Second Avenue Subway Phase 2 to Cost $6 Billion

Since the 2015-9 capital plan, the New York MTA had been including the second phase of Second Avenue Subway in its capital plan, without a clear estimate of its projected cost. The rumors said the cost would be about $5 billion. A new media story finally gives an official cost estimate: $6 billion. The total length of the project, from 96th Street and 2nd Avenue to 125th Street and Lexington, is about 2.7 km. At $2.2 billion per km, this sets a new world record for subway construction costs, breaking that of the first phase of the same line, which only cost $1.7 billion per km. See a compendium of past posts here to look how these projects stack up. For people not interested in combing through multiple old posts of mine, the short version is that outside the Anglosphere, subway tunnels typically cost $100-300 million per km, with outliers in both directions, but even inside the Anglosphere, costs are in the mid-to-high hundreds of million per km.

In some way, the high cost of SAS phase 2 is more frustrating than that of phase 1. This is because 1 km of the 2.7 km of route preexists. SAS construction began in the 1970s, but was halted due to New York’s financial crisis. In East Harlem, some actual tunnel segments were dug, roughly between the proposed station locations at 96th, 106th, 116th, and 125th Streets; Wikipedia has a more detailed list. Construction of phase 2 thus involves just the stations, plus a short bored segment under 125th Street to get from Second Avenue to Lexington, for a connection to the 4, 5, and 6 trains.

Not having to build tunnels between the stations is beneficial, not as a cost saver in itself but as a way to reduce station costs. In phase 1, it appears that most costs were associated with the stations themselves; if I remember correctly, the cost breakdown was 25% for each of three new stations, and 25% for the tunnels in between. The reason is that the stations are quite deep, while the tunneling in between is bored, to reduce surface disruption. Deep stations are more expensive because they require more excavation, while tunnel boring costs depend more on soil type and how much infrastructure is in the way than on depth. Counting the extra expense of stations, bored subways cost more per km than cut-and-cover subways, but create less surface disruption away from station sites, which is why this method was chosen for phase 1. In contrast, in phase 2, most construction is stations, which would favor a shallow cut-and-cover solution.

Unfortunately, according to rumors, it appears that the MTA now judges it impossible to use the preexisting tunnels in phase 2. If this is true, then this would explain the higher cost (though it would justify $400 million per km, not $2.2 billion): they’d have to build underneath those tunnels. But if this is true then it suggests severe incompetence in the planning stage, of the kind that should get senior employees fired and consultants blacklisted.

The reason is that Second Avenue Subway was planned as a single line. The Environmental Impact Statement was for the full line, including the proposed construction techniques. The phasing was agreed on by then; there was only enough state money for phase 1. This isn’t an unexpected change of plans. I’d understand if in the 2000s it was found that tunnels from the 1970s were not usable; this happened further south, in phase 4, where a preexisting tunnel under Chrystie Street was found to be difficult to use. But in the 2000s the SAS studies signed off on using the tunnels in Harlem, and what seems to be happening is that phase 1, built according to the specifications of the same study, is too deep for using the tunnels.

At $6 billion, this line shouldn’t be built. I know that it goes to a low-income, underserved neighborhood, one that I’ve attacked New York before for taking years to equip with bike lanes (scroll down to my comments here). But the ridership projection is 100,000 per weekday, and $60,000 per weekday rider is too much. Phase 1, providing an underrated east-west connection and serving a denser neighborhood, is projected to get 200,000, for a projection of around $25,000 per weekday rider, which isn’t terrible, so it’s a justified project even if the costs could be an order of magnitude lower.

Were costs lower, it would be possible to build subways to many more low-income neighborhoods in New York. A 125th Street crosstown line, extending phase 2 of SAS, would provide Harlem with crucial east-west connectivity. Subways under Nostrand and Utica Avenues would serve a mixture of working- and middle-class neighborhoods in Brooklyn. A subway under Northern Boulevard in Queens, connecting to phases 3 and 4 of SAS, would serve one of the poorest parts of Queens. A network of tramways would improve surface transit in the South Bronx. Triboro Line would connect poor areas like the South Bronx and East New York with richer ones like Astoria. New York could achieve a lot, especially for its most vulnerable residents, if it could construct subways affordably.

