5 ms·

At a 2 seconds clearance between vehicles, the Tesla system at peak capacity of 4 passengers will move 2 people per second. So it's equivalent with a subway tra

At a 2 seconds clearance between vehicles, the Tesla system at peak capacity of 4 passengers will move 2 people per second. So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. That kind of frequency is typical for some longer haul train links, airport trains with underground sections like the RER etc. Of course, there are other factors that preclude running Loop at 2s frequency, like station capacity and ensuing bottlenecks on ramps etc., but bear in mind there is no comparison between a train filled at crush capacity, with most people standing and smelling someone else's armpit, that you have to wait for a quarter of an hour, vs a leather seated car that takes you point to point to your destination without stopping at any intermediary station. The point is, they are very different systems that don't compete against each other. If you need a subway and have the money for a subway, by all means, build a subway. Loop competes with light rail, and it says it can do better than most of the light rail systems in operation, at least in the US. Both its claimed pphpd and per mile cost are sufficient to be financially competitive, to the point that it can attract private capital and generate profits. And the pphpd they demonstrated, of nearly 5000, was achieved with Tesla cars. If they manage to introduce 8-12 seaters and cracks self driving in the tunnels (a much simpler problem then full on road self driving) than it could compete with many of the less congested subway networks. It seems very irrational not to let them demonstrate what they claim, as long as they are using their own money. It's transport capacity that does not compete with other transit options and does not capture significant urban real estate.

