NYTIP – enhancing the nyc subway, part 3.5: astoria and south brooklyn

UPDATE (10.23.2020): Post substantially revised with new recommendations.

Welcome back to my ongoing NYTIP series! In the comments section of my post on SAS Phase 2X, commenter mrsman gave some interesting commentary about alternate de-interlining strategies (also see this Reddit thread). It got me thinking about how to handle the Astoria/Broadway and South Brooklyn de-interlining in the absence of a new yard north of Astoria – Ditmars Blvd station. Let’s explore, shall we?

First, let’s recap. For South Brooklyn, de-interlining options include a D/Q swap and a B/N swap. For Astoria and Broadway, de-interlining options include sending all Broadway Express service (N/Q trains) via the Second Avenue Subway and sending all Broadway Local service (R/W) via Astoria. The issue with the latter is yard access – the R would not have direct access to a train yard. I proposed a new yard within the Con Edison property north of Astoria to mitigate this problem and catalyze a potential LaGuardia Airport extension. However, a new yard is a major capital investment. In the absence of said yard, how can we remove the bottleneck in South Brooklyn? Here are some options:

Alternative 1: Reroute R trains via Brighton Local to Coney Island.

This reroute gives the R direct access to the Coney Island Yard. In addition, the 44 stops end-to-end from Astoria – Ditmars Blvd to Coney Island is the same number of stops on the current R from Forest Hills to Bay Ridge – 95th Street. Unfortunately, this results in some interlining on the Brighton line. If you reroute the R this way, how does this affect the proposed South Brooklyn swaps? I will present what I feel are the best options under this scenario:

Alternative 1, option 1: 4th Avenue – B/D express, N local; Brighton – Q express, R local

[Fig. 1] Option 1 track map. Original belongs to vanshnookenraggen.

[Fig. 2] Option 1 route map, via Brand New Subway.

Under Option 1, the Q shifts from local to express on the Brighton Line, terminating at Brighton Beach. The B replaces the N via 4th Avenue express and Sea Beach, and the N replaces the R via 4th Avenue local. This is a modified version of the B/N swap I originally proposed.

EDIT: As pointed out by mrsman in the comments, this option leaves the N without direct yard access – an inherent flaw in this option.

Alternative 1, option 2: 4th Avenue – N/Q express, D local; Brighton – B express, R local

Under Option 2, the Q replaces the D via 4th Avenue express and West End, while the D replaces the R via 4th Avenue local. This is a modified version of the D/Q swap I originally proposed. This option requires one less service change than Option 1.

Under either option, you could retain the W between Astoria and Lower Manhattan to beef up Broadway local service. Since both options untangle the infamous Gold Street interlocking north of DeKalb Avenue station, the recommended option will ultimately depend on ridership preferences.

EDIT: In April, commenter Leo Shirky suggested the following:

Alternative 1, option 3: 4th Avenue – B/D local, Q express; Brighton – N express, R local

On 4th Avenue, Leo suggested B local service to Bay Ridge, D local service via West End to Coney Island, and Q express service via Sea Beach to Coney Island. On Broadway, Leo suggested N/R local service and Q express service. Presumably, the N and R serve Astoria while the Q remains on SAS; the Q train, therefore, does not conflict with any other line, allowing significant service increases.

Now let us consider another alternative, based on vanshnookenraggen’s post on South Brooklyn de-interlining:

Alternative 2: Reroute R trains via West End to Coney Island

[Fig. 3] Overview of Alternative 2.

I commented on Vansh’s post, stating that I generally like the idea. It involves a bit more rearranging than either the D/Q swap or B/N swap, and results in the following service pattern:

  • Brighton line
    • N express to Brighton Beach, Q local to Coney Island
  • 4th Avenue line
    • B express to Bay Ridge (local south of 36th Street)
    • D express to Coney Island via Sea Beach
    • R local to Coney Island via West End

Importantly, this pattern allows future extension of an express train (in this case, the B) to Staten Island. Additional provisions located south of 59th Street, if used, could allow a Broadway local service (say, the W) to run local to 86th Street while the B runs express from there. I’ll discuss these options in a future post.

In the meantime, lets discuss the R on West End. In this scenario, the R does not conflict with any other lines, allowing significant service increases and the possibility of peak express service on West End, Astoria, or both. (Note that NYTIP does not recommend an Astoria peak express unless the line extends to LaGuardia Airport.)

Recommended path forward: Alternative 2. Going beyond the B/N swap originally proposed, Alternative 2 allows immediate service enhancements and could catalyze future expansion.

Look for additional updates on NYTIP in the near future. There’s a lot more to discuss! Until next time!

8 thoughts on “NYTIP – enhancing the nyc subway, part 3.5: astoria and south brooklyn

  1. Thank you for this updated post. You had very succinctly put together our discussion in the comments from a few months ago in a nice post.

    I prefer option 2. Under both options you provide a link for Astoria trains to Coney island yard. But how do Bay ridge trains get to the yard? Under current trackage there is no connection for the Broadway Express to reach a yard at the northern end. It is true that some of your expansion plans will provide a connection Via 125 Street. But until that happens Bay ridge trains need to use the 6th avenue Express to reach the concourse yard.

    again thank you for the update and I look forward to seeing more posts from you in the future.

