NYTIP – enhancing the nyc subway, part 2: south brooklyn

UPDATE (10.28.2020): Post updated with modified recommendations for South Brooklyn de-interlining.

In my last post, I discussed the Central Park West de-interlining. Continuing with point 1 of my three-point plan to improve the NYC Subway (enhance), I’ll address the B, D, N, Q, and R lines in Brooklyn.

Note: Click any image to enlarge.

[Fig. 1] Snippet of the NYC Subway map showing the South Brooklyn subway lines and their branches to Manhattan.

As the map above shows, many subway lines serve South Brooklyn. NYTIP addresses the B, D, N, Q, and R lines due to their complex interaction throughout the borough. Starting from Manhattan:

  • From the 6th Avenue express tracks, the B and D cross the Manhattan Bridge together on the north side and split in Brooklyn; the B serves the Brighton Line and the D serves the 4th Avenue trunk line.
  • From the Broadway express tracks, the N and Q cross the Manhattan Bridge together on the south side and split in Brooklyn; the N serves the 4th Avenue trunk line and the Q serves the Brighton Line.
  • From the Broadway local tracks, the R enters Brooklyn via the Montague Street tunnel and serves the 4th Avenue trunk line.

On the Brighton Line, the B runs express and the Q runs local. On 4th Avenue, the D and N run express and the R runs local.

As you can see, there is a lot of interlining here, which causes a lot of problems. The main culprit is the so-called Gold Street interlocking, which controls the set of switches north of DeKalb Avenue station:

[Fig. 2] Snippet of the NYC Subway track map from vanshnookenraggen showing the complex set of switches and junctions north of DeKalb Avenue.

This interlocking causes a lot of delays for B, D, N, Q, and R riders in Brooklyn – but it doesn’t have to. That’s where NYTIP comes in.

As with Central Park West, NYTIP prescribes service changes that simplify train movements in all of South Brooklyn, improving regularity on the B, D, N, Q, and R lines. The key is eliminating merging conflicts at the Gold Street interlocking.

Option 1: Swap the D and Q lines in Brooklyn

[Fig. 3] D/Q swap, northern segment, via Brand New Subway.

[Fig. 4] D/Q swap, southern segment.

[Fig. 5] Modified track map showing Gold Street interlocking after the D/Q swap, which eliminates all merging conflicts.

Through this swap, the D replaces the Q as the Brighton local to Coney Island, while the Q replaces the D as the 4th Avenue express to Coney Island via the West End line. Under NYTIP, the Broadway and 6th Avenue lines no longer conflict with each other, improving regularity throughout South Brooklyn.

Implications for DeKalb Avenue and Atlantic Avenue

At DeKalb Avenue, the D/Q swap essentially exchanges direct service to Canal Street and Broadway for direct service to Grand Street and 6th Avenue. The station retains direct service to Broadway via the R line, albeit through Lower Manhattan. Brighton riders desiring Broadway service can make a cross-platform transfer at DeKalb Avenue for the R, or make the longer transfer at Atlantic Avenue for the N/Q/R.

Option 2: Swap the B and N lines

[Fig. 6] Overview of the B/N swap.

[Fig. 7] Modified track map showing Gold Street interlocking after the B/N swap, which also eliminates all merging conflicts.

In this scenario, the B replaces the N as the 4th Avenue express to Coney Island via Sea Beach, and the N replaces the B as the Brighton express to Brighton Beach. The B/N swap also removes conflicts between the Broadway and 6th Avenue lines in Brooklyn.

Back in 2004, the MTA surveyed Brighton Line riders about their travel preferences and they picked Broadway over 6th Avenue by a near 2-to-1 ratio. If most Brighton Line riders still prefer Broadway today, then the B/N swap works in their favor. Of course, one must weigh this against 4th Avenue/Sea Beach riders’ preferences.

Implications for DeKalb Avenue and Atlantic Avenue

Under this option, DeKalb Avenue essentially becomes an express stop on the Broadway trunk serving N, Q, and R trains; however, it loses direct access to 6th Avenue. At Atlantic Avenue – Barclays Center, Brighton riders desiring 6th Avenue service must make the long transfer since there is no cross-platform opportunity.

A third option?

About 10 months after I first published this post, I wrote a follow-up post with additional commentary. The post explores de-interlining scenarios for South Brooklyn in the absence of a new yard in Astoria for R trains. I updated it after vanshnookenraggen blogged about South Brooklyn de-interlining using an existing switch provision – a provision I completely overlooked when I first drafted this post.

Utilizing that provision leads to 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, all lines have direct access to at least one storage yard under this option. As such, I think this is the best option, especially given the potential for future expansion. As one example, consider the Staten Island Subway proposals. One proposal connects to Staten Island using existing provisions south of 59th Street station in Brooklyn, while another calls for extending the Bay Ridge line from its present 95th Street terminus to Staten Island. In either case, extending an express train makes the most sense, given how far Staten Island is from the rest of the city. Vansh’s “one switch” plan is certainly one way to catalyze such an extension. I’ll explore these extension options in a future post.

Now, I’d like to circle back to the Brighton line. Due to the track layout, express trains terminate at Brighton Beach, while local trains continue to Coney Island. This could cause unbalanced ridership.

Originally, the Brighton express tracks continued to Coney Island, while the Brighton local tracks took ramps to the lower level at West 8th Street – NY Aquarium station. The Culver line connection to Coney Island severed the lower level connection; the ramps still exist but are trackless. Though reactivating the ramps isn’t desirable due to the resulting at-grade merge, there is another way to rectify this problem.

Potential capital investment: Construct a flying crossover between Sheepshead Bay and Brighton Beach stations.

[Fig. 8] Overview of the Brighton crossover.

This flying crossover allows Q local trains to terminate at Brighton Beach and N express trains to continue to Coney Island, balancing ridership. It would also make the Brighton express service more attractive. Note that this crossover isn’t necessary for de-interlining; as such, this is an optional investment under NYTIP.

Recommended path forward: Option 3 (Vansh plan). This is a change from my previous recommendation (D/Q swap). This option achieves the desired de-interlining, preserves transfers between the Broadway and 6th Avenue services, and is amenable to future expansion.

In my next post, I’ll address the Broadway and Queens Boulevard trunk lines. Until next time!

2 thoughts on “NYTIP – enhancing the nyc subway, part 2: south brooklyn

  1. To me DeKalb de-interlining seems like a no-brainer. It is also helpful to realize that through most of Midtown the 6 Ave trains and the Broadway trains are only about an avenue apart, so for most people there is minimal additional walking if they have to trade a 6 Ave train for a Broadway train or vice versa.

    The only areas where it does make a difference is for the part of Manhattan between Canal and 14th. Here, a new transfer opportunity between the Prince Street BMT station on the Broadway line and the Broadway-Laffayette station on the 6 Ave line would allow for some additional flexibility as well.

    Liked by 1 person

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