UPDATE (08.26.2021): Post revised for clarity.
In my last post, I introduced the New York Transportation Improvement Plan (NYTIP). In that post, I outlined a three-point plan for fixing the NYC Subway:
- Enhance (minimize merging conflicts)
- Extend (extend existing lines)
- Expand (build new lines)
I’ll begin my series on point 1 – enhance – with the Central Park West (CPW) trunk line, which serves the A, B, C, and D trains.
Note: Click any image to enlarge.
[Fig. 1] Snippet of the NYC Subway map featuring the CPW trunk line.
The CPW trunk line, as its name implies, runs along the west side of Central Park for most of its length. It serves the west side of Manhattan from 145th Street to 59th Street – Columbus Circle. Two 8th Avenue services from Inwood and Washington Heights (A express and C local) and two 6th Avenue services from The Bronx (B local and D express) serve the trunk. Under the current setup, the A and D run express, and the B and C run local. This setup induces merging conflicts for both local and express services at two points – south of 145th Street and south of 59th Street. Making matters worse, the A, B, C, and D don’t run at the same frequency, increasing the likelihood of delays.
[Figs. 2, 3] Existing merging conflicts on the CPW trunk line. The original track map belongs to vanshnookenraggen.
Now, removing these conflicts isn’t a novel idea. For example, Alon Levy’s de-interlining plan suggests an A/C express and B/D local, while a similar plan reverses this paradigm – A/C local, B/D express. The Regional Plan Association, in their Save our Subways publication, goes even further – RPA’s plan truncates the C to a Brooklyn shuttle to double A express service, while the B and D run via CPW local. There are pros and cons to each of these proposals, though NYTIP does not prescribe anything as drastic as RPA’s plan for CPW.
When I first published this post in early 2019, I recommended swapping the C and D lines as the cheapest way to de-interline CPW. However, I gave more thought to other options. I recall the M-V combo controversy from last decade – MTA originally called this route the V, but riders preferred the historic M designation, and so the latter stuck. If a C/D swap generates a similar controversy, then another alternative would be better.
Thankfully, it’s possible to “de-interline” CPW in a way that allows both Upper Manhattan and The Bronx to retain full-time express service while minimizing potential rider confusion. I will explore two options that achieve this.
Option 1: 8th Avenue service express, 6th Avenue service local
[Figs. 4, 5] Overview of Option 1, illustrated using Brand New Subway.
[Figs. 6, 7] Merging conflicts removed through Option 1.
Option 1 implements a modified version of the original operating pattern. Under Option 1, service is as follows:
- A: CPW/8th Avenue express from Inwood – 207th Street
- B: CPW local/6th Avenue express from Washington Heights – 168th Street
- C: CPW/8th Avenue express from Norwood – 205th Street
- D: CPW local/6th Avenue express from Bedford Park Boulevard
Let’s look at some implications.
C/D Service in The Bronx
Under Option 1, both C and D trains serve The Bronx all day, every day, to encourage ridership. The C runs with full-length (600-foot) trains as opposed to 480-foot trains, though it does not run overnight – the D replaces the C overnight. There is still some interlining between C and D trains since the Concourse line only has three tracks. However, when the C runs express in The Bronx, it does not merge with the D. While the C express would skip the busiest station in The Bronx (161st Street – Yankee Stadium), an opportunity exists to address that issue.
Potential capital investment: Convert 161st Street – Yankee Stadium to an express stop with island platforms.
[Fig. 8] Overview of the 161st Street – Yankee Stadium lower level conversion.
This optional conversion isn’t necessary to de-interline CPW, but it would make the C express service more attractive; 161st Street is a major transfer point between lines serving opposite sides of Manhattan.
To minimize costs, the conversion would preserve as much of the existing station infrastructure as possible. One way to achieve this is realigning the local tracks behind the existing side platforms, removing the side walls, and extending each platform to the center track. The resulting extra-wide island platforms should accommodate crowds with room to spare. Widening existing stairwells and adding new exits at the station’s west end could further improve crowd distribution.
A 4-Track Concourse Line?
