NYTIP INSIDER – on the delicate balance between de-interlining and destabilization

If you’ve read my blog for any length of time, you’ve noticed I’m hard at work on a personal project called the New York Transportation Improvement Plan, or NYTIP. With regard to subways, NYTIP prescribes a three-point plan – enhance, extend, and expand. NYTIP is about the long game, but in order to win that game, one must lay the proper foundation.

The centerpiece of the first point – enhance – is something called “de-interlining”. As designed, the NYC Subway promotes as many one-seat rides to Manhattan’s Central Business District (CBD – generally the area on or below 63rd Street) as possible. A consequence of this is something called “reverse branching“, where lines outside the CBD split and/or merge into different trunk lines inside the CBD. These merges induce delays and limit capacity on these lines.

“De-interlining”, therefore, redistributes lines to eliminate merges, improving total capacity. However, this results in fewer one-seat rides, increasing the likelihood that one must transfer to reach their final destination. Thus, de-interlining plans should either enhance or simplify transfers where possible.

As I drafted NYTIP, I came up with an initial series of proposals, then started a series of updates with even more radical proposals (such as the West 4th Street swap). However, this may be a bridge too far. There is a point where de-interlining – even if it induces service increases on several lines or branches – could create more problems than it solves. This is especially true in the case of NYTIP, where de-interlining isn’t merely a plan to fix and improve the NYC Subway, but Step 1 of such a plan; hence, any de-interlining plan should balance the needs of the subway’s existing ridership and be compatible with the long-term strategy for the subway. Since de-interlining necessarily “redraws the map”, it should be done in a way that does not require a second “redrawing” after subway extension and expansion.

Basically, what I’m saying is that “more radical” may not be the best way to go when it comes to NYTIP (though note that things like “de-interlining” and subway expansion may already be seen as radical!). Hence, it’s back to the lab again for more refinement.

I don’t expect my plans to be perfect. But I do have an end in mind when it comes to the NYC Subway, and with so many ideas floating in my head, it’s easy to get lost in ’em! I do appreciate all who read and comment on NYTIP! Rest assured that there’s a lot more to come! Until next time!

discuss respectfully!