I’m visiting New York again, and the subway is noticeably deteriorating in speed and frequency. But it’s not the speed I’d like to discuss (it’s been covered in the media, both by me and by others) – it’s the weekend service changes. With its 24/7 subway service, New York relies on selective closures of line segments on nights and weekends for maintenance. Expressions like “the D is running on the F and the F is running on the D” are well-known to regular subway riders. However, I don’t think the way the MTA is choosing which lines to shut down every weekend is optimal. I wrote about how different subway lines can be used to substitute for each other in Boston last year; this year, I encountered a big change in New York that, while not as destructive as what I saw in Boston in November, was avoidable.

The trip itself was between Central Harlem and Inwood. I’m staying in Harlem near the 2 and 3 trains, and was visiting friends in Inwood near the A. The most direct path would have been to walk to 125th and St. Nicholas to take the A, but this was blocked because the A was not running north of 168th. The second best option would have been to ride the 2 or 3 to 96th and change wrong-way to the 1, but this was also blocked since the 2 and 3 were not running at all on their Harlem trunk line. The route I took was to walk to 125th and St. Nicholas to take the A up to the 1, changing at 168th Street, an inconvenient transfer involving an elevator (the 1 is deep and only elevator-accessible at 168th).

It was not an especially egregious change. The trip took around 45 minutes and was all-rail; without the changes, it would have been about half an hour. In Boston, the subway shutdowns forced me onto multiple buses in mixed traffic, and a trip that should have taken 40 minutes ended up taking maybe an hour and a half. However, the extra transfer penalty and the difficulty of finding a good all-rail route are real.

In the post about Boston, I argued that even in relatively sparse rail networks, like Boston’s, rail lines are redundant with one another. In New York, this needs no argument, judging by conversations with many New Yorkers, even ones who aren’t railfans, who recognize the extent of redundancy in the system. It would be useful to design weekend service changes to take advantage of this redundancy and not shut down multiple lines that could substitute for each other. In the case of last weekend, if a full shutdown of the 2 and 3 between 96th Street and the Bronx was unavoidable, then the other north-south lines through Upper Manhattan should not be shut down.

Thus, the first principle I’d like to propose for weekend shutdowns is, if one line is shut for repairs, then parallel lines should be fully open. This should cover shutdowns as well as one-way running, in which one direction is only served by express trains and passengers wishing to access local stations are told to ride an express trains and change to a local train going in the opposite direction.

In fact, given the extent of redundancy in the core, I would propose that if local service is shut down in one direction, then it should be shut down in the other direction as well. Backtracking is cumbersome and rarely worth it: stop spacing is often close enough that walking from the express stop is faster, and in Manhattan it’s usually easier to just go on a parallel line instead.

Then, to compensate for loss of service on a line that’s being closed for repairs, there should be more service on parallel lines. Subway service changes in New York, called general orders, or GOs, fall under a labor agreement in which train operators and conductors are still paid for the time they would’ve had to work if service had run normally. The MTA should negotiate a change in which those drivers and conductors can be redistributed to nearby subway lines without this counting as overtime. If express trains on a route are closed, then there should be more local service, and if a trunk line is closed, as the 2 and 3 were last weekend, then there should be more service on parallel lines (in this case, the 1, 4, 5, A, and D) to absorb the extra ridership. With reduced service, the trains can get quite busy, more so than the crowding guidelines indicate, if my weekend trips are any indication.

Finally, the MTA should build crossovers and switches to enable more efficient single-tracking. This is unlikely to work on four-track lines, since trains would have to cross three tracks to get around a work zone, but on two-track lines, including the L, the 7, and most tails outside the Manhattan core, it would be useful, especially on lines that use island platforms rather than side platforms. On the newest lines, which use bored tunnel, it’s easy to do maintenance on one track without disturbing the other track, as long as there are crossovers at regular locations. On the older lines the situation is the opposite: trains need to slow near work zones, unless some hard barriers are built between parallel tracks, but installing new crossovers is relatively easy. More shutdowns may be required to install such switches, but the subsequent benefits to making weekend trackwork easier are substantial.