studies, and utility relocation. This phase will complete the project's East Harlem section. The alignment will run under Second Avenue to 124th Street, before turning west on 125th Street, crossing Lexington Avenue, before ending at Fifth Avenue to accommodate storage tracks. This phase will utilize a tunnel section built during the 1970s from 110th Street to 120th Street and this section will have tracks and other essential equipment installed. Three new stations will be constructed at 125th Street, 116th Street, and 106th Street. Because a station at 116th Street was not part of the plan for the Second Avenue Subway when the existing tunnel section was built, part of the tunnel will have to be rebuilt to allow for a station at 116th Street. A transfer to the Lexington Avenue Line and an intermodal connection with Metro-North Railroad would be available at the 125th Street station. While the main line would turn west onto 125th Street, tail tracks would continue north via Second Avenue to 129th Street that would allow for future expansion into the Bronx. Tail tracks that extend 525 feet west of Fifth Avenue would allow for the construction of a crosstown line under the busy 125th Street corridor. These tail tracks would also allow for trains to enter the 125th Street terminal at speeds that would allow for the operation of 30 trains per hour on the line, in addition to allowing for the storage of four trains.

This budget originally carried $1.5 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. Now, construction of the tunnels will likely be funded in future 5-year capital programs, and possibly not start until 2020. Although the MTA previously expressed concerns about funding the Capital Program, spokesman Adam Lisberg stated that the reduction in funding was a result of uncertain timing and not money problems. The delay had upset politicians and residents of East Harlem, who objected to the 3-to-4-year delay. In March 2016, the MTA began advertising Requests for Proposals (RFP) for three new contracts for the second phase, which were planned to be awarded in summer 2016. 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 billion allocated. $535 million will be used to undertake preliminary construction work, such as relocating utilities, and for the design of the project, and to address environmental problems. The next $500 million would be used to prepare work for tunneling and station construction.

On October 18, 2016, the de Blasio administration announced a rezoning plan for East Harlem. The plan would alter special transit zoning created in the 1970s for the Second Avenue Subway. Incentives would be offered to integrate subway infrastructure into new buildings. This is meant to improve pedestrian conditions adjacent to ventilation buildings. There would be three Special Transit Land Use (TA) districts; one for the area of the 106th Street station, one for the area of the 116th Street station, and one for the area of the 125th Street station.

On November 21, 2016, the MTA requested that the Phase 2 project be entered into the Project Development phase under the Federal Transit Administration's New Starts program. On December 15, several elected officials for the area announced that they were seeking $6 billion of funding for Phase 2 of the line, including $2 billion from the federal government. These officials wished to secure funding from the presidential administration of Barack Obama before Obama's term ended on January 20, 2017. In their request for funding, they cited that they wanted to avoid an uncertain response from the administration of Donald Trump and start construction on Phase 2 as soon as possible. The FTA granted this request in late December 2016. Under the approved plan, the MTA would complete an environmental reevaluation by 2018, receive funding by 2020, and open Phase 2 between 2027 and 2029.

In January 2017, it was announced that Phases 2 and 3 of the subway was among the 50 most important transportation projects nationwide that the Trump administration wants to build. The combined project, ranked 18th on the list, is expected to cost up to $14.2 billion.

The construction of Phase 2 will be built with options for future expansions into the Bronx. A bellmouth would be constructed along Second Avenue north of 125th Street as part of a proposed underground storage yard that extends to 129th Street.

Phase 3

Phase 3, from 63rd to Houston Streets, has no funding commitments. Phases 2 and 3, classified as a high-priority project by the Trump administration, may cost up to a combined total of $14.2 billion.

Phase 4

Phase 4, which also has no funding commitments, will provide an extension from Houston Street to a permanent terminus, with storage tracks, at 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 located near Peter Minuit Plaza at a depth of 110 feet. 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.

With the Hanover Square station planned to be located 85 feet (26 m) below sea level, the elevation 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.

Construction methods

Planned construction methods varied depending on the section of the line, due to varying underground conditions. The methods planned for each section were confirmed in 2003. In a follow-up report published in 2016, the planned construction methods above 120th Street were revised.

A number of methods will be used to tunnel for 13.7 kilometers (8.5 mi) underneath Manhattan, which is densely populated. About 90% of the tunneling is to be performed by a tunnel boring machine. The rest will be done using the cut-and-cover method or mined drill-and-blast for sections averaging 275 meters (902 ft) in length, namely the station boxes. 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 15 meters (49 ft) 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. Stations at the two mined stations are between 25.9 and 27.4 meters (85 and 90 ft) deep in rock. 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.

