Quick Note on Transit Expansion and Development

I’ve been thinking a lot about where subway extensions can go in New York. One of the appendices we’re likely to include down the line in the Transit Costs Project is a proposal for what New York could do if its construction costs were more reasonable, and this means having to think about plausible extensions. Leaving aside regional rail and systematic investments for now, this may roughly be it:

The full-size image (warning: 52 MB) can be found here.

The costs depicted are about twice as high as what I wrote in 2019 with Nordic costs as the baseline, because nominal Nordic costs have doubled since then, partly due to updating price levels from the early 2010s to the early 2020s, but mostly because of the real cost explosion in the Nordic countries. These costs are about $200 million/km in outlying areas, $300 million/km in Manhattan or across water, somewhat less than $100 million/km above ground or in an open trench, and higher than $300 million/km when reconstruction of existing tunnel complexes is proposed; everything is rounded to the nearest $100 million, which creates some rounding artifacts for short extensions that cancel one another out.

But the precise map is not what I think is the most interesting. The point is to build to the frontier of the cost per rider that is acceptable in American cities today, so by definition the marginal line for inclusion on the map, such as the D extension to Gun Hill Road to meet with the 2 train, is also socioeconomically marginal. What I think is more interesting is how important transit-oriented development is for the prospects of lines beyond the most obvious ones (Second Avenue Subway Phase 2, 125th Street, Utica, Nostrand, IBX, and maybe also the 7 to College Point).

The current land use in New York is largely frozen from the middle of the 20th century; the 1961 zoning law was the watershed. Since then, change has been slow, in contrast with rapid redevelopment in places that have chosen a pro-growth path. If the pace of change stays slow, then fewer lines are viable; if the city instead chooses not to keep anti-developmental neighborhood interests in the loop, then more are.

This, in turn, feeds into growth plans. Nordic and Italian planning bundles the question of where the regional housing growth goes with where the subway goes. (Our other positive case study, Turkey, works differently; the answer to both questions is “everywhere.”) This means that subway service goes to areas where substantial quantities of transit-oriented development will be permitted and built, often in negotiations with NIMBY municipalities that would rather just get the infrastructure without the housing; in Stockholm the scale involved is tens of thousands of units per tranche of Nya Tunnelbanan.

In the case of New York, this affects the shape of the map above more than anything. The 6 extension to Coop City is likely good either way, but the other radial extensions in the Bronx are more questionable and depend on where new housing in the borough will be built. The same is true in Queens: more housing in Northeast Queens may argue even in favor of further lines not depicted on the map, for example extending the 7 even further.


  1. df1982

    I feel like you’re stretching the definition of “plausible” with some of those ideas, e.g. the lines out to northern NJ, or the super express through Central Park. And even if it is technically possible I could see the PATH-6 merger as ending up being a world of pain (re-aligning the tracks through the WTC terminal can’t be easy) for little benefit, since NJ commuters can get uptown via the other PATH branch.

    Isn’t it better to put the focus on the clear priorities that already have a bit of momentum behind them, like Nostrand, Utica, N to LaGuardia, IBX (continuing into the Bronx) and Queenslink, and then maybe throw in a couple of modest extra ideas, like Gateway Centre and Co-Op City?

    Similarly, I don’t mind the principle of the Canarsie extension, but it could probably be done for a tenth the cost as a light rail shuttle running up and down Rockaway Pkwy with timed connections for the L train, similar to what was in place before.

  2. adirondacker12800

    for example extending the 7 even further.
    Just because, in a 19th century fit of railroad mania, someone thought the Flushing and Westchester Railroad was a good idea doesn’t mean it ever was or will be. There are more people south of Flushing and most of the former ROW to Hempstead, west of the city line, is park.

    • Alon Levy

      It’s not an imitation of the Flushing and Westchester, it’s a subway vaguely along the line of the Whitestone Branch, which was upgraded and electrified in the 1910s and only taken down in the 1930s because drivers hated waiting at grade crossings.

      • adirondacker12800

        The Whitestone Branch was the Flushing and Westchester. It’s how the LIRR got stuck with it. That doesn’t change that there are more people south of Flushing and likely always will be. And a ROW that is mostly parkland not somebody’s house.

