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> with small pods you will never get the throughput with any kind of safety margin between them. You assert this like it's a fact. But it seems like something

> with small pods you will never get the throughput with any kind of safety margin between them. You assert this like it's a fact. But it seems like something that could be proven wrong. I don't see any real fundamental obstacles here. You'd need to do some engineering obviously. But it's not a particularly hard problem. Don't crash into the thing in front of you if it hits the brakes for whatever reason. That about sums up the scope of the issue. There's probably a bit of math involved that tells you the minimum safe distance where emergency braking can still work given a certain speed. If you get humans out of the loop (which the Boring company obviously has not yet done), it's basically a function of how quickly individual pods can react to each other. Which would be measured in nano seconds probably. You should be able to get a pretty decent throughput. The nice thing with small cheap tunnels is that you don't have to squeeze everyone just through one of them because you can have more than one going all over the place. Most subway systems are a compromise on tunnel size where you basically end up with only a few of them because they are so expensive to build. They are literal bottlenecks because lots of people end up being funneled through a handful of stations via a small number of tunnels. By the millions. If you've ever tried to navigate the London underground during rush hour, it's not a pleasant experience. You basically have people shuffling back to back through tunnels and being crammed into railway carriages by the hundreds. The premise of the Boring company is very simple: digging smaller tunnels at scale is going to have economies of scale associated that means you can have vastly more of them for the same money. I agree their execution hasn't really delivered yet. But it still could. Probably waiting/hoping for FSD to solve the problem of routing wasn't the optimal move. But that doesn't invalidate the core premise. The tunnels they've dug aren't that expensive. So that part seems to be valid.

