UPDATE (09.13.2021): New image added. In a previous update, I substantially revised this post for clarity.
Welcome back to my ongoing NYTIP series! In my last post, I discussed the Eastern Parkway trunk line in Brooklyn served by the 2, 3, 4, and 5 lines. In this post, I will discuss the 2, 3, 4, and 5 lines in Upper Manhattan and The Bronx, and explain why de-interlining is extremely challenging.
If you’ve read the preceding posts in this series, you’ve seen that the key to enhancing the NYC Subway (point one in my three-point plan) is eliminating merging conflicts between subway lines – mostly through de-interlining. In some cases, de-interlining is trivial since it does not require capital investment; in other cases, it only works with capital investment.
With the IRT lines in The Bronx, it’s a bit of both – and all options have their share of difficulties. Let’s explore.
Note: Click any image to enlarge.
[Fig. 1] Snippet of the NYC Subway Map showing current service in The Bronx.
The circled areas in Figure 1 above are the “trouble spots” of the Bronx IRT system – and the keys to determining the efficacy of any de-interlining option. Let’s take a closer look.
[Fig. 2] Track map of the 2, 3, 4, and 5 lines with emphasis on the South Bronx and Harlem. Source: vanshnookenraggen.
The first trouble spot is the 142nd Street junction on the 2 and 3 lines, a flat junction that constrains capacity on both lines. The second trouble spot is the 149th Street junction where the 2 and 5 trains meet; as Figure 2 shows, 5 trains negotiate a wicked S-curve between 138th Street and 149th Street. The sharpness of the curve restricts the 5 train’s speed, inducing delays.
[Fig. 3] Snippet of vanshnookenraggen’s track map showing the East 180th Street station and additional conflicts.
The last trouble spot is East 180th Street. During peak hours, 5 express trains from the Dyre Avenue branch entering or leaving the center track at East 180th Street must cross the local tracks at grade. The branched 5 service between Nereid Avenue and Dyre Avenue also contributes to delays and, for Dyre Avenue branch riders, infrequent service. While recent improvements allow some trains to use modified yard leads to avoid choke points, merging issues remain.
There are several ways to resolve these issues.
Option 1a: Full de-interlining using existing tracks
[Fig. 4] Overview of Option 1a. Created using Brand New Subway.
Option 1a fully de-interlines the Bronx IRT. Under Option 1a, the 3 replaces the 5 to Eastchester – Dyre Avenue and runs local in The Bronx. The 2 runs express in the peak direction from East 180th Street to 3rd Avenue – 149th Street. As an optional enhancement, peak-direction 2 express service can run beyond peak hours on weekdays similar to the peak-direction 6 and 7 express services. The 5 runs via Jerome Avenue and can terminate at one of the following five locations thanks to the Jerome Avenue el’s switch layout: 149th Street – Grand Concourse, 167th Street, Burnside Avenue, Kingsbridge Road, and Bedford Park Boulevard. Option 1a contemplates one of the latter three locations for 5 service. (Woodlawn’s switch layout does not lend itself to high-frequency operation, so it is not an option.) The figure below shows conceptual 5 service to Burnside Avenue or Kingsbridge Road:
[Fig. 5] Conceptual service patterns for the 5 via Jerome Avenue.
One potential difficulty with these patterns, given that both 4 and 5 trains run frequently, is delays caused by trains crossing in front of each other. Due to switch locations, terminating 5 trains must discharge their passengers regardless of where they turn on Jerome Avenue. One way to mitigate this issue is building two new switches near Burnside Avenue:
[Fig. 6] Conceptual diagram of new switches at Burnside Avenue for operational flexibility.
This would make Burnside Avenue similar to Parkchester on the 6 line. However, as is the case with Parkchester, 4 and 5 trains still cross in front of each other. An alternative capital solution exists to avoid this issue.
Potential capital investment: Reconfigure Bedford Park Boulevard station to simplify terminal operations.
[Fig. 7] Overview of the Bedford Park Boulevard improvement.
This optional improvement, which contemplates island platforms at Bedford Park Boulevard, obviates the need for new switches at Burnside Avenue. The new platforms would be slightly south of the current platforms to allow for new switches. This conversion takes advantage of the space on the left side of the ROW near Concourse Yard. Consequently, the northbound local track retains its existing alignment.
[Fig. 8] Detailed look at the Bedford Park Boulevard improvement.
This investment includes a new switch north of Kingsbridge Road station, which allows northbound trains on the center track to access Jerome Yard without wrong-railing. It also includes provisions for exits to a decked-over Concourse Yard, possibly replacing gas stations with pedestrian plazas or other sustainable uses, and grade separation of the Jerome Yard leads – a feat accomplished by elevating the southbound local and center tracks. This requires grades in excess of the 3% standard due to space constraints – about 3.7% (1 in 27) from the Bedford Park Boulevard switches to the apex (about 20 feet above the existing ROW), and 3.33% (1 in 30) from the apex back to the ROW, just south of an existing switch. However, the subway regularly traverses steeper grades, so this should be feasible.