Original plans for the Concourse line called for 4 tracks, but funding shortfalls resulted in only three tracks. While 4 tracks are nice to have for maximum de-interlining and ridership potential (and honestly, I love the idea), NYTIP does not contemplate this conversion – yet.
A/C Service in Brooklyn
Option 1 does not affect A/C service in Brooklyn – the A remains express and the C remains local.
8th Avenue Local Service
Under Option 1, the E is the sole 8th Avenue local service. Consequently, one must transfer at 7th Avenue – 53rd Street to the B/D to travel between the 8th Avenue local stops (50th Street, 23rd Street, and Spring Street) and points north of 59th Street. However, this is a cross-platform transfer regardless of direction. 50th Street is an interesting case since the E serves the lower level platforms. What happens to the upper level platforms?
Alternative 1: 50th Street served by E trains only
While this is the simplest option, it results in a de facto closure of the upper level platforms, or conversion to a split mezzanine. Over 6.9 million passengers used this station in 2019, making this option difficult. One possible mitigation strategy is increasing 8th Avenue local service from Queens as part of a Queens Boulevard de-interlining strategy.
Alternative 2: Convert 50th Street to an express stop with switches
The cheapest way to do this is to install switches both north and south of the station, allowing A and/or C express trains to stop there:
[Fig. 9] Snippet of NYC Subway track map with hypothetical switches north and south of 50th Street.
Since the E joins the 8th Avenue trunk immediately south of 50th Street, building the switches on the southbound side may require a northward extension of the southbound platform.
Alternatively, one could extend the 50th Street platforms over the current local tracks so that A and C trains can stop there without switching:
[Fig. 10] Hypothetical platform extensions at 50th Street station.
This conversion is likely more expensive due to column demolition and replacement. Since a 50th Street express stop conversion requires some level of disruption, Alternative 1 is a better fit for Option 1.
Option 2: 8th Avenue service local, 6th Avenue service express
[Figs. 11, 12] Overview of Option 2.
[Figs. 13, 14] Merging conflicts removed through Option 2.
Under Option 2, service is as follows:
- A: CPW/8th Avenue local from Washington Heights – 168th Street
- B: CPW/6th Avenue express from Inwood – 207th Street
- C: CPW/8th Avenue local from Bedford Park Boulevard
- D: CPW/6th Avenue express from Norwood – 205th Street
Let’s look at some implications.
C/D Service in The Bronx
Option 2 prescribes the same improvement to C trains as Option 1 – namely, full-length (600-foot) trains. The C replaces the B as the Concourse local, while there is no change to D service. As with Option 1, C and D trains serve The Bronx all day under Option 2.
8th Avenue Service
Under Option 2, the A and C run local and the E runs express. This prevents congestion and merging delays, while preserving service levels at both local and express stations. The C terminates at World Trade Center station, while the E continues to Brooklyn with the A. Owing to the existing track layout, select E trains can turn at 34th Street – Penn Station or Canal Street in Manhattan to preserve regularity in Queens.
A/E Service in Brooklyn
Previously, I had the A run local in Brooklyn and the E run express to preserve local and express alignments on each line. However, such a change isn’t necessary to de-interline CPW. Therefore, in Brooklyn, the A will remain express and the E will run local instead.
As you can see, both options significantly reduce merging conflicts through the CPW corridor while preserving direct local and express service from both Upper Manhattan and The Bronx. Both options have their pros and cons. A particular advantage of Option 2 over Option 1 is preserved service levels at all stations. However, there are some complications regarding long-term planning.
On 8th Avenue, there are several potential routings for local trains. They can terminate at World Trade Center, serve Brooklyn via Fulton Street, serve Brooklyn via the Culver line, or use the Worth Street subway provision. The express tracks, however, connect only to the Fulton Street corridor in Brooklyn – any other routing requires crossing over the local tracks. For Option 2, since 8th Avenue services from Queens would run express, such lines become circuitous. This is a consideration, but not a “deal-breaker”.
As of 08.26.2021, I am still leaning toward Option 2 for the CPW de-interlining. Option 2 preserves direct local and express service from Upper Manhattan and The Bronx, removes several merging conflicts, and ensures that all affected stations do not lose any service.