    Liked by 1 person

    1. You’re welcome! Thanks for reading!

      Now that you mention it, it’s clear I overlooked an inherent flaw in Option 1 – loss of direct yard access for the N. This definitely makes Option 2 preferable.

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  2. Would you consider a B/D 4th Ave Local, Q Express, N/R Brighton alignment? This means there is no underlining in the Flatbush tunnel between 6th Ave and Broadway trains as in option 2 and gives residents in the Sea Beach/West End areas of Brooklyn access to both 6th Ave and Broadway. As you say in your original South Brooklyn post, Brighton residents vastly prefer Broadway service to 6th Ave service. Under this new alignment (Option 3 if you will), the B/D run local along 4th Ave, with the D still serving the West End line to Coney Island, and the B to Bay Ridge. The Q serves Sea Beach and the 4th Ave express. All 4th Ave trains use the bridge, and N/R service from Brighton uses the Montague Tunnel. (A nice side effect of this is that the B preserves the alterations in its terminals: B train to Bay Ridge instead of B train to Brighton Beach). It also removes the need for a W train, and the N/R would both serve Broadway Local while the Q is express.

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    1. I haven’t considered this alignment. Part of it reminds me of RPA’s “Canal Flip” (I’ll be honest – I wasn’t fond of that idea). That said, this is a feasible “Option 3” for SBK de-interlining. I’m assuming you’d match the frequency of Broadway local and express services (e.g. N/R combined 30 TPH, Q 30 TPH)?

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  3. Very nice! I also like Vansh’s deinterlined proposal and think it’s very ingenious. Although, when it comes to a extension to Staten Island, I must ask under this proposal where exactly are the tracks branching off? If it’s off 59 St, then you would have to send a Broadway local to Bay Ridge which takes off trains from the West End (Vansh had said you need at least 18 TPH going there to be time competitive with their current service. The curve around City Hall limits Broadway local service to 20-21 TPH, so unless that’s fixed, Bay Ridge and the West End would be stuck with 10 TPH).

    If it’s off 95 St, then while the distance to Staten Island is shorter, the river crossing it’s more deep. Grasmere is also less dense than St. George and the latter is a big transit area in the most dense part of the island.

    I think the best plan for express service to Staten Island is Alternative 1 with a Broadway express branch off 59 St to St. George. Brighton Beach gets the short end of the stick though with Broadway local service. At the very least, they can transfer at Dekalb Ave for 6 Ave express service.

    Liked by 1 person

    1. I don’t think there’s much to be done about that wicked City Hall S-curve, so any Staten Island extension options will likely have to work around it.

      That curve makes the case for consolidating R/W service into just one (the R) stronger. Southbound, you could fix up City Hall lower and turn some R trains there, just short of that curve. For SI, I envision either sending an existing express service (the B under Vansh’s plan, a Broadway express if you send the N/Q/R via 4th Avenue and the B/D via Brighton), or sending a branch of the full-length SAS to SI. Note that if you use the 95th Street provision, it may still be possible to reach St. George (older plans provisioned for such a connection at Grasmere, with some service heading north to St. George and some service heading south via existing SIR).

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      1. Ah, so like how the A branches to Ozone Park and Rockaway? It could work despite the limited amount of service each branch would get (North Shore would get more as it’s more populated). Alt 1 with the branch from 59 St and service splitting to the North Shore and South Shore would probably be quicker for the North Shore than service coming from 95 St under Alt 2. Service to the South Shore is about even either way time wise and frequency wise.

        If you want to be very bold, do Alt 1, have the 4 Ave local go to Coney Island and the 30 TPH 4 Ave express goes to 95 St and SI with 15 TPH for both the North and South Shore each. I imagine only SI and Bay Ridge would like that option lol (so basically NY-11).

        All that being said, Alt 2 with the B to SI from 95 St and splitting is probably the best option that doesn’t make trips slower for people in Brooklyn. There’s a good amount of bus ridership from SI that goes to that area around Bay Ridge too.

        [nerdy.nel: Your comment posted twice, so I deleted the duplicate.]

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      2. Yes. I think Staten Island is the only place where such branching works. Assuming the NYTIP baseline frequencies of 4 minutes or better during the peak and 8 minutes or better off-peak, that translates to 8 minutes or better on each SI branch at peak and 16 minutes or better off-peak. It’s a major service increase compared to current SIR service. You could even retain the SIR for local service (it’s a long way from St. George to Tottenville!) and let the subway assume the role of peak express.

        That other suggestion is indeed bold, but I don’t think SI warrants all the 4th Avenue express services relative to Coney Island. (Of course, if you send a new line to SI like an SAS branch, that issue becomes moot.)

        Your last paragraph is exactly what I had in mind with Alternative 2. I would’ve liked to use existing provisions to expand 4th Avenue express service to 86th Street, but as you mentioned, the City Hall curve throws a wrench into that plan.

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