In this scenario, 4 trains run to Woodlawn and 5 trains run to Bedford Park Boulevard. The 5 uses the Jerome Yard leads to change directions, ensuring no conflicts with the 4. This allows two possible operating patterns – doubled local service at all Jerome Avenue stations up to Bedford Park Boulevard, or reinstating peak-direction 4 express service. In a previous MTA pilot program, select 4 trains ran express from Bedford Park Boulevard to 125th Street with intermediate stops at Burnside Avenue and 149th Street – Grand Concourse. There were two key issues with the pilot, however. The first issue was less service at local stops – a problem that the 5 via Jerome Avenue resolves. The other issue was express trains skipping busy stations like Fordham Road and 161st Street – Yankee Stadium – the latter being The Bronx’s busiest. A capital solution to the latter issue exists.
Potential capital investment: Convert Fordham Road and the upper level of 161st Street – Yankee Stadium to express stops.
[Figs. 9, 10] Overview of the Fordham Road and 161st Street express stop conversions.
While 161st Street is the busiest station in The Bronx, it is Fordham Road that would make the Jerome Avenue express service viable. To gain maximal benefit from the express, it must attain sufficient ridership from the northernmost stations to leave room on the locals for passengers at the southernmost stations. Thus, if I had to choose one of these two conversions, I’d choose Fordham Road.
While Option 1a has some benefits, it also has three major issues. The first issue is that it leaves the 6 train as the only direct route to Manhattan’s east side from anywhere in the South or East Bronx. Under Option 1a, 2/3 riders would have to transfer at 149th Street – Grand Concourse to the 4/5. As the 149th Street – Grand Concourse station complex only has a few narrow connecting passages between platforms, it would need a major rebuild to handle large volumes of transferees. The second is conflicts between 4 and 5 trains on Jerome Avenue, which also require capital investments to resolve as noted above. The third is a massive service cut to Harlem. If the 2 and 3 both serve The Bronx, there is no longer any service to the 145th Street or Harlem – 148th Street stations on the current 3 line. Options exist to mitigate the latter issue – I present two such options below.
Option 1b: Implement Option 1a with an infill station at 145th Street
[Fig. 11] Overview of Option 1b with the new 145th Street station.
[Fig. 12] Option 1b track map. Note the eliminated conflict near 149th Street – Grand Concourse.
Option 1b contemplates a new, full-length infill station under the Col. Charles Young playground serving 145th Street, with entrances at 143rd Street/Malcolm X Boulevard, 145th Street near the 145th Street Bridge, and possibly 145th Street/Malcolm X Boulevard. 2 and 3 trains would run together to serve the new station and enter The Bronx. Owing to the Lenox Yard, the Harlem – 148th Street station would see limited peak-hour 3 service; however, the station would close at other times. This minimizes use of the flat 142nd Street junction, improving regularity on the 2 and 3 lines.
The Harlem Shuttle
On Twitter, vanshnookenraggen proposed a Harlem shuttle between the 148th Street and 135th Street stations, which allows full de-interlining without an infill station or station closures:
It’s an interesting concept. One possible drawback is that transfers to or from the Harlem shuttle require a crossover or crossunder. I think the Harlem shuttle would be a better sell with cross-platform transfers, which requires converting 135th Street station to island platforms. This conversion isn’t simple, however – the existing subway is immediately below street level, and it’s also offset from center on the west side of Malcolm X Boulevard. The silver lining is that both the boulevard and the sidewalks are wide, which could allow such a conversion without property takings.
Potential capital investment: convert the 142nd Street junction to a flying junction.
[Fig. 13] Conceptual grade separation at the 142nd Street junction.
This grade separation removes a key bottleneck on the 2/3 lines and sets the table for a Harlem shuttle with island platforms at 135th Street, as shown in the figure below.
[Fig. 14] Modified Harlem shuttle concept.
Note, however, that this plan would likely be more costly than vanshnookenraggen’s plan.
In any case, is full de-interlining the best option for The Bronx at present? Let’s consider another alternative.
Option 2: Partial de-interlining option – 2/5 swap
[Fig. 15] Overview of Option 2.
[Fig. 16] Option 2 track map showing eliminated conflicts between express and local trains.
Option 2 prescribes a simple swap of the 2 and 5 lines north of East 180th Street. The White Plains Road branch is about 4.5 miles long with 10 stations, while the Dyre Avenue branch is about 4 miles long with 5 stations. Under NYTIP, express services should serve the longer, higher-ridership branches; as such, Option 2 sends the 5 express to Wakefield – 241st Street and the 2 local to Eastchester – Dyre Avenue. With this change, peak-direction 5 express trains no longer cross the local tracks to or from East 180th Street.
Under Option 2, all 2 trains serve the Dyre Avenue branch and all 5 trains serve the White Plains Road branch to allow frequent service on each branch. This does not preclude put-ins from Nereid Avenue, Gun Hill Road, or East 180th Street – if necessary – to maintain regularity. This option could be paired with the grade separation shown in Figure 13 so that 2 and 5 trains in The Bronx run at the same frequency – ideally 30 TPH combined.
Since there is no direct alternative to 5 service in the South or East Bronx at present, and given the capital investments required to solve that problem, full de-interlining should be deferred. Therefore, as of 09.05.2021, I am now leaning on Option 2 for short-term improvement. In the future, investments such as those described above – along with regional rail improvements and a potential Bronx branch of the Second Avenue Subway – could pave the way for full de-interlining of the Bronx IRT with minimal inconvenience.