eesmith 2y ago
> the Tesla system at peak capacity of 4 passengers will move 2 people per second. Your analysis is incomplete. A moving sidewalk on the airport can move far more than 2 people per second, and needs no driver. Where is the call to revive that form of travel descried in Heinlein's "The Roads Must Roll" and Asimov's "The Caves of Steel"? You are missing speed, and acceleration, and load time. > So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. Well-frequented London lines run with something like 2-3 minute intervals, not 16 minute intervals. And you can easily carry luggage with you, push a stroller, or roll your wheelchair on in. > and smelling someone else's armpit Yes, it appeals to rich people who want to use their money to avoid even minor irritations, and don't want to pay taxes to support mass transit that helps everyone. (From the link, "some press and discussion around the Loop figures it as more of a luxury option: something that casinos can comp for high rollers, that will spare people dealing with the general disaster of getting around the strip".) But that means having an alternative for us poor stinking masses. The Loop is not that solution. By the time the subway system gets to the crowd level you describe, a Loop-type system would be well over capacity. You'll be stuck in a line waiting for the next Tesla to arrive, surrounded by stinky people. > was achieved with Tesla cars. If they manage to introduce 8-12 seaters Why are they using Teslas? As the article notes, "due to their larger seating capacity and faster boarding/deboarding, the Loop would likely achieve a higher capacity if they just shifted operations entirely to the Club Cars". With "four rows of seats", it's likely something like https://www.clubcar.com/en-us/commercial/transport/villager-8 https://www.clubcar.com/en-us/commercial/transport/villager-... which says "A long time classic on resorts, the Villager 8 moves up to eight passengers in a single trip and can replace expensive vans. Yet it also travels narrow areas not accessible to conventional vehicles." It seems they could easily increase capacity now by simply changing vehicle type. Also, since the capacity numbers were achieved with Tesla cars, that means it excluded the GEM carts which the article says is uses for people with wheelchairs. That suggests the "nearly 5000" number does not include people with mobility issues, which would need to be supported under ADA requirements. At peak capacity, even a small disturbance can greatly reduce flow. > It seems very irrational not to let them demonstrate what they claim The page says their claim is that the fully expanded system will target only 90k passengers per day. It seems very irrational to not draw conclusions from that.
- tlb 2y ago
  Travel speed matters too. At non-peak times, when queues are short, going 100 kph will give much shorter commute times than moving sidewalks (5 kph) or club cars (25 kph).
  - eesmith 2y ago
    Yes, travel speed is the first part of 'You are missing speed, and acceleration, and load time.' :) In those SF stories, moving sidewalks were more then 5kph. "The Caves of Steel" had parallel strips, each at a faster speed. Quoting https://archive.org/details/robotnovels0000isaa/page/10/mode/2up?q=moving https://archive.org/details/robotnovels0000isaa/page/10/mode... : "He stepped from strip to strip with the ease of a lifetime’s practice. Children learned to “hop the strips” as soon as they learned to walk. Baley scarcely felt the jerk of acceleration as his velocity increased with each step. He was not even aware that he leaned forward against the force. In thirty seconds he had reached the final sixty mile-an-hour strip and could step aboard the railed and glassed-in moving platform that was the expressway.'" 60 mph is 100 kph. "The Roads Must Roll" had a similar design. The first version (quoting https://archive.org/details/pastthroughtomor0000robe/page/42/mode/2up?q=belt https://archive.org/details/pastthroughtomor0000robe/page/42... ) was: "based on the ore belt conveyors of ten years earlier. The fastest strip moved only thirty miles per hour, and Was quite narrow, for no one had thought of the possibility of locating retail trade on the strips themselves. Nevertheless, it was a prototype of social pattern which was to dominate the American scene within the next two decades—neither rural, nor urban, but partaking equally of both, and based on rapid, safe, cheap, convenient transportation." The first high-speed road went 80 mph. https://archive.org/details/pastthroughtomor0000robe/page/44/mode/2up?q=belt https://archive.org/details/pastthroughtomor0000robe/page/44... . If we look to the moving sidewalks of now to understand the future dreams of the 1950s, then we should of course also look at the PRT systems of now to understand the problems with the Las Vegas loop.
- cornholio 2y ago
  The idea to use moving walkways is completely fantastical and has no bearing on this discussion. An automated walkway is just a (poor, slow and very expensive to build and maintain) transportation device, comparable to an electric bus. But electrics buses are not, by themselves, a solution to traffic because they must share the congested grid with all other above ground transport modes. Even if you would have the money required to build a mile of bidirectional walkways and the necessary enclosure (without which they would break down at the first rain), you still don't have the required right of way. And if you do get it, you would be completely harebrained to employ it for this project to double the walking speed of travelers, instead of, say, a BRT system, a bike or electric scooter lane etc. that are in every way superior solutions. Loop is comparable with subways because in each case we are talking about dedicated infrastructure that does not compete in the fixed sum struggle for street space. And it's primarily a tunnel network that has very high per tunnel theoretical throughput, see for example the London subways. The exact vehicle mix that's revenue maximizing for that infrastucture is still to be determined. It could remain a luxury taxi service or it could well evolve into a rubber wheeled metro. Probably they will do both at the same time. > Why are they using Teslas? Because it's the minimal viable product that allow them to meet city milestones and continue to evolve the system. Developing a completely new and custom vehicle for passenger transport is a massive risk, money and time sink that will be justified only later. Golf carts won't cut it for a variety of reasons.
Gud 2y ago
>At a 2 seconds clearance between vehicles, the Tesla system at peak capacity of 4 passengers will move 2 people per second. So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. That kind of frequency is typical for some longer haul train links, airport trains with underground sections like the RER etc. Typical where? Any well functioning subway system I’ve been on has a much higher frequency than that. Every 3-5 minutes.
- cornholio 2y ago
  " ...typical for some longer haul train links, airport trains with underground sections like the RER etc." I am certainly aware of the frequency most subways run at, that's why I clearly defined a comparable system, and later in the post underlined that Loop is not a direct competitor with subways but with above ground light rail. I have no idea why people get triggered so easily and jump to type out a response without finishing reading the post - or, in this case, the sentence - they are replying to. It must have something to do with the compressed attention spans that come with smartphones.
immibis 2y ago
> So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. The Berlin subway typically runs 4-minute and 5-minute intervals (except at the periphery) and they're seeking to upgrade it. Some more advanced systems in the world run at 2-minute or even 90-second intervals. So, by your calculation, the tunnel has the capacity of 1/4 of an old subway and 1/10 of a cutting-edge subway.
- cornholio 2y ago
  > So, by your calculation, the tunnel has the capacity of 1/4 of an old subway and 1/10 of a cutting-edge subway. Yes, if you use it with 4 passengers Model Ys spaced 2 seconds apart. There is nothing in principle that precludes using 8-16 minibuses (2-4x increase in raw tunnel capacity) or even linking multiple such cars to form a train, building essentially a rubber tired subway. The point is, the tunnel diameter is not limiting throughput. It's a flexible system where you can mix multiple types of vehicles with various density, comfort, price points, number of stops to destination etc. In the extreme, you can have multiple station designs, so that a limited number of larger stations can handle the multi-cart trains, on a fixed schedule and stopping in every such large station, while a small number of lower capacity stations and spurs can handle the luxury point to point cab service in Model Ys or similar that will take you from your hotel to you casino or airport. Essentially, Loop has its own private transport infrastructure and they will search a mix of vehicle types and station designs and locations that will maximize revenue and infrastructure utilization. It's mind boggling that some call it a failure when it's only beginning to create the system and unlock the network effects.
katbyte 2y ago
The metro in my city runs automated trains every 2-3 min at rush hour (and I think it can run them every 99s if needed) there is zero possibly the joke of a system using Tesla could keep up And sure enough 5000 ppl is a far cry from 25,000 it’s rated for with mark 2 trains