In Phase 1, there was tunneling between East 63rd and 92nd Streets and a 248-by-23-meter-wide (814 by 75 ft) TBM launch box was built. That tunnel box is now part of the 96th Street station. Two access shafts were constructed for the 72nd Street station. Slurry or diaphragm walls, 1.1 meters (3.6 ft) wide and 6.1 meters (20 ft) long and about 35 meters (115 ft) deep, were built alongside the sections between East 93rd and 95th Streets. Since the rock is shallower between East 91st and 93rd Streets, 1.1-meter-diameter (3.6 ft) secant piles did the same work at shallower depths. Earth excavation was conducted between walls once they were installed, and box structures were built using a bottom-up construction method. Temporary decking constituted the top of the boxes, and the decking both braced the excavation and supported the walls and Second Avenue traffic.

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." 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. In addition, 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, silts, and clays over Manhattan schist, and there are faults and shear zones as well as fractured rock. Hard-rock TBMs 6.7 meters (22 ft) in diameter, 450 feet (140 m) in length, and 485 short tons (433 long tons) in weight were used to tunnel during the first phase, progressing at a rate of about 20 meters (66 ft) per day. 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).

There are three options for subway construction 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 Option would use a combination of the Earth Pressure Balance Machine (EPBM) and cut and cover. The Shallow Chrystie Option would have used the existing Confucius Plaza tunnel section between Canal and Pell Streets, and like the 1974 plan, there would have been a cross-platform transfer to the existing Grand Street station, with the transfer expected to be heavily used. However, this option would require digging up Sara D. 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. 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 it might be used for ancillary subway facilities. Currently, this is the preferred option.

The stations on the line were built so that they are more wide open than most other underground subway stations in the system; because of this, Horodniceanu likened the Second Avenue Subway stations to the stations on the Washington Metro. The tracks themselves are built atop rubber padding so as to reduce the noise from the trains.

Cost

There was controversy over the high cost of the line as a whole. Phase 1 ended up costing $500 million over its original budget of $4 billion—still a very high price compared to other new subway systems worldwide. This was attributed partly to high labor costs, which were exacerbated by relatively low productivity due to the regulations of these workers' trade unions. One reporter for The Daily Beast commented that in Europe and in U.S. states that do not require unions, the number of workers required could be reduced by 50% to 80%. In addition, regulations set by the Buy America Act forced the MTA to purchase materials made in the United States, which led to objections when an MTA contractor bought a fire suppression system made in Finland. Finally, the private and public sector could not cooperate smoothly on the project, further raising costs. Of the $4.5 billion cost for Phase 1, $2.4 billion was allocated to building the three new stations and renovating the Lexington Avenue–63rd Street station. Meanwhile, $500 million was spent on design and engineering, and another $734 million was for building tunnels between the stations, tracks, signals, and trackside systems. The rest of the cost, $800 million, was spent on "construction management, real estate, station artwork, fare-collection systems and other sundry items." 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 projects such as London's Crossrail.

In December 2016, after it was announced that Phase 2 might cost $6 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. 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. MTA officials stated that the Second Avenue Subway cost as much as it did only because of the various complex underground infrastructure in Manhattan, as well as the fact that the New York City Subway runs all the time.

Routes

The opening of Phase 1 extended Q service to 96th Street from its former terminal at 57th Street. The Q service has a rush-hour service frequency of 7 to 10 trains per hour,; by contrast, the IRT Lexington Avenue Line's express tracks (4 5 trains) have an estimated rush-hour frequency of 30 trains per hour, or one train approximately every 2 minutes in each direction. As part of the 2004 Final Environmental Impact Study (FEIS) for the line, Q service was planned to have a frequency of 14 trains per hour during rush hours, but this was revised due to MTA schedule changes. A few rush hour N trains that formerly short-turned at 57th Street began to run to 96th Street on January 3, 2017.

In Phase 2, Q and N service will be extended to 125th Street and Lexington Avenue. As part of the 2004 FEIS, it was planned for Q service to be increased to 19 trains per hour to accommodate the projected increase in ridership. In order to allow for the construction of Phase 3, bellmouths have been constructed at the turnoff to the BMT 63rd Street Line.

Future full-length designation

When the construction of Phase 3 is completed, a new T service will operate from 125th Street to Houston Street. After Phase 4 opens, T service will run the full length of the line, from 125th Street to Hanover Square. 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 trains per hour back to 14 trains per hour.

The MTA decided to designate the future service with the letter T, in part because:

The T's route emblem is colored turquoise (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 also considered a very upscale color.

Station listing

Three stations are part of phase 1, which opened on January 1, 2017. 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).