But in a world in which subways cost $60,000 per weekday rider and $2.2 billion per km, New York cannot extend the subway. If it has money in its budget for investment, it should look into things other than transportation, such as social housing or schools. Or it could not borrow money at all to pay for big projects, and in lieu of the money spent on interest, reduce taxes, or increase ongoing social spending.

Given persistent high costs, I would recommend shelving SAS and future rail extensions in New York, including the Gateway tunnel, until costs can be drastically cut. There’s no shortage of worthy priorities for scarce budget in New York, both city and state. Health care in the US is too expensive by a factor of 2, not 10, and transfer payments have near-100% efficiency no matter what; it’s possible to exhaust the tax capability of a state or city just on these two items. Perhaps the need to compete with other budget priorities would get the MTA to cut waste.


  1. Comradefrana


    I find this hard to believe. Because unless every info about SAS I’ve found on the internet is wrong, phase 1 was already supposed to be using the preexisting tunnel between 99th and 105th streets as tail/storage tracks for the 96th street station. Which is also why it was build cut-and-cover 15m below the ground compared to being mined ~25m below the ground for the 86th and 72nd street stations.

    I thought that maybe what was actually built is different from what was planned, but that doesn’t seem to actually be the case. This: cab view video from a test train clearly shows a long cut-and-cover tunnel north of the 96th street station.

    So what I’m getting from this is not that MTA couldn’t use those tunnels, it’s just that they don’t want to.

    • Alon Levy

      That’s strange… why wouldn’t they want to use those tunnels? There is no additional surface disruption coming from using them, since the stations would have to be done cut-and-cover anyway. If anything, using the tunnels would reduce disruption, because the cut-and-cover stations would be shallower, so construction would be faster.

      • Stephen Smith

        My assumption (which, like everything about NYC’s subway costs, is backed up by very little) is that shallower tunnels would require more cooperation with DEP, ConEd, DOT, etc., and the MTA wants to avoid working with other agencies and companies at all cost.

        • Alon Levy

          …but the stations are cut-and-cover! The work involved in digging shallow tunnels is a strict subset of the work involved in digging deep ones!

      • orulz

        The worse these costs get, the more I’m convinced that the only plausible explanation is that the conspiracy theorists are right: the contractors designing and building this thing are colluding to make it as expensive as possible.

        Put on your tinfoil hats, everyone…

    • Mrs. T

      The section of tunnel from 99th to 106th Street was one of the tunnel segments built in the 1970’s, and it was incorporated into Phase I for off hour car storage. And I’ve read that the section of tunnel from 110th to 120th Street will be incorporated into Phase II.

  2. A.G.

    So, who’s doing the design contract for Phase II? Specifically, who firm/person is deciding between the shallow/deep-bored options, and in that analysis, what’s the conversation about cost? Before we even get into option trade-offs, it would be important to understand how cost concerns are (or are not) being incentive.

    • Joe

      STV and WSP/PB are the design team for Phase 2, AKRF is completing an update of the environmental review.

  3. The Economist

    I am not sure if you understand the politics and attitudes that prevails in the US and New York in particular. Now that the stations in Phase I were mined even less snobby communities than the Upper East Side will have sufficient number of rich enough people willing to sue and argue that “cut-and-cover” disrupts the community too much. They will demand “mined” construction that the “richer” Upper East Side got. Courts are likely to agree with them unfortunately. While the MTA should try “cut-and-cover” it will likely be forced by the courts to deep mine the stations. The fact that its hand is likely going to be forced does not mean that the MTA should not try though. If what you are reporting is correct they have already given in to the NIMBYs.

    The only way to get “cut-and-cover” back to a useful technique in NYC is if Cuomo gets involved, demands accountability and gets “cut-and-cover” stations finished in 1.5 years each. It could happen. I am not betting on it. But look at the speed they are finishing Phase I — Cuomo is breathing in their necks and they will actually get the thing opened on time even if some final touches are not ready.