eesmith 2y ago

> the Tesla system at peak capacity of 4 passengers will move 2 people per second. Your analysis is incomplete. A moving sidewalk on the airport can move far more than 2 people per second, and needs no driver. Where is the call to revive that form of travel descried in Heinlein's "The Roads Must Roll" and Asimov's "The Caves of Steel"? You are missing speed, and acceleration, and load time. > So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. Well-frequented London lines run with something like 2-3 minute intervals, not 16 minute intervals. And you can easily carry luggage with you, push a stroller, or roll your wheelchair on in. > and smelling someone else's armpit Yes, it appeals to rich people who want to use their money to avoid even minor irritations, and don't want to pay taxes to support mass transit that helps everyone. (From the link, "some press and discussion around the Loop figures it as more of a luxury option: something that casinos can comp for high rollers, that will spare people dealing with the general disaster of getting around the strip".) But that means having an alternative for us poor stinking masses. The Loop is not that solution. By the time the subway system gets to the crowd level you describe, a Loop-type system would be well over capacity. You'll be stuck in a line waiting for the next Tesla to arrive, surrounded by stinky people. > was achieved with Tesla cars. If they manage to introduce 8-12 seaters Why are they using Teslas? As the article notes, "due to their larger seating capacity and faster boarding/deboarding, the Loop would likely achieve a higher capacity if they just shifted operations entirely to the Club Cars". With "four rows of seats", it's likely something like https://www.clubcar.com/en-us/commercial/transport/villager-8 https://www.clubcar.com/en-us/commercial/transport/villager-... which says "A long time classic on resorts, the Villager 8 moves up to eight passengers in a single trip and can replace expensive vans. Yet it also travels narrow areas not accessible to conventional vehicles." It seems they could easily increase capacity now by simply changing vehicle type. Also, since the capacity numbers were achieved with Tesla cars, that means it excluded the GEM carts which the article says is uses for people with wheelchairs. That suggests the "nearly 5000" number does not include people with mobility issues, which would need to be supported under ADA requirements. At peak capacity, even a small disturbance can greatly reduce flow. > It seems very irrational not to let them demonstrate what they claim The page says their claim is that the fully expanded system will target only 90k passengers per day. It seems very irrational to not draw conclusions from that.