karlgkk 2y ago
> But it's not a particularly hard problem. Don't crash into the thing in front of you It turns out that this is a particularly hard problem. Oh, and if you get it wrong, people will die. In some cases, dozens of people.
- pintxo 2y ago
  But that’s the big safety advantage of pods over railcars. Only a small number of people can die in pods. /s
  - karlgkk 2y ago
    lol yeah although tbf American car fatality rates are pretty bad too
- katbyte 2y ago
  It’s a solved problem for real metros. Automated systems exist the world round. My city has had and automated metro for nearly 40 years. It’s rather easy with rail.
  - karlgkk 2y ago
    > It’s a solved problem for real metros. This isn't a real metro. > My city has had and automated metro for nearly 40 years. Every year, in every country, there are failures that lead to fatalities. They are, thanks to technology, decreasing. > It’s rather easy with rail. It takes hundreds of engineers years to safely design and implement a train control system, and it branches out with complexity. Every year, cascading failures cause serious issues. It sounds easy. It's not.
    - katbyte 2y ago
      In 40 years there has not been a single failure of automation I am aware of leading to a death here in a city of millions. This is a busy metro not some tiny thing with a couple stops 40. Years. So yea it is a solved problem from the perspective of living in an area with a large metro that has been fully automated for as long as I’ve been alive with very few failures and zero of these “serious issues” you think happen. They were able to do it here with 40 year old tech, it should be easier and cheaper to do now And it is easy when you are on rails in a controlled grade separate environment compared to automating cars/whatever Tesla is failing to do with cameras alone And you say it’s not metro but people here are acting like the Tesla loop is “metro” and can compare/be better/cheaper then real metro by “just have multiple tunnels”
infotainment 2y ago
> The premise of the Boring company is very simple: digging smaller tunnels at scale is going to have economies of scale associated that means you can have vastly more of them for the same money. ...so instead of 1 tunnel with a train in it, we could achieve the same throughput with 10 tunnels with single occupancy vehicles. Brilliant! Cost savings achieved! I'm sure the math will just somehow work out that 10 tunnels is cheaper than 1.
- _nalply 2y ago
  The trick to cost saving: stack the tunnels! Exploit the 3D feature of below ground! /s
  - infotainment 2y ago
    You know, I was thinking about how that would actually work, and I just can't imagine it being anything remotely close to efficient. For example, if you were driving on tunnel level 26 (you had to go down there because it's rush hour and the higher levels are jammed up), wouldn't it be insanely annoying to get back to a higher level? Do we have massive spiral ramps connecting each tunnel level? What about interchanges onto other directions, do you need to be on a particular level, or do you need to spiral your way up to Level 15 West Tunnel Expressway Interconnection Point to transfer to Northeast Extended Tunnel Expressway Business Loop 2A?
    - _nalply 2y ago
      Haha, you spent a lot more thought than me!
    - Veedrac 2y ago
      Why would every level have easy and uniform connections to every other level? They are transport connections, not destinations. And 26 levels? Why would you ever need that much capacity?
      - immibis 2y ago
philjohn 2y ago
Listen to "Well There's your Problem" podcast on this. The maths don't math compared to literally any other form of mass underground transit.
stephen_g 2y ago
Let’s take the Elizabeth Line (Crossrail), where they run 24 trains per hour peak (every 2.4 minutes!) with up to 1500 people per train. That’s a theoretical maximum capacity of 36K passengers per hour. Let’s say our four passenger Teslas can be dispatched every 10 seconds into the tunnel. That’s 360 vehicles per hour, four passengers per vehicle, or 1440 passengers per hour. Up the pod size to 20 pax and you still only have 7,200 pax per hour. Halve the safety margin to 5 seconds and you still only have 14.4K per hour, 40% of the capacity of the conventional train. And filling and dispatching 20 people per pod every 5 seconds is a pretty tricky logistics problem!
- jillesvangurp 2y ago
  So, increase the number of tunnels and remove bottlenecks where people are piling up by creating tunnels to where they actually want to go. What would the London underground look like with 100x more tunnels and stations? A lot less busy in each tunnel probably. Plenty of room under London. The issue is the cost of tunneling and building these massively huge stations. Smaller could be a lot cheaper.
  - stephen_g 2y ago
    That would be ludicrously expensive - again, they had that idea at the Boring Company, and it hinged on finding cheaper ways of building tunnels (beyond just making them too small to fit emergency egress). As we've already seen, that never came to be, tunnelling is pretty optimised as it is. With your 100 tunnels you could probably just reach the capacity of the Elizabeth Line (again, just one example) but at 75x the cost...
manuelmoreale 2y ago
> You assert this like it's a fact. But it seems like something that could be proven wrong. I don't see any real fundamental obstacles here. I think it's just a safe conclusion based on some reasonable assumptions. Just to pick one as an example, Wiki tells me a NY subway train is usually 8 to 10 cars. I'll use 10 to make the math easier. They're between 15m to 23m long so I'll go with 20 and that's 200m. Capacity is around 200 people each which gives us 2000 people per train. A model Y is 4.7m long and can seat up to 4 people. To get to 2000 people capacity you then need 500 model Y. 500 Model Y, one after the other in a straight line is 2350m so already to get to the same capacity you need 10x the space without even factoring in the fact you need to add space in beteen each and every one of those 500 cars as a safety measure.
- jillesvangurp 2y ago
  The only reason it's interesting to share farts and bad breath with that many people is that subway tunnels in NY are really expensive to make. They cost many billions to dig and even minor extensions to existing tunnels seem to to turn into multi billion$ projects. And then you need these massive subway stations that also cost billions. Doing things at that scale seems really expensive and ripe for disruption. Your assumption is that there would be just 1 tunnel instead of many. Probably because you are assuming tunnels are super expensive and that that is something that cannot improved. The premise of the Boring company was that they would be able to cut cost by some orders of magnitude by doing things at scale. They haven't yet, obviously. But that doesn't prove the basic premise wrong. Cheap tunnels mean you could have many more tunnels between many more destinations; not all of which need to be super dense cities like New York. Which means you don't have to squeeze millions of people through a single one of them. The cheaper the tunnels, the less the capacity matters. Just add tunnels to scale if things get congested. And of course the model Y is hardly the final answer in pod design. There's no good reason why we can't have a mix of smaller and bigger ones. In fact, using a big lump of an SUV designed for road traffic for this seems not very optimal.
- Veedrac 2y ago
  Note that 2350m is 6 minute headway at a 17mph average subway speed, which isn't at all crazy for a subway. A single-tunnel Boring Loop isn't competing against the 10th busiest subway, though. Even if Boring Loop were competing against New York City Subway, at $2.5B/mi you could build something like 50 parallel lanes at the same cost, and 2350m/50 is only ~50m. Space them out a bit so it's actually driveable and you're probably still ahead with Boring Loop, even assuming the trains are running full (which is not default). Now, if you did invest enough for 50 parallel lanes you clearly wouldn't want to do 50 parallel lanes; they pack awkwardly, don't make sense to centralize that much if you design doesn't force you to, and you go from having a regulatory advantage of being able to build under city roads to a regulatory nightmare of asking to build 50 parallel lanes underground. It makes much more sense to build point-to-point connections out like a road network, and bring in more traditional mass transit where you have particularly busy connections that can't be handled with a reasonable number of lanes.
kmacleod 2y ago
I don't know why you're getting downvoted. I used to work for a PRT (podcar) company and for anything up to a large commuter train or major New York subway, compared seat-mile for seat-mile the networks of small vehicles are just as efficient as most urban transit. And then as a bonus you get no-transfer, direct point-to-point commutes. Even the loading and unloading is comparable between them for stadium event traffic.

