4 ms·

The MTA moves 5.5 million people daily, why don't you do the math on door-to-door individual vehicles for all of them? Like, major office buildings can have 10

The MTA moves 5.5 million people daily, why don't you do the math on door-to-door individual vehicles for all of them? Like, major office buildings can have 10,000 workers in them, and there may be a bunch of such buildings in a complex. Do the math, figure out what sort of station you need to build to let those people arrive at work in the morning in their individual pods. And the safety devices you describe are what keeps stories like "subways crash, 500 killed" from being commonplace. What exactly happens when a couple of Boring Company vehicles crash in a tube at 200kph? How do you extract them? What happens to them, and what happens to the other 75 vehicles approaching in the tubes behind them at 200kph? Has any thought at all been given to this?

paulsutter 8y ago
The Boring Company is planning multipassenger pods, you'll learn more next week. Capacity planning would be more similar to elevators than subway stations. Stations would be in the building basement levels. Those hardwired safety mechanisms certainly work, but are primarily needed to overcome human error. We're all willing to fly on planes with autopilot, and self-driving vehicles in tunnels will be safer. Elon is talking about building 30 or more levels in dense cities. A guy who lands rocket boosters for reuse has certainly thought through the details of an underground transportation system.
- jakecopp 8y ago
  You can't just appeal to Elon Musk assuming he knows all and has figured this out. Have you ever travelled beyond the US and seen an international subway system? I haven't travelled much but there are some amazing systems out there. Japan had 130mph bullet trains in 1964, can you believe that? They're maxing out at 375mph with levitating trains now, and they actually exist unlike Elon's ideas. Why do you give ideas more credit then something that already exist and work brilliantly? Last year Japan Rail issued an apology because one of their trains left a station 20 seconds early [1]. Even in my town of Sydney, with huge suburban sprawl, we have beautiful, quiet, air conditioned, double decker trains that go to most suburbs and cost $1.50 to $4. The future has already arrived, the US just doesn't have it yet. https://mobile.abc.net.au/news/2017-11-17/japan-train-apology-for-leaving-20-seconds-early/9161456 https://mobile.abc.net.au/news/2017-11-17/japan-train-apolog...
  - paulsutter 8y ago
    Yes I lived in Japan for a few years and love the transportation system there. The shinkansen is wonderful, but the hyperloop will be substantially faster in door to door time, because hyperloop cars will also transit the local loop system. Most transportation systems are not designed to optimize door to door time. Even by express train, it's a long trip from Narita airport to Tokyo.
    - shanghaiaway 8y ago
      The hyperloop won't do anything because it will never exist. The distance between Tokyo and Narita Airport is the same regardless of mode of transportation.
      - paulsutter 8y ago
        Yes the distance is the same, which is why time spent waiting and travel speed matter so much. I'm personally more interested in the impact on local transportation (loop) than intercity (hyperloop)
  - dashundchen 8y ago
    New Yorkers don't have to cross an ocean to see good transit. Even closer to New York at just a day's train ride, the third busiest North American transit system is Montreal. https://en.wikipedia.org/wiki/Montreal_Metro https://en.wikipedia.org/wiki/Montreal_Metro I was recently there to visit - the metro is beautifully efficient, on-time, clean, and frequent. Trains every 4 minutes during work hours like clockwork. Connected to an extensive underground pedestrian network downtown, and frequent bus service outside of the core (even on Sundays). And an unlimited weekend pass valid on both the bus and metro was only ~13 USD.
- otabdeveloper2 8y ago