    Whether NY accepts the tradeoff of cheaper construction and shorter, but full time disturbance will be tested in shortly. If Cuomo’s third track for the LIRR project does not get derailed and he succeeds in delivering on the promised 9 month start to finish grade-separation for each intersection of the Main Line with the remaining not-separated streets, then look for him and his successors to continue the pattern of making the general public accept more disruptive construction in exchange for shorter construction period. I am no fan of Cuomo, but if he fails we are bound to extreme construction costs with complex and unnecessary engineering (in the case of the Second Avenue Subway, deep cavern stations) under the misguided premise that we are reducing the community disturbance of the project. In most cases that is never true because the increased complexity not only increases the costs, but also the duration of the project and the “total community disturbance” is probably the same, but spread over longer time with lower intensity.

    • Alon Levy

      On the Upper East Side, the stations were built cut-and-cover, with extensive surface disruption. In East Harlem, the plan is to build the stations cut-and-cover, with extensive surface disruption. The only thing that is planned to be mined in phase 2 is the segment under 125th Street, going under the 4/5/6. The only thing that was mined in phase 1 was the tunnels between the stations, tunnels that do not have to be mined in phase 2 because they were built in the 1970s.

      • The Economist

        We might need to agree to disagree on the construction method of the stations. The names of the construction methods are somewhat subjective. 72nd and 86th were dug up through two shafts each with enclosed muck houses on top of each shaft (four total muck houses). In my mind that is “mined”. For those stations everything during constriction had to go in and out through the shafts. The rock above each of the two stations and below the road surface is still there. 96th was “cut-and-cover” — the rock between the station and the road surface was removed. Some backfill might have been done at the 96th station, but the original rock that had been there for centuries is gone.
        I am not claiming that “cut-and-cover” for 72nd and 86th at their current depths would have made construction cheaper. All I am saying is that “cut-and-cover” is a method that is not liked by many who think that deep mining is less disruptive and therefore worth it. It is less disruptive for the surface, but takes much longer and the access locations for the deep mining with their own disruptions linger for much longer time — just ask the people on second avenue how much they liked those muck houses (they liked even less the open pit access envisioned before community complaints forced the MTA to build the muck houses).

        • Alon Levy

          But there was a lot of disruption at 72nd… on one side of Second Avenue the sidewalk was down to 7′, the other side was covered with fences with a narrow walkway between them and the building. Businesses complained, vociferously. (I lived at 72nd and York in 2009-10.)

          • Adirondacker12800

            You want no disturbance ever, move some place with 40 acre zoning. Be sure to get a lot that is almost square and put the house in the middle. Indemnifying the business owners for 18 months or two years is a lot cheaper than hundreds of millions more for a station. Much much cheaper than abandoning existing tunnels.

  4. Riverduckexpress

    This supposed rumor is stupid. Keep in mind the first 1970s tunnel in Harlem (from 99th St to 105th St) is *already* in use as part of Phase 1. The 2nd tunnel (from 110th St to 120th St) is only a few blocks away… it would be very hard to not use it when the first tunnel is being used.

  5. The Economist

    There is an undesirable, but very obvious way to cut costs: eliminate 116th street station and move the 106th street station to between 106th and 110th (as far north as possible). While convenient, the 9-10 block spacing for the stations is not a must and up to 12-13 is tolerable in my opinion. That removes one of the big moneypits (the stations), does not lead to demolition of previously built usable infrastructure and cuts the cost per mile or whatever other measure is used. Now I get is why the community wanted a station at 116th, but at the current costs we are either going to need the community around the station to accept upzoning to everything around it with resulting tax revenues covering at least part of the cost of the station, or they will have to walk further to get to a station. The MTA can promise them a station as close as possible but beyond 120th on 2nd Ave if the line ever goes to the Bronx (not on the segment curving to 125th street). Here, I just cut the cost of this monster project down from $6B to $4B ( approximately). I suspect that is what the MTA will do with the new updated EIS for phase 2 anyway. Anyone willing to make the argument that 116th station is worth the $1.5 billion?

