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Using Countdown Clock Data to Understand the New York City Subway

toddwschneider.com

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Re: Using Countdown Clock Data to Understand the New York City Subway

#11

Post by onion2k »

RossM wrote: post #6
anthonybsd wrote: post #2

>The L train is also the only line that uses modern >communications-based train control (CBTC), which allows >trains to operate in a more automated fashion. It's not "more automated fashion", it's fully automated, LIDAR and all - they are fully autonomous. L trains have operators because of unions throwing a fit and most of the times they sit there twiddling their thumbs.

I feel it's worth reminding that there's a difference between autonomous trains, driverless trains and unattended trains. The L train is considered Grade of Automation 2 - it starts and stops itself, though it has someone in the driver's seat who controls the doors and gives control to the ATO system. Driverless (GoA3) trains move that role to a train attendant who controls the doors from within the train. Unattended…

Does the DLR count as a GoA3 train? There isn't a driver sitting at the front.

Re: Using Countdown Clock Data to Understand the New York City Subway

#12

Post by prophesi »

exegete wrote: post #10

The author does briefly mention this, but the countdown clocks are not every accurate. I often see a wait time of "3 min" and then it's there in the next 10 seconds. Or you can see the opposite where it just hangs on "3 min" for a minute or two and was really 5 minutes away. In reality it should just report at its accuracy, e.g., " PS, why do people stick their necks over the tracks to look if a train is coming?

Yeah, I've heard of one vendor needing to use both the real-time and static-time data in such a way to determine how off-schedule the trains are, and using that information to discard the unreliable real-time data bits.

Re: Using Countdown Clock Data to Understand the New York City Subway

#13

Post by macintux »

turdnagel wrote: post #5

Bless Todd W. Schneider and his in depth mathematical analyses of travel times in NYC. See also his epic Uber/Taxi post: http://toddwschneider.com/posts/analyzing-1-1-billion-nyc-ta...

I found it interesting to contemplate how much harder it would be for someone to do this level of analysis and draw conclusions from it if they weren't physically proximate.

I love remote work, and I hope to sustain it for the rest of my career, but there is something to be said for direct exposure to the systems you study.

(It also makes me appreciate all the more how hard it must be for archaeologists et al to glean details of the past from fragmentary evidence of a world long gone.)

Re: Using Countdown Clock Data to Understand the New York City Subway

#14

Post by blattimwind »

eumoria wrote: post #3
anthonybsd wrote: post #2

>The L train is also the only line that uses modern >communications-based train control (CBTC), which allows >trains to operate in a more automated fashion. It's not "more automated fashion", it's fully automated, LIDAR and all - they are fully autonomous. L trains have operators because of unions throwing a fit and most of the times they sit there twiddling their thumbs.

I don't mind paying a man to sit at the head of the train even if they're autonomous. I also don't believe making all the lines CBTC are going to solve the core issues of breakdowns outside of an ancient signaling system. Some of the lines in NYC are still using R32 cars[1]. They were built in 1965 that is ludicrous. Granted, they were refurbished in the late 80s but that's still 30 years ago. That said most of the l…

These all look like they're made in the 70s, including the supposedly modern R160.

Re: Using Countdown Clock Data to Understand the New York City Subway

#15

Post by Piskvorrr »

fredley wrote: post #4
anthonybsd wrote: post #2

>The L train is also the only line that uses modern >communications-based train control (CBTC), which allows >trains to operate in a more automated fashion. It's not "more automated fashion", it's fully automated, LIDAR and all - they are fully autonomous. L trains have operators because of unions throwing a fit and most of the times they sit there twiddling their thumbs.

We have this system on a few lines in London now. The only job now for the train 'drivers' is to open and close the doors and the platform. https://en.wikipedia.org/wiki/Automation_of_the_London_Under...