tlb 2y ago
Travel speed matters too. At non-peak times, when queues are short, going 100 kph will give much shorter commute times than moving sidewalks (5 kph) or club cars (25 kph).
- eesmith 2y ago
  Yes, travel speed is the first part of 'You are missing speed, and acceleration, and load time.' :) In those SF stories, moving sidewalks were more then 5kph. "The Caves of Steel" had parallel strips, each at a faster speed. Quoting https://archive.org/details/robotnovels0000isaa/page/10/mode/2up?q=moving https://archive.org/details/robotnovels0000isaa/page/10/mode... : "He stepped from strip to strip with the ease of a lifetime’s practice. Children learned to “hop the strips” as soon as they learned to walk. Baley scarcely felt the jerk of acceleration as his velocity increased with each step. He was not even aware that he leaned forward against the force. In thirty seconds he had reached the final sixty mile-an-hour strip and could step aboard the railed and glassed-in moving platform that was the expressway.'" 60 mph is 100 kph. "The Roads Must Roll" had a similar design. The first version (quoting https://archive.org/details/pastthroughtomor0000robe/page/42/mode/2up?q=belt https://archive.org/details/pastthroughtomor0000robe/page/42... ) was: "based on the ore belt conveyors of ten years earlier. The fastest strip moved only thirty miles per hour, and Was quite narrow, for no one had thought of the possibility of locating retail trade on the strips themselves. Nevertheless, it was a prototype of social pattern which was to dominate the American scene within the next two decades—neither rural, nor urban, but partaking equally of both, and based on rapid, safe, cheap, convenient transportation." The first high-speed road went 80 mph. https://archive.org/details/pastthroughtomor0000robe/page/44/mode/2up?q=belt https://archive.org/details/pastthroughtomor0000robe/page/44... . If we look to the moving sidewalks of now to understand the future dreams of the 1950s, then we should of course also look at the PRT systems of now to understand the problems with the Las Vegas loop.
cornholio 2y ago
The idea to use moving walkways is completely fantastical and has no bearing on this discussion. An automated walkway is just a (poor, slow and very expensive to build and maintain) transportation device, comparable to an electric bus. But electrics buses are not, by themselves, a solution to traffic because they must share the congested grid with all other above ground transport modes. Even if you would have the money required to build a mile of bidirectional walkways and the necessary enclosure (without which they would break down at the first rain), you still don't have the required right of way. And if you do get it, you would be completely harebrained to employ it for this project to double the walking speed of travelers, instead of, say, a BRT system, a bike or electric scooter lane etc. that are in every way superior solutions. Loop is comparable with subways because in each case we are talking about dedicated infrastructure that does not compete in the fixed sum struggle for street space. And it's primarily a tunnel network that has very high per tunnel theoretical throughput, see for example the London subways. The exact vehicle mix that's revenue maximizing for that infrastucture is still to be determined. It could remain a luxury taxi service or it could well evolve into a rubber wheeled metro. Probably they will do both at the same time. > Why are they using Teslas? Because it's the minimal viable product that allow them to meet city milestones and continue to evolve the system. Developing a completely new and custom vehicle for passenger transport is a massive risk, money and time sink that will be justified only later. Golf carts won't cut it for a variety of reasons.

Gud 2y ago

>At a 2 seconds clearance between vehicles, the Tesla system at peak capacity of 4 passengers will move 2 people per second. So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. That kind of frequency is typical for some longer haul train links, airport trains with underground sections like the RER etc. Typical where? Any well functioning subway system I’ve been on has a much higher frequency than that. Every 3-5 minutes.

cornholio 2y ago
" ...typical for some longer haul train links, airport trains with underground sections like the RER etc." I am certainly aware of the frequency most subways run at, that's why I clearly defined a comparable system, and later in the post underlined that Loop is not a direct competitor with subways but with above ground light rail. I have no idea why people get triggered so easily and jump to type out a response without finishing reading the post - or, in this case, the sentence - they are replying to. It must have something to do with the compressed attention spans that come with smartphones.

immibis 2y ago

> So it's equivalent with a subway train at crush capacity running every 1000 seconds or 16 minutes. The Berlin subway typically runs 4-minute and 5-minute intervals (except at the periphery) and they're seeking to upgrade it. Some more advanced systems in the world run at 2-minute or even 90-second intervals. So, by your calculation, the tunnel has the capacity of 1/4 of an old subway and 1/10 of a cutting-edge subway.

cornholio 2y ago
> So, by your calculation, the tunnel has the capacity of 1/4 of an old subway and 1/10 of a cutting-edge subway. Yes, if you use it with 4 passengers Model Ys spaced 2 seconds apart. There is nothing in principle that precludes using 8-16 minibuses (2-4x increase in raw tunnel capacity) or even linking multiple such cars to form a train, building essentially a rubber tired subway. The point is, the tunnel diameter is not limiting throughput. It's a flexible system where you can mix multiple types of vehicles with various density, comfort, price points, number of stops to destination etc. In the extreme, you can have multiple station designs, so that a limited number of larger stations can handle the multi-cart trains, on a fixed schedule and stopping in every such large station, while a small number of lower capacity stations and spurs can handle the luxury point to point cab service in Model Ys or similar that will take you from your hotel to you casino or airport. Essentially, Loop has its own private transport infrastructure and they will search a mix of vehicle types and station designs and locations that will maximize revenue and infrastructure utilization. It's mind boggling that some call it a failure when it's only beginning to create the system and unlock the network effects.

katbyte 2y ago

The metro in my city runs automated trains every 2-3 min at rush hour (and I think it can run them every 99s if needed) there is zero possibly the joke of a system using Tesla could keep up And sure enough 5000 ppl is a far cry from 25,000 it’s rated for with mark 2 trains