karlgkk 2y ago

> But it's not a particularly hard problem. Don't crash into the thing in front of you It turns out that this is a particularly hard problem. Oh, and if you get it wrong, people will die. In some cases, dozens of people.

pintxo 2y ago
But that’s the big safety advantage of pods over railcars. Only a small number of people can die in pods. /s
- karlgkk 2y ago
  lol yeah although tbf American car fatality rates are pretty bad too
katbyte 2y ago
It’s a solved problem for real metros. Automated systems exist the world round. My city has had and automated metro for nearly 40 years. It’s rather easy with rail.
- karlgkk 2y ago
  > It’s a solved problem for real metros. This isn't a real metro. > My city has had and automated metro for nearly 40 years. Every year, in every country, there are failures that lead to fatalities. They are, thanks to technology, decreasing. > It’s rather easy with rail. It takes hundreds of engineers years to safely design and implement a train control system, and it branches out with complexity. Every year, cascading failures cause serious issues. It sounds easy. It's not.
  - katbyte 2y ago
    In 40 years there has not been a single failure of automation I am aware of leading to a death here in a city of millions. This is a busy metro not some tiny thing with a couple stops 40. Years. So yea it is a solved problem from the perspective of living in an area with a large metro that has been fully automated for as long as I’ve been alive with very few failures and zero of these “serious issues” you think happen. They were able to do it here with 40 year old tech, it should be easier and cheaper to do now And it is easy when you are on rails in a controlled grade separate environment compared to automating cars/whatever Tesla is failing to do with cameras alone And you say it’s not metro but people here are acting like the Tesla loop is “metro” and can compare/be better/cheaper then real metro by “just have multiple tunnels”

infotainment 2y ago

> The premise of the Boring company is very simple: digging smaller tunnels at scale is going to have economies of scale associated that means you can have vastly more of them for the same money. ...so instead of 1 tunnel with a train in it, we could achieve the same throughput with 10 tunnels with single occupancy vehicles. Brilliant! Cost savings achieved! I'm sure the math will just somehow work out that 10 tunnels is cheaper than 1.

_nalply 2y ago
The trick to cost saving: stack the tunnels! Exploit the 3D feature of below ground! /s
- infotainment 2y ago
  You know, I was thinking about how that would actually work, and I just can't imagine it being anything remotely close to efficient. For example, if you were driving on tunnel level 26 (you had to go down there because it's rush hour and the higher levels are jammed up), wouldn't it be insanely annoying to get back to a higher level? Do we have massive spiral ramps connecting each tunnel level? What about interchanges onto other directions, do you need to be on a particular level, or do you need to spiral your way up to Level 15 West Tunnel Expressway Interconnection Point to transfer to Northeast Extended Tunnel Expressway Business Loop 2A?
  - _nalply 2y ago
    Haha, you spent a lot more thought than me!
  - Veedrac 2y ago
    Why would every level have easy and uniform connections to every other level? They are transport connections, not destinations. And 26 levels? Why would you ever need that much capacity?
    - immibis 2y ago

philjohn 2y ago

Listen to "Well There's your Problem" podcast on this. The maths don't math compared to literally any other form of mass underground transit.