...if the train is on happy path. And believe me, there are some really ugly unhappy paths where underground passenger rail is concerned; we definitely have no technology autonomous enough for that.

https://en.wikipedia.org/wiki/List_of_London_Underground_acc...

Re: Using Countdown Clock Data to Understand the New York City Subway

#16

Post by erikig »

Kudos to MTA NYC - the raw data to perform analysis is available here: http://web.mta.info/developers/MTA-Subway-Time-historical-da...

The details on how the countdown clocks work is available here: https://www.amny.com/transit/subway-countdown-clock-complain...

GTFS Format: https://developers.google.com/transit/gtfs-realtime/

Re: Using Countdown Clock Data to Understand the New York City Subway

#17

Post by tzahola »

RossM wrote: post #6
anthonybsd wrote: post #2

>The L train is also the only line that uses modern >communications-based train control (CBTC), which allows >trains to operate in a more automated fashion. It's not "more automated fashion", it's fully automated, LIDAR and all - they are fully autonomous. L trains have operators because of unions throwing a fit and most of the times they sit there twiddling their thumbs.

I feel it's worth reminding that there's a difference between autonomous trains, driverless trains and unattended trains. The L train is considered Grade of Automation 2 - it starts and stops itself, though it has someone in the driver's seat who controls the doors and gives control to the ATO system. Driverless (GoA3) trains move that role to a train attendant who controls the doors from within the train. Unattended…

>but they're still required to pay attention

Like that Uber test driver?

Re: Using Countdown Clock Data to Understand the New York City Subway

#18

Post by Symbiote »

onion2k wrote: post #11
RossM wrote: post #6

Earlier quoted context omitted.

I feel it's worth reminding that there's a difference between autonomous trains, driverless trains and unattended trains. The L train is considered Grade of Automation 2 - it starts and stops itself, though it has someone in the driver's seat who controls the doors and gives control to the ATO system. Driverless (GoA3) trains move that role to a train attendant who controls the doors from within the train. Unattended…

Does the DLR count as a GoA3 train? There isn't a driver sitting at the front.

That's correct.

Re: Using Countdown Clock Data to Understand the New York City Subway

#19

Post by Symbiote »

Piskvorrr wrote: post #15
fredley wrote: post #4

Earlier quoted context omitted.

We have this system on a few lines in London now. The only job now for the train 'drivers' is to open and close the doors and the platform. https://en.wikipedia.org/wiki/Automation_of_the_London_Under...

...if the train is on happy path. And believe me, there are some really ugly unhappy paths where underground passenger rail is concerned; we definitely have no technology autonomous enough for that. https://en.wikipedia.org/wiki/List_of_London_Underground_acc...

A system so safe, that almost all of the accidents in the last 50 years say "no serious injuries" or even "no injuries".

One driver was killed in 1968, another in 1984, someone broken a leg in 2003, and a passenger in 2004 dragged along a platform.

(The accident in 1975 was with a mainline rail train, not a metro train, I'm not sure why it's on the list.)

Re: Using Countdown Clock Data to Understand the New York City Subway

#20

Post by Symbiote »

fredley wrote: post #9
RossM wrote: post #6

Earlier quoted context omitted.

I feel it's worth reminding that there's a difference between autonomous trains, driverless trains and unattended trains. The L train is considered Grade of Automation 2 - it starts and stops itself, though it has someone in the driver's seat who controls the doors and gives control to the ATO system. Driverless (GoA3) trains move that role to a train attendant who controls the doors from within the train. Unattended…

The DLR is GoA 4. It wasn't exactly smooth sailing at first: https://www.youtube.com/watch?v=mwruoagYq0U

The DLR is level 3.

The video is from 1988 (good find!), but the only accidents ever to have occurred were under manual override.

The Copenhagen Metro is an example of a level 4 underground system. It's fairly new, so the tunnels all have an adjacent walkway which can be used in an emergency.

https://en.wikipedia.org/wiki/Docklands_Light_Railway#Accide...

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