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New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

nytimes.com

1–10 of 162 posts

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#2
So the transit authority decided that it was more important to have trains evenly spaced out (to minimize the worst case wait times), but the tradeoff was less total capacity and thus more crowded trains.

I'm really not sure which is the better case. Trains always arrive in a short time, but can be full. Or you may have to wait longer for a train, and then a little longer still for the train right behind that train that isn't as full.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#3
It would seem one could analyze the performance in this day of big data and find a more efficient plan for scheduling the trains and adjusting in real time. Maybe the system is too unpredictable to make this possible. Even so it would be fun to try to model the entire system and try.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#4
I used to take the 456 line on Lexington Ave. back and forth between Home & Work for the past 5 years. In January, the Q line on 86th st. opened, and although it takes me ~10 minutes longer each way, it is a MUCH more pleasant experience.

The 456 is a nightmare, and I can tell you first hand, that it is crowded to a point where it is inhumane (imagine people literally fighting for a spot to have the "privilege" to smell the arm-pits in their faces).

The Q line is well worth the headache, and the frustration of dealing with the 456.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#5

I used to take the 456 line on Lexington Ave. back and forth between Home & Work for the past 5 years. In January, the Q line on 86th st. opened, and although it takes me ~10 minutes longer each way, it is a MUCH more pleasant experience. The 456 is a nightmare, and I can tell you first hand, that it is crowded to a point where it is inhumane (imagine people literally fighting for a spot to have the "privilege" to sm…

I ride the 6 every week day -- luckily I don't go during prime rush hour, but even when I do, I don't understand why more people don't go to the end car. It's ALWAYS less full any time of day.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#6
post #2

So the transit authority decided that it was more important to have trains evenly spaced out (to minimize the worst case wait times), but the tradeoff was less total capacity and thus more crowded trains. I'm really not sure which is the better case. Trains always arrive in a short time, but can be full. Or you may have to wait longer for a train, and then a little longer still for the train right behind that train t…

That’s a good summary.

This kind of problem is not easy to solve- it’s not the kind of thing that has a closed form solution. You typically use a discrete event simulator to model the outcome of different strategies. It seems clear to me, though, that the answer is going to be a mix of “maximize number of trains” and “space them out nicely” during rush hour. I bet the optimal strategy trades off those two variables based on some probability distribution of “expected number of available trains” over time, such that if the number of likely available trains is lower you space them out more, and so on.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#8

I used to take the 456 line on Lexington Ave. back and forth between Home & Work for the past 5 years. In January, the Q line on 86th st. opened, and although it takes me ~10 minutes longer each way, it is a MUCH more pleasant experience. The 456 is a nightmare, and I can tell you first hand, that it is crowded to a point where it is inhumane (imagine people literally fighting for a spot to have the "privilege" to sm…

Somewhat similar story, except I am now biking pretty much full time. The trains aren't sufficiently reliable anymore.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#9
post #2

So the transit authority decided that it was more important to have trains evenly spaced out (to minimize the worst case wait times), but the tradeoff was less total capacity and thus more crowded trains. I'm really not sure which is the better case. Trains always arrive in a short time, but can be full. Or you may have to wait longer for a train, and then a little longer still for the train right behind that train t…

its more than just that though. it's a legit safety issue. the switches are old and have been breaking down at spectacular rates. if a switch breaks when trains on the line are too close too each other there is a much higher chance for a collision due to one of the trains breaking too soon or too late. spacing them out more evenly reduces the chance of that scenario.

Re: New York’s Subways Are Not Just Delayed, Some Trains Don’t Run at All

#10
post #7

Why would it take 50 years to install signalling across the system ? This doesn't sound right at all.

the only right way to answer that question involves a 10000 word history of the politics of the MTA, the finances of NY state and NY city, bankruptcies, budget shortfalls, political corruption and misdirection, very messy labor union politics, and the complexities of running a giant subway system 24/7 in a region that suffers significant damage every year from hurricanes and ice storms.
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