stephen_g 2y ago

Let’s take the Elizabeth Line (Crossrail), where they run 24 trains per hour peak (every 2.4 minutes!) with up to 1500 people per train. That’s a theoretical maximum capacity of 36K passengers per hour. Let’s say our four passenger Teslas can be dispatched every 10 seconds into the tunnel. That’s 360 vehicles per hour, four passengers per vehicle, or 1440 passengers per hour. Up the pod size to 20 pax and you still only have 7,200 pax per hour. Halve the safety margin to 5 seconds and you still only have 14.4K per hour, 40% of the capacity of the conventional train. And filling and dispatching 20 people per pod every 5 seconds is a pretty tricky logistics problem!

jillesvangurp 2y ago
So, increase the number of tunnels and remove bottlenecks where people are piling up by creating tunnels to where they actually want to go. What would the London underground look like with 100x more tunnels and stations? A lot less busy in each tunnel probably. Plenty of room under London. The issue is the cost of tunneling and building these massively huge stations. Smaller could be a lot cheaper.
- stephen_g 2y ago
  That would be ludicrously expensive - again, they had that idea at the Boring Company, and it hinged on finding cheaper ways of building tunnels (beyond just making them too small to fit emergency egress). As we've already seen, that never came to be, tunnelling is pretty optimised as it is. With your 100 tunnels you could probably just reach the capacity of the Elizabeth Line (again, just one example) but at 75x the cost...

manuelmoreale 2y ago

> You assert this like it's a fact. But it seems like something that could be proven wrong. I don't see any real fundamental obstacles here. I think it's just a safe conclusion based on some reasonable assumptions. Just to pick one as an example, Wiki tells me a NY subway train is usually 8 to 10 cars. I'll use 10 to make the math easier. They're between 15m to 23m long so I'll go with 20 and that's 200m. Capacity is around 200 people each which gives us 2000 people per train. A model Y is 4.7m long and can seat up to 4 people. To get to 2000 people capacity you then need 500 model Y. 500 Model Y, one after the other in a straight line is 2350m so already to get to the same capacity you need 10x the space without even factoring in the fact you need to add space in beteen each and every one of those 500 cars as a safety measure.

jillesvangurp 2y ago
The only reason it's interesting to share farts and bad breath with that many people is that subway tunnels in NY are really expensive to make. They cost many billions to dig and even minor extensions to existing tunnels seem to to turn into multi billion$ projects. And then you need these massive subway stations that also cost billions. Doing things at that scale seems really expensive and ripe for disruption. Your assumption is that there would be just 1 tunnel instead of many. Probably because you are assuming tunnels are super expensive and that that is something that cannot improved. The premise of the Boring company was that they would be able to cut cost by some orders of magnitude by doing things at scale. They haven't yet, obviously. But that doesn't prove the basic premise wrong. Cheap tunnels mean you could have many more tunnels between many more destinations; not all of which need to be super dense cities like New York. Which means you don't have to squeeze millions of people through a single one of them. The cheaper the tunnels, the less the capacity matters. Just add tunnels to scale if things get congested. And of course the model Y is hardly the final answer in pod design. There's no good reason why we can't have a mix of smaller and bigger ones. In fact, using a big lump of an SUV designed for road traffic for this seems not very optimal.
Veedrac 2y ago
Note that 2350m is 6 minute headway at a 17mph average subway speed, which isn't at all crazy for a subway. A single-tunnel Boring Loop isn't competing against the 10th busiest subway, though. Even if Boring Loop were competing against New York City Subway, at $2.5B/mi you could build something like 50 parallel lanes at the same cost, and 2350m/50 is only ~50m. Space them out a bit so it's actually driveable and you're probably still ahead with Boring Loop, even assuming the trains are running full (which is not default). Now, if you did invest enough for 50 parallel lanes you clearly wouldn't want to do 50 parallel lanes; they pack awkwardly, don't make sense to centralize that much if you design doesn't force you to, and you go from having a regulatory advantage of being able to build under city roads to a regulatory nightmare of asking to build 50 parallel lanes underground. It makes much more sense to build point-to-point connections out like a road network, and bring in more traditional mass transit where you have particularly busy connections that can't be handled with a reasonable number of lanes.

kmacleod 2y ago

I don't know why you're getting downvoted. I used to work for a PRT (podcar) company and for anything up to a large commuter train or major New York subway, compared seat-mile for seat-mile the networks of small vehicles are just as efficient as most urban transit. And then as a bonus you get no-transfer, direct point-to-point commutes. Even the loading and unloading is comparable between them for stadium event traffic.