          • adirondacker12800

            The crayon scrawl goes to Whitestone not Glen Oaks. Most of the ROW out to the city line, going south from Flushing, is park. It can be dug up cheap. And there will always be more people that way if for any other reason, the route is longer. Going either way is questionable because those pesky pesky people west of Flushing are already using it.

  3. Frederick

    1. Currently, PATH has commuter railroad status because they are using NEC right of way between Newark and Journal Square. Maybe if we can build a separate tunnel for that segment, PATH can get rid of its commuter rail status, thus allowing full interoperation with the subway.

    2. I humbly suggest a cross-Bronx train through Fordham and Pelham Parkway. Bx12 is one of the most popular bus routes in NYC.

    3. Instead of choosing between Whitestone and Main Street, why not both? The popular Q20/Q44 can be replaced by a subway line. In the (far) future, we can extend further past Whitestone and connect with the Bronx, probably at Pelham Parkway (see point 2 above).

    4. In light of the popularity of Q58, the Queenslink proposal should be made more elaborate, complemented by an extension of M.

    5. One problem about extending the subway past Flushing or Jamaica is that trips from these terminal stations to Manhattan are pretty slow already. Of course, fast trips from Manhattan to Flushing/Jamaica should be the job of LIRR, but we all know how garbage the LIRR is. Maybe we should transfer control of the Atlantic Branch and Main Line (from Sunnyside to Jamaica) to the subway, allowing “super-express lines” (to borrow Program for Action terminology), only leaving the Montauk Branch for the LIRR to access Penn station.

    • Alon Levy

      1. PATH is legally a commuter railway for historic reasons only, and operates under so many waivers it might as well be a subway. Other rapid transit systems that are not legally commuter rail operate in the same ROW with mainline rail in the US, for example the Boston Green Line now that GLX is open.

      2-3. That’s a really good tramway – in general, these routes that don’t make great radial extensions or circumferentials (like IBX/Triboro) are good trams. Same thing for Main Street in Queens.

      4. My Queenslink crayon is just vanilla Queenslink except with a tunnel in the north to permit it to extend QB local instead of branching; I don’t think the bypassed parts of the ROW are that critical. Woodhaven in general is a good tram corridor too…

      5. Regional rail should be useful for city residents too, and one of the reasons my subway crayon looks the way it does is that a bunch of areas are already handled by regional rail (link, with the usual 52 MB warning). The subway can be to some extent sped up, and even now, the main problem with speed is transfers and walk and wait times – even an all-local trip like my current Queensbridge-Jay Street commute is okay when I don’t have to wait 10 minutes for the F.

      • adirondacker12800

        PATH has had separate tracks since the PRR closed the Jersey City ferry terminal in 1967. PATH tracks don’t point at the 6 train, they point at the 1. The downtown terminal, in all it’s iterations, has been a loop. The platforms are oriented north/south.

      • Attlee

        Do you think the New York subway could be sped up so that the express trains were as fast as the Victoria line in London say?

      • xh

        “Other rapid transit systems that are not legally commuter rail operate in the same ROW with mainline rail in the US, for example the Boston Green Line now that GLX is open.”

        PATH is special because it shares with NEC not only the ROW, but also the Dock Lift Bridge. PATH’s CBTC signalling is tied into NEC’s Dock interlocking that interlocks the movement of the Dock Bridge.

  4. marvin gruza

    A line over the LIE out to marathon parkway would serve north east queens

    The Fulton St IND could make use of its 4 tracks if an east river tunnel was dug and if an elevated line was run over Conduit Blvd from pitkin ave to a reconnection with the rockaway branch – The express tracks would/could have 8 tph to far rockaway +8tph to rockaway park + 8 tph into kennedy airport leaving the local tracks fully not interlined

    • Alon Levy

      8 tph overserves Rockaway Park – I’m not sure what the Riders’ Alliance’s #6MinuteService campaign says about it but my conception is that the A train gets six-minute service and thus each of the two branches gets 12-minute service and Rockaway Park stays a shuttle. This is not a high-density area and it’s far from the core so it’s about the last place you’d want to place residential TOD in. Even with the depicted Queenslink, it’s just 5 off-peak tph per branch and that’s via a faster connection to Midtown jobs.

