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NYC has one of the best open data portals out there. Kudos to all the teams and agencies who manage it.



Shoutout to Philippe Vibien for creating “NYC Subway Stringlines”, one of my favorite (and certainly most used) data visualizations ever. Made possible by the MTA’s GTFS RT feed.

https://pvibien.com/stringline.htm

Note: If you’re checking this out around 6 PM EST, look at the E train to get an idea of what a bad night on the subway looks like.

Each line on the graph represents a train with the Y axis as stations and the X axis representing time. You can follow the trip of the train and get an idea for how well the line is running based on the straightness of the line. If you see areas where the line is flat in the Y axis, you know that a train is being held at a station.

Here’s an example where “stringlines” provide information that a countdown clock couldn’t convey: https://i.imgur.com/u5VGqH4.jpeg

Because the “line” is not progressing past 5th Ave/53rd st, we know that that is where the issue is occurring. A countdown timer would simply either say static or start adding time, but you wouldn’t know how far the next train is from you.

Here’s another example: https://i.imgur.com/mrvrbUt.jpeg

What I can glean from this is that the E train is running with much lower frequency than it was an hour ago, so I should expect longer wait times.

It’s truly a marvelous invention.


I also love this visualization and remember being blown away when I first saw it!

Two notes: 1. These “stringlines” are also known as Time-Space Diagrams in the transit industry, and they’ve been around for a while. e.g. https://www.researchgate.net/figure/Time-space-diagrams-of-t...

In fact Vibien cites as inspiration the official NYCT stringline paper: https://www.worldtransitresearch.info/research/5936/

2. I’ve noticed that at least on the A, the viz is inaccurate? It’s missing a lot of trains.


Found a nice video digging into traffic time-space diagrams: https://youtu.be/E_tk6BGhYDE

There's a nice a-ha moment when he shows aerial photographs.


I knew he cited a NYCT paper on the page itself, but I've never seen the paper so I didn't know how similar they were. Regardless, making this available to the public is laudable in-of-itself. Thanks for the sources, will check out later!




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