  > A guy who lands rocket boosters for reuse has certainly thought through the details of an underground transportation system. Landing rocket boosters is about a thousand times easier than underground transportation. Reusable booster tech has existed since the 1960's. It wasn't developed further for two reasons: a) It's massively wasteful because you have to carry the fuel for the return trip. b) The boosters need to be refurbished afterwards anyways, which is actually more expensive than building a new rocket. (More ways to screw up and less leeway for economies of scale and standardization.) As far as I know, Musk hasn't solved these problems and isn't even planning to.
adrianmonk 8y ago
Obviously the scale is huge, but conventional trains have inefficiencies. Suppose the average rider's trip is 10 stops. At every stop where the rider does not get off, there is inefficiency because they sitting there, taking up a seat on a train that is stopped. You're not only wasting their time, you're also wasting train capacity. The naive solution is to make the train longer. Which works, but it's costly because you also have to make the platform longer. In a subway system, that's expensive. And the worst part is, you have to do it for every station the train will stop at, even the ones that aren't as busy. This is, of course, why express trains exist. Eliminate some stops and you reduce all these problems. But the more stops you eliminate, the fewer people can use the express (because it doesn't stop where they're going), so there's an unavoidable compromise. In the days before automation, this was probably the best that could be done. But now that automation exists, new approaches are possible. Since you no longer need a driver per train, you now have the option of making trains smaller. And it's also possible to group people together by starting point and destination. So in theory you could make every train an "express train", one with zero stops other than starting point and destination. No seats wasted on making people wait in a non-moving train while others get on/off. So you can eliminate an inefficiency that you never could before. Of course, every train needs headway for safety reasons. More smaller trains instead of fewer larger trains means that's harder. So it's not without its own, different limitations. Maybe automation has fast enough reaction time (or other tricks) that can cut down on the physical space needed for headway. Anyway, the point is that much smaller vehicles might actually increase efficiency, and this is what the Boring Company seems to be planning to do.
- jcranmer 8y ago
  You're completely wrong. On a fixed guideway system--that includes vanilla railways and things like monorails--a train that is stopped completely blocks the entire track, and cannot be routed around except via switches. The minimum headway between trains is dominated by switch fouling: how long it will take a train to pass over the switch, and then for the switch to switch to a different track, before the signal can go green again. You'll also want some extra padding on top of that for timetabled trains, to take into account unexpected long station dwells and schedule recovery. The throughput of most subways is about 26 trains per hour. With good signalling and track management, you can push it to about 36 trains per hour on a branched line; an unbranched line (which simplifies management a lot!) can get up to 45 trains per hour, but those are definitely not typical numbers. Train length doesn't impact these numbers much, definitely not at the scale of variation being discussed. Express trains require dedicated tracks to be able to bypass parked trains, or insanely good timetable-keeping to not get stuck behind a local train before a bypass. NYC built a lot of its trunks to 4 tracks, which allows it to make local/express trains, but most systems have found it's easier to just build another 2-track trunk a few blocks away than to try to add 4-tracks to the 2-track trunk. The idea of trying to use tiny cars with much narrower safety margins for headways is the idea behind personal rapid transit, but PRT systems have been shown to have utterly lousy throughputs: pulling 10,000 people/hour on a trunk PRT line would be a significant milestone, whereas the standard 8-car train on a 26TPH subway easily pulls 25,000 people/hour without needing much effort.

