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If you think “make the countdown clocks work” is a small thing you haven’t researched this problem thoroughly. https://www.theatlantic.com/technology/archive/2

by ixtli 7y ago

If you think “make the countdown clocks work” is a small thing you haven’t researched this problem thoroughly. https://www.theatlantic.com/technology/archive/2015/11/why-dont-we-know-where-all-the-trains-are/415152/ https://www.theatlantic.com/technology/archive/2015/11/why-d...

notyourday 7y ago
Yes, it is a very small thing. Start with automated lines ( the L ) where you know the location of every train. You know the speed of every train at every point. Now it is a standard algebra problem that 15 year olds were solving 20 years ago in algebra/comp sci exams, using pen and paper - it was pre-calc so they invented how they could divide the track into equal section and compute the time it takes the train it should take the train to get to the station by approximating the unknown time based off the time that it took the train to pass the sections behind it. On non-automated lines start by adding god damn train trackers to the individual trains and start splitting the blind sections of the track by adding cameras and sensors. They don't need to make the lines automatic. They just need to add visibility. None of this is difficult. MTA and "infrastructure is hard" people are full of excuses. They are the same people who were saying that the L should be fully shutdown for 18 months when now we have MTA announcement that even with the partial shutdown they are way ahead of schedule with the tunnel work so they can start doing the station work. There should never be the case when it says a train is 8 minutes away and a train behind it is 9 minutes away when a train gets to the station in 2 minutes and the train behind it gets to the station in 5 minutes.
- tialaramex 7y ago
  What you've done there is you've found a very complicated way to solve entirely the wrong problem. Bravo, I guess.
  - notyourday 7y ago
    "I hate the way our application is written. We need to be able to instrument it and also rewrite all that icky old logic. Basically we should rewrite the entire thing. It will take us about 3 years"
- nerdponx 7y ago
  On non-automated lines start by adding god damn train trackers to the individual trains and start splitting the blind sections of the track by adding cameras and sensors. They don't need to make the lines automatic. They just need to add visibility. This is not a small thing
  - notyourday 7y ago
    Yes, because MTA does not have a right of way or power in the tunnels. Oh wait, it does! It must be because Wifi/BT enabled trip sensors sensors don't exist. Oh wait, they do. So it must be because we have never done Bluetooth/wifi tracking of clients based on addresses. Oh wait, we did.
    - jrockway 7y ago
      They are already using Bluetooth transponders on B-division trains. The arrival time is then inferred from the arrival of that transponder at the previous station. https://www.amny.com/transit/mta-to-install-subway-countdown-clocks-on-all-lettered-lines-1.12619143 https://www.amny.com/transit/mta-to-install-subway-countdown... I think they rolled this out from prototype to full implementation in less than a year, which is very impressive.
- evanelias 7y ago
  > There should never be the case when it says a train is 8 minutes away and a train behind it is 9 minutes away when a train gets to the station in 2 minutes and the train behind it gets to the station in 5 minutes. This is like complaining about a car trip taking less time than Google Maps predicted, due to an accident ahead of you getting cleared up before you reach that stretch of road. Unpredictable things happen on public transit: sick passengers, police activity, signal problems, mechanical failures, cascading delays causing platform crowding and longer board times. These things cause delays, and then on the tail-end of the event, sometimes they cause trains to be "early" when the delay clears up. Even then, though, in my experience it's pretty rare that the train comes before the time on the countdown clock. All things considered, I find the countdown clocks to be pretty accurate a vast majority of the time. And they're certainly a huge improvement over how things were before they were installed: a loud beeping noise about a minute before the train arrived, sometimes paired with a muffled inaudible announcement from the station attendant over an ancient PA system.
  - notyourday 7y ago
    So about 30 minutes after I posted it I'm on the L and there's a train to Lorimer at in 8 minutes, train to Manhattan in 19 minutes. That's on the countdown clock. This will put the Manhattan train above the Broadway Junction. There's an announcement on the loud speaker that there's no service between Broadway Junction and Canarsie in both directions because of police activity. Two minutes later, according to the count down clock there's a train to Lorimer in 6 minutes and to Manhattan in 17 minutes. Followed by 5 - 16 and 3 - 13. There's still an announcement that there's no service between Broadway Junction and Canarsie in both directions. But there are magical countdown clock connected trains that will be now here in 3 minutes and 10 minutes. Oh wait, the magical clock is saying there's a train entering a platform! It is going to Lorimer and it is followed by a train to Manhattan! The clock is at zero and it is blinking! All aboard the subway track! This went on for about 40 minutes. Twitter says there's no service. Countdown clock says there's a train coming! Google transit says there's no train. Countdown clock says there's one! And when the service was restored the countdown clock said the next train was going to Lorimer and it was finally 6 minutes away. Except that a train to Manhattan was pulling into the station. The countdown clocks are garbage because the only time that they matter is when there are sick passengers, police activity, mechanical failures and cascading delays -- otherwise we know the train will be here in about ~4-5 minutes and that's exactly the time when the countdown clocks cannot provide reliable information. MTA should finish that project and make it work. After that they can pick their next "digital initiative"