    • Alon Levy

      That doesn’t actually save any money. The platforms still have to be built either way, and so do the tunnels in between the already-completed segments. With cut-and-cover, stations don’t cost much more than the tunnels.

      • The Economist

        You are confusing me. Building two stations instead of three obviously saves money. You obviously cannot do “cut-and-cover” for 125th. The other station at, let’s call it 108th, will be cut and cover just because the tunnels on both sides are from the seventies and are “shallow”. The unfortunate moneypit is the TBM box somewhere between 120th and 123rd. That would have to be dug up “cut-and-cover” to get the TBM in the ground, but then they won’t be able to use it as a station the way they did with 96th. The only other thing that this hole in the ground will help with is the bellmouth for future extension to the Bronx that my grandkids’ kids might one day use. The station on that Bronx extension would be somewhere between 123rd and 126th (can’t go further north into the East River).

        • Ryan

          If you want the Second Avenue Subway to ever run to the Bronx, that time is right now.

          Going to the Bronx and going west up 125th are mutually exclusive propositions; nobody is going to build a tunnel that cannot be filled and nobody is going to accept frequency cutbacks to major crosstown transfer points. The second trains start running to Lexington Avenue, you can kiss the Bronx extension plans goodbye as they’ll all become dead on arrival.

          Luckily, with the 125th Crosstown section being a nightmarish money pit that makes no sense on its own merits, we can pretty easily avert some part of this catastrophe by immediately cutting Phase 2 back to a terminal at Triboro Plaza with the 106 and 116 St stations similarly consolidated into a 108 (well, I’d call it 110 but both streets will have exits anyway) St Station. Then, we can either push through to the Bronx right now; or we can call Phase 3 “Phase 3A” and the Bronx extension “Phase 3B” and we can start expanding the tunnel in both directions at the same time after the line opens as far as Triboro.

          This also means the 125 St crosstown can eventually be built in useful capacity as a straight replacement for the M60, going directly from Harlem to Laguardia and perhaps to points further east. (I’d argue 86 is a more important crosstown tunnel than 125, but whichever one gets done becomes the more useful one, right?)

          • Ed

            I agree with Ryan and thought of this too.

            It has always made more sense for any Second Avenue line to go to the Bronx, after which there are options. It can connect to the existing B/D, 5, or 6 lines and provide an additional train on those lines, and alleviate the funneling of Bronx commuters into the 4/5, and this can probably be done relatively cheaply (compared to other MTA projects). Or eventually it can be extended to a cross-Bronx line. But either option augments service more than cutting across 125th Street.

            In addition, there is a case for line running across 125th Street, but any trains really should cross the East River at Randall’s Island into Queens, heading to Laguardia, eventually connecting to the existing Queens lines afterwards. I realize Astoria is a horrible den of NIBYISM, but the line could run along the East River to get to La Guardia, so no els in Astoria.

            Its not that we get either of these by having the 2nd Avenue subway turn onto 125th Street, but doing so forecloses these options for a very limited increase in service. The rationale for doing so was that much of the infrastructure such as the tunnels already was there. If the MTA won’t use the existing infrastructure, the rationale disappears completely. Skip Phase III and see if you can’t move on to either Phase IV or extending the thing to the Bronx.

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  8. Johnathan Boev

    Hello Alon,

    Happy Hanukkah,

    After some recent events in my life I found myself working volunteerly to improve the New York City Transit. I have created this:

    It is piece of work, so…yesterday I was searching the internet and ran across your blog.
    I found your writing is very interesting, you incorporate a lot of detail and back up your information strongly.
    I know that we do not know each other, but I would like to create a possibility to collaborate together creating better public transit thru re-planning and upgrading the transit policies.

    Please let me know and…

    חג אורים שמח

  9. smartone

    I think there are two things at play – Cost and SPEED.
    Cut and Cover would not be a huge issue if the speed of construction was faster.
    when MTA has mission critical construction like Montague Tubes for Sandy Repair – this construction came in UNDER BUDGET and done in LESS TIME than originally predicted.