paulsutter 8y ago

The Boring Company is planning multipassenger pods, you'll learn more next week. Capacity planning would be more similar to elevators than subway stations. Stations would be in the building basement levels. Those hardwired safety mechanisms certainly work, but are primarily needed to overcome human error. We're all willing to fly on planes with autopilot, and self-driving vehicles in tunnels will be safer. Elon is talking about building 30 or more levels in dense cities. A guy who lands rocket boosters for reuse has certainly thought through the details of an underground transportation system.

jakecopp 8y ago
You can't just appeal to Elon Musk assuming he knows all and has figured this out. Have you ever travelled beyond the US and seen an international subway system? I haven't travelled much but there are some amazing systems out there. Japan had 130mph bullet trains in 1964, can you believe that? They're maxing out at 375mph with levitating trains now, and they actually exist unlike Elon's ideas. Why do you give ideas more credit then something that already exist and work brilliantly? Last year Japan Rail issued an apology because one of their trains left a station 20 seconds early [1]. Even in my town of Sydney, with huge suburban sprawl, we have beautiful, quiet, air conditioned, double decker trains that go to most suburbs and cost $1.50 to $4. The future has already arrived, the US just doesn't have it yet. https://mobile.abc.net.au/news/2017-11-17/japan-train-apology-for-leaving-20-seconds-early/9161456 https://mobile.abc.net.au/news/2017-11-17/japan-train-apolog...
- paulsutter 8y ago
  Yes I lived in Japan for a few years and love the transportation system there. The shinkansen is wonderful, but the hyperloop will be substantially faster in door to door time, because hyperloop cars will also transit the local loop system. Most transportation systems are not designed to optimize door to door time. Even by express train, it's a long trip from Narita airport to Tokyo.
  - shanghaiaway 8y ago
    The hyperloop won't do anything because it will never exist. The distance between Tokyo and Narita Airport is the same regardless of mode of transportation.
    - paulsutter 8y ago
      Yes the distance is the same, which is why time spent waiting and travel speed matter so much. I'm personally more interested in the impact on local transportation (loop) than intercity (hyperloop)
- dashundchen 8y ago
  New Yorkers don't have to cross an ocean to see good transit. Even closer to New York at just a day's train ride, the third busiest North American transit system is Montreal. https://en.wikipedia.org/wiki/Montreal_Metro https://en.wikipedia.org/wiki/Montreal_Metro I was recently there to visit - the metro is beautifully efficient, on-time, clean, and frequent. Trains every 4 minutes during work hours like clockwork. Connected to an extensive underground pedestrian network downtown, and frequent bus service outside of the core (even on Sundays). And an unlimited weekend pass valid on both the bus and metro was only ~13 USD.
otabdeveloper2 8y ago
> A guy who lands rocket boosters for reuse has certainly thought through the details of an underground transportation system. Landing rocket boosters is about a thousand times easier than underground transportation. Reusable booster tech has existed since the 1960's. It wasn't developed further for two reasons: a) It's massively wasteful because you have to carry the fuel for the return trip. b) The boosters need to be refurbished afterwards anyways, which is actually more expensive than building a new rocket. (More ways to screw up and less leeway for economies of scale and standardization.) As far as I know, Musk hasn't solved these problems and isn't even planning to.

adrianmonk 8y ago

Obviously the scale is huge, but conventional trains have inefficiencies. Suppose the average rider's trip is 10 stops. At every stop where the rider does not get off, there is inefficiency because they sitting there, taking up a seat on a train that is stopped. You're not only wasting their time, you're also wasting train capacity. The naive solution is to make the train longer. Which works, but it's costly because you also have to make the platform longer. In a subway system, that's expensive. And the worst part is, you have to do it for every station the train will stop at, even the ones that aren't as busy. This is, of course, why express trains exist. Eliminate some stops and you reduce all these problems. But the more stops you eliminate, the fewer people can use the express (because it doesn't stop where they're going), so there's an unavoidable compromise. In the days before automation, this was probably the best that could be done. But now that automation exists, new approaches are possible. Since you no longer need a driver per train, you now have the option of making trains smaller. And it's also possible to group people together by starting point and destination. So in theory you could make every train an "express train", one with zero stops other than starting point and destination. No seats wasted on making people wait in a non-moving train while others get on/off. So you can eliminate an inefficiency that you never could before. Of course, every train needs headway for safety reasons. More smaller trains instead of fewer larger trains means that's harder. So it's not without its own, different limitations. Maybe automation has fast enough reaction time (or other tricks) that can cut down on the physical space needed for headway. Anyway, the point is that much smaller vehicles might actually increase efficiency, and this is what the Boring Company seems to be planning to do.

jcranmer 8y ago
You're completely wrong. On a fixed guideway system--that includes vanilla railways and things like monorails--a train that is stopped completely blocks the entire track, and cannot be routed around except via switches. The minimum headway between trains is dominated by switch fouling: how long it will take a train to pass over the switch, and then for the switch to switch to a different track, before the signal can go green again. You'll also want some extra padding on top of that for timetabled trains, to take into account unexpected long station dwells and schedule recovery. The throughput of most subways is about 26 trains per hour. With good signalling and track management, you can push it to about 36 trains per hour on a branched line; an unbranched line (which simplifies management a lot!) can get up to 45 trains per hour, but those are definitely not typical numbers. Train length doesn't impact these numbers much, definitely not at the scale of variation being discussed. Express trains require dedicated tracks to be able to bypass parked trains, or insanely good timetable-keeping to not get stuck behind a local train before a bypass. NYC built a lot of its trunks to 4 tracks, which allows it to make local/express trains, but most systems have found it's easier to just build another 2-track trunk a few blocks away than to try to add 4-tracks to the 2-track trunk. The idea of trying to use tiny cars with much narrower safety margins for headways is the idea behind personal rapid transit, but PRT systems have been shown to have utterly lousy throughputs: pulling 10,000 people/hour on a trunk PRT line would be a significant milestone, whereas the standard 8-car train on a 26TPH subway easily pulls 25,000 people/hour without needing much effort.