      The reality is that this area is hard to serve in terms of both built form (it’s low-density) and the rail network (it’s really awkward because of the combo of the historic LIRR line and the Rockaway Cutoff).

      • adirondacker12800

        the last place you’d want to place residential TOD in.
        They didn’t ask you. They went and built it anyway.

      • dma446

        Are there any specific advantages to running Queenslink to Rockaway and maybe having As turn at Howard Beach than vice versa (A stays at Rockaway and Queenslink stops at HB)?

        Also, is 8 Ave express service still doing Queens Blvd to Fulton like in your deinterlined map? Kinda bothers me how circular it is on a map…

        • Alon Levy

          I think the Rockaways would prefer the faster route into Midtown, which is Queenslink. But in terms of operation, there’s no real difference.

          And yeah, the map aims for local coherence and also (as a small bonus) consistent local-express patterns throughout the route, but as a result, the routes’ overall structure gets kind of drunk, with that Jamaica-to-Jamaica A/E and the Rockaways-Forest Hills-Manhattan-Coney Island F/M.

          • dma446

            I see. I do like how Queenslink allows Rockaway riders choice between expresses to Brooklyn/Downtown Manhattan and expresses to LIC/Midtown which just one transfer for everyone. The amount of TPH probably overserves us but I’m not complaining.

            One idea I had under your deinterline map of current service was to do a W4 switcharoo and have F/Ms terminate at WTC and E to Culver. Would ruin your consistent local-express patterns though.

    • Eric2

      Not really. There is market demand to build densely even with elevated rail. What’s limiting development is zoning.

  5. ChetNYC

    Would extending the IBX to Staten Island be a better idea that extending the R train?

    • Alon Levy

      No. Circumferential lines should stay circumferential; extending them outward as radials is bad, and the experience of the historic G when it went to Forest Hills is one example of why (link).

      • Ben She

        Isn’t the radial direction represented by the regional rail tunnel to Fulton Center continuing to SIR, so by connecting IBX to St. George from the east, it’s no less innocuous than hitting Jackson Heights or Broadway Junction?

      • adirondacker12800

        The GG wasn’t circumferential, it was two radials connected by a third radial. They didn’t build the “Second System” and there have been compromises.

  6. Nick W

    Is the Jersey City subway a tunnel for the HBLR or is it an extension of the 7? It’s the same color as the 7.

    Any reason why the existing light rail North of Hoboken Terminal was killed in this plan?

    • Alon Levy

      It’s an extension of the 7, taking over some PATH tunnels and the HBLR rights-of-way. Likewise, another HBLR right-of-way is taken over for the subway extension from 50th.

      • adirondacker12800

        Once you figure out the Heisenberg compensators for the devices that warp the space time continuum to have two trains in the same place at the same time.

      • wood344

        Are the HBLR extensions to Newark and Staten Island then actually also 7 extensions or do they now only go to Liberty State park and need to transfer there? If it’s the latter then how much more would it cost to keep more of the existing light rail?

        You’re eliminate from Port Imperial to Liberty State Park from the light rail just to use the ROW of the section from Hoboken Terminal to Harsimus Cove. The light rail is at grade with street crossings from Newport to Harsimus Cove which I’m assuming won’t work for the 7. So whether the 7 is underground or elevated why not keep the light rail there above or below it?

        For Newport to Hoboken Terminal how quickly can the 7 transition from being underground coming into Hoboken Terminal (and not just right below the surface but all the way under the path?) and then rising to get on the light rail’s elevated ROW? Is it going to take a significant chuck of the way to Newport to even use the elevated tracks that stop being usable at Newport?

  7. Herbert

    Even a CSU mayor (!) In Nuremberg touts “we’ll build housing and the subway at the same time” as a positive of the (otherwise questionable) U3 southwest extension into an area currently literally known as “Tiefes Feld” (“deep field”) so it’s fair to say the paradigm is (at least in rhetoric) mainstream in Germany by now…

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