by ixtli 7y ago

notyourday 7y ago

Yes, it is a very small thing. Start with automated lines ( the L ) where you know the location of every train. You know the speed of every train at every point. Now it is a standard algebra problem that 15 year olds were solving 20 years ago in algebra/comp sci exams, using pen and paper - it was pre-calc so they invented how they could divide the track into equal section and compute the time it takes the train it should take the train to get to the station by approximating the unknown time based off the time that it took the train to pass the sections behind it. On non-automated lines start by adding god damn train trackers to the individual trains and start splitting the blind sections of the track by adding cameras and sensors. They don't need to make the lines automatic. They just need to add visibility. None of this is difficult. MTA and "infrastructure is hard" people are full of excuses. They are the same people who were saying that the L should be fully shutdown for 18 months when now we have MTA announcement that even with the partial shutdown they are way ahead of schedule with the tunnel work so they can start doing the station work. There should never be the case when it says a train is 8 minutes away and a train behind it is 9 minutes away when a train gets to the station in 2 minutes and the train behind it gets to the station in 5 minutes.

tialaramex 7y ago
What you've done there is you've found a very complicated way to solve entirely the wrong problem. Bravo, I guess.
- notyourday 7y ago
  "I hate the way our application is written. We need to be able to instrument it and also rewrite all that icky old logic. Basically we should rewrite the entire thing. It will take us about 3 years"
nerdponx 7y ago
On non-automated lines start by adding god damn train trackers to the individual trains and start splitting the blind sections of the track by adding cameras and sensors. They don't need to make the lines automatic. They just need to add visibility. This is not a small thing
- notyourday 7y ago
  Yes, because MTA does not have a right of way or power in the tunnels. Oh wait, it does! It must be because Wifi/BT enabled trip sensors sensors don't exist. Oh wait, they do. So it must be because we have never done Bluetooth/wifi tracking of clients based on addresses. Oh wait, we did.
  - jrockway 7y ago
    They are already using Bluetooth transponders on B-division trains. The arrival time is then inferred from the arrival of that transponder at the previous station. https://www.amny.com/transit/mta-to-install-subway-countdown-clocks-on-all-lettered-lines-1.12619143 https://www.amny.com/transit/mta-to-install-subway-countdown... I think they rolled this out from prototype to full implementation in less than a year, which is very impressive.
evanelias 7y ago
> There should never be the case when it says a train is 8 minutes away and a train behind it is 9 minutes away when a train gets to the station in 2 minutes and the train behind it gets to the station in 5 minutes. This is like complaining about a car trip taking less time than Google Maps predicted, due to an accident ahead of you getting cleared up before you reach that stretch of road. Unpredictable things happen on public transit: sick passengers, police activity, signal problems, mechanical failures, cascading delays causing platform crowding and longer board times. These things cause delays, and then on the tail-end of the event, sometimes they cause trains to be "early" when the delay clears up. Even then, though, in my experience it's pretty rare that the train comes before the time on the countdown clock. All things considered, I find the countdown clocks to be pretty accurate a vast majority of the time. And they're certainly a huge improvement over how things were before they were installed: a loud beeping noise about a minute before the train arrived, sometimes paired with a muffled inaudible announcement from the station attendant over an ancient PA system.
- notyourday 7y ago
  So about 30 minutes after I posted it I'm on the L and there's a train to Lorimer at in 8 minutes, train to Manhattan in 19 minutes. That's on the countdown clock. This will put the Manhattan train above the Broadway Junction. There's an announcement on the loud speaker that there's no service between Broadway Junction and Canarsie in both directions because of police activity. Two minutes later, according to the count down clock there's a train to Lorimer in 6 minutes and to Manhattan in 17 minutes. Followed by 5 - 16 and 3 - 13. There's still an announcement that there's no service between Broadway Junction and Canarsie in both directions. But there are magical countdown clock connected trains that will be now here in 3 minutes and 10 minutes. Oh wait, the magical clock is saying there's a train entering a platform! It is going to Lorimer and it is followed by a train to Manhattan! The clock is at zero and it is blinking! All aboard the subway track! This went on for about 40 minutes. Twitter says there's no service. Countdown clock says there's a train coming! Google transit says there's no train. Countdown clock says there's one! And when the service was restored the countdown clock said the next train was going to Lorimer and it was finally 6 minutes away. Except that a train to Manhattan was pulling into the station. The countdown clocks are garbage because the only time that they matter is when there are sick passengers, police activity, mechanical failures and cascading delays -- otherwise we know the train will be here in about ~4-5 minutes and that's exactly the time when the countdown clocks cannot provide reliable information. MTA should finish that project and make it work. After that they can pick their next "digital initiative"