    So not only should MTA be looking at what went wrong in Second Avenue Subway Phase 1 but also looking at what they did right when Sandy Repairs happened

  10. Editor

    Thank you for this excellent piece. I would though like to make a few comments.

    1. I disagree with one of your financial calculations.

    In your piece, you say – “Phase 1, … , is projected to get 200,000 [riders/day], for a projection of around $25,000 per weekday rider, which isn’t terrible…” To arrive at this number I assume that your math looked like this: $5 B / 200,000 riders = $ 25,000.

    This is not a financially accurate way to present the capital cost/rider of Phase 1 because you have only calculated the cost over a period of one year. My understanding is that the design for Phase 1 assumes a useful life of 100 years. So if one were to spread this cost over 100 years, and assume that the ridership holds steady at 200,000 rider/year, then the per rider cost over the lifetime of the project comes to “only” $ 2,500/year, which to me seems reasonable.

    2. Phase 1 of the project used a section of pre-existing tunnel (built during the 1970s) between 99th Street and 105th Street on Second Avenue. The tunnel was fully renovated, without opening the street above it (for the most part), and will be used on Day 1. Another pre-existing tunnel, between 108th and 115th will surely receive the same treatment if/when Phase 2 is built. More problematic are the two pre-existing stations shells (again from the 1970s) at 106th and 118th street that most likely will need to be gutted and re-built basically from scratch. The jumbo cost will be the 125th street station which will cost well over $1 B and maybe as much as $2 B since it will be multiple levels deep, and will be built under an active subway line, Metro North, and the many historic buildings that exist on 125th Street.

    3. The number 1, 2, and 3 costs items for Phase 1 were: Stations – $ 1.28 B / Professional Services – $ 1.19 B / Guideway and Track – $ 622 M.
    The MTA contracted out most of the professional design and oversight of Phase 1. One would think that they could bring this cost down (a lot) by bringing “in house” much of this work when they move on to Phase 2.
    See page 8 of the MTA’s 2Q2016 SAS Quarterly Report:

    • Jacob Hensel

      Editor, capital cost divided by passengers per day is just a quick comparison ratio. Don’t read too much into it or your own suggestion to divide capital cost by service life in year by passengers per day. Neither of these are sound calculations cause you’ve left out O&M costs, inflation, interest/discount rates, and the fact that most passengers are going to use a lot more of the subway system than just Phase 1 of SAS.

      I actually doubt a full blown cost-benefit analysis was required for Phase 2 because had it been done and seen the light of day I have a hard time believing we’d even be discussing Phase 2 as a possibility right now.

      So what’s the bigger point? Well, if you can own and operate a car for $9,000 annually then public infrastructure better cost the public a good deal less than that per capita and the public infrastructure better be robust enough to displace the need for that $9,000 automobile expense.** As the author suggested put in bike lanes, express bus lane, build more stuff closer to existing stations…Just don’t blow $6 billion plus annual O&M costs to move the population equivalent to Ann Arbor a couple more kilometers each day.


  11. Dracula

    Whoever wrote this trash is an imbecile and thankfully is not in charge of transportation. Filthy ignorant liberal.

  12. Dracula

    “the many historic buildings that exist on 125th Street.” You have not been to 125 Street have you?

  13. Guest

    Run the SAS to the Bronx with stations at Alexander Ave/E 138th St and Third Ave/E 149th St.

    Metro North customers could jump on the subway at the coming Hunts Point station.

    It would be so much cheaper to convert E 125th St into a BRT route in the short term. The bridges are bottlenecks into the Bronx and riders would be more likely to jump on the SAS upstream.

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  15. Elsie's friend

    Saying that the tunnels built during the 1970’s will not be incorporated into Phase II makes no sense. Of the 3 tunnel segments built in the 1970’s, the one between 99th and 105th Streets has already been incorporated into Phase I. And it has been declared that the segment from 110th to 120th Streets will be made part of Phase II. Fact checking is important for credibility.

    • Alon Levy

      I’ve heard second-hand rumors that the 110th-120th segment cannot actually be used because there was an engineering screwup.

  16. ALAMOOPA13


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