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It's apparent through a lot of boring company press releases the tunnels are intended for essentially cars temporarily put onto skates in tunnels. So then why

It's apparent through a lot of boring company press releases the tunnels are intended for essentially cars temporarily put onto skates in tunnels. So then why not a high speed train instead of individual vehicles? You would think the capital cost of a tunnel over it's lifetime (100+ years going by the NYC subways) is not substantial compared with magnitudes more in individual vehicle operating costs. Not to mention trains have much higher throughput, energy efficiency, less worry over spacing via stopping distance etc over individual propulsion methods, and airports are pretty bursty in terms of traffic volume. The answer seems pretty clear with the disdain Musk expresses of sharing public space with the average person. https://www.wired.com/story/elon-musk-awkward-dislike-mass-transit/ https://www.wired.com/story/elon-musk-awkward-dislike-mass-t... (which for me, also explains the obsession with Mars as some sort of refuge from disaster on Earth) He's clearly focused on more cars as the solution to the urban issues that cars are causing.

cozzyd 8y ago
Yeah, why not tether the "skates" together into a train? Boarding individual 8-16 person vehicles seems like a major chokepoint.
- rory096 8y ago
  The intent is the opposite - having individual cars allows you to parallelize ingress/egress, as long as you have pulloffs at stations (and sufficient elevator capacity). The decrease in trip time from making every trip express (instead of stopping at every station for the fraction of passengers who want to get off) offsets the smaller car/train capacity.
JackCh 8y ago
Maybe Musk having some agoraphobic bias is the root cause. Or maybe it's because Tesla doesn't sell trains.
agildehaus 8y ago
> So then why not a high speed train instead of individual vehicles? This is meant to evolve into a citywide transportation system where you choose your destination at the outset. Each pod can navigate itself, switch tunnels, and wind up closer to your destination than a subway could ever hope to as there will be far more stops (multiple thousands across the city instead of < 500). Clearly the airport express route is meant to be the beginning of something much larger. Trains would not make sense for such a system.
- ComradeTaco 8y ago
  Building underground interchanges that include complete grade separation would entail building cloverleaf interchanges underground. Cloverleaf interchanges usually cost somewhere from 500 million USD to 2 billion USD above ground.
- cozzyd 8y ago
  Such a system would either be very low throughput or just as bogged down as the roads. Individual itineraries imply low-occupancy vehicles (because how many people from your starting point will go to the same out of thousands of destinations?). If you assume an optimistic 4 people per vehicle with an optimistic 5 second interval between vehicles (which is probably not safe at the high speeds due to the frequent merges), that gives you ~50 people / minute / lane, or 3000 per hour. A single CTA 8-car train at crush capacity (admittedly uncomfortable) can carry nearly 1000 people. Now a frequent system with high occupancy vehicles and transfers could work, but that's the same thing as a subway.
  - tokipin 8y ago
    The key is that this system can operate in 3D. You can have bundles of tunnels where you need higher throughput, and greater demand can just be met with more tunnels. The focus on small tunnels/cars as the core technology is part of this, since it makes it easier to reach "mass production" scales.
    - cozzyd 8y ago
rsynnott 8y ago
> The answer seems pretty clear with the disdain Musk expresses of sharing public space with the average person. Designing a transport system around some guy's phobias seems like a bad idea. The system described only has a 2k/hour peak capacity. It's unusable as real public transport.

cozzyd 8y ago

Yeah, why not tether the "skates" together into a train? Boarding individual 8-16 person vehicles seems like a major chokepoint.

rory096 8y ago
The intent is the opposite - having individual cars allows you to parallelize ingress/egress, as long as you have pulloffs at stations (and sufficient elevator capacity). The decrease in trip time from making every trip express (instead of stopping at every station for the fraction of passengers who want to get off) offsets the smaller car/train capacity.

JackCh 8y ago

Maybe Musk having some agoraphobic bias is the root cause. Or maybe it's because Tesla doesn't sell trains.

agildehaus 8y ago

> So then why not a high speed train instead of individual vehicles? This is meant to evolve into a citywide transportation system where you choose your destination at the outset. Each pod can navigate itself, switch tunnels, and wind up closer to your destination than a subway could ever hope to as there will be far more stops (multiple thousands across the city instead of < 500). Clearly the airport express route is meant to be the beginning of something much larger. Trains would not make sense for such a system.

ComradeTaco 8y ago
Building underground interchanges that include complete grade separation would entail building cloverleaf interchanges underground. Cloverleaf interchanges usually cost somewhere from 500 million USD to 2 billion USD above ground.
cozzyd 8y ago
Such a system would either be very low throughput or just as bogged down as the roads. Individual itineraries imply low-occupancy vehicles (because how many people from your starting point will go to the same out of thousands of destinations?). If you assume an optimistic 4 people per vehicle with an optimistic 5 second interval between vehicles (which is probably not safe at the high speeds due to the frequent merges), that gives you ~50 people / minute / lane, or 3000 per hour. A single CTA 8-car train at crush capacity (admittedly uncomfortable) can carry nearly 1000 people. Now a frequent system with high occupancy vehicles and transfers could work, but that's the same thing as a subway.
- tokipin 8y ago
  The key is that this system can operate in 3D. You can have bundles of tunnels where you need higher throughput, and greater demand can just be met with more tunnels. The focus on small tunnels/cars as the core technology is part of this, since it makes it easier to reach "mass production" scales.
  - cozzyd 8y ago

rsynnott 8y ago

> The answer seems pretty clear with the disdain Musk expresses of sharing public space with the average person. Designing a transport system around some guy's phobias seems like a bad idea. The system described only has a 2k/hour peak capacity. It's unusable as real public transport.