- Smaller diameter tunnels. 14' is suggested. This is slightly larger than the deep London Tube lines.
- Electrically powered TBMs. Those exist. However, often the business end of the machine is hydraulically powered. Musk is probably thinking of going all electric, at least for the cutter head. After all, he has lots of experience with high-torque electric motors.
- Do cutting and tunnel ring assembly simultaneously. Some TBMs already do that. Those exist; they're called double-shielded TBMs.
Issues glossed over:
- Soil variability. Very different techniques are required for different soils. Sometimes the soil has to be "conditioned", adding something to make it solid enough it can be drilled through. This is the biggest practical problem in tunneling. Too much water is the usual problem.
- The back end. TBMs are long machines. The front end does cutting and ring assembly. The back end, which can be several hundred feet long, is mostly material handling. There's usually a two-track narrow gauge railroad behind the TBM, carrying ring segments forward and dirt backwards. It's constantly being extended with new track sections. That's part of the TBM's job.
Here's a good overview of TBMs design, from Machine Design.
The largest part of the problem to solve here for the US is not the technology of tunneling. It's the process of engineering and building infrastructure like this that seems to become way more expensive in the US compared to places like Spain. I do believe he could reduce costs by vertically integrating the whole thing. But then we should ask why don't we do that anyway?
Sure. Why didn't we have electric cars before tesla? Why didn't Boeing or Lockheed Martin make reusable rockets?
Alan Kay said something recently that has been bouncing around my head for the past few days. He said that many people think darwinian processes (like the economy) optimize. "One my degrees is in molecular biology, and I can tell you, any biologist would say they're absolutely not optimized. The whole point is to fit into some niche in an environment. And if the environment isn't the right kind of environment evolution isn't going to give you something interesting".
In the context of the economy, if there's no innovation, and not enough competition, and no new players entering a market, I don't think its all that surprising that the existing companies might stop reaching to be more efficient.
It seems strange to think that companies would leave money on the table, but in older industries I think this is exactly what happens. The money just requires too much organizational churn for their corporate appetite.
The more I think about organizations the more I they seem to be the key players preventing change to me. (Which is not necessarily a bad thing)
Business says: We had this great idea, now let's freeze everything in time and let's make money of this snapshot forever, because who knows when we'll find gold again.
Entertainment industry likes to do that especially.
Darwinian processes are near-perfectly optimized ... for an extremely local maximum. Once there, they fail to make jumps to much better nearby maxima.
If you look at a somewhat larger scale, where there are better maxima available, then the correct conclusion is that they are absolutely not optimized.
A great example of this is me; I'm pretty amazing; I can move around my environment, make a living to a sufficient degree to cover costs of food and shelter, and somehow even have a fiancée and manage to keep another organism alive & fed. However I'm not an expert at everything, I'm pretty bad at most sporting based things (even compared to other, existing humans; not some theoretical concept of perfection), and I spend about a third of my life doing nothing (sleeping), despite this not necessarily being required (e.g. Dolphins can sleep half their brain at a time, allowing them to avoid this inefficient downtime).
Somewhat related: it was interesting when my kids were born; they both had to be C-sectioned. I asked the obstetrician about it, and yes, bigger heads are becoming more and more common because mother+child no longer just die when they do occur. We really are removing selection pressures!
There's a huge difference between "exploit in the now" and "exploit, but still be viable in a billion+ years".
Von Braun originally proposed reusable boosters, although he had in mind a parachute system with a water splashdown. A recovery system for the Saturn V was considered, but it would have added time to the schedule, and the "man/moon/decade" goal would have been at risk.
I'm not sure you are accepting the basic principle, which is that evolution is not in any way optimization (not that the evolutionary process is not "optimized").
See something like https://en.wikipedia.org/wiki/Fisherian_runaway
Also Giuseppe Longo's work on randomness as a cause of organizational complexity in evolution: http://montevil.theobio.org/en/system/files/articlepdf/Longo...
It's only when the environment changes (rise of mammals post dinosaur-extinction) or the organisms themselves change environment (Darwin's finches) that you get the rapid rates of evolution to find the new optimumm.
Some obvious analogies of these two situations in tech are the rise of the Internet (Microsoft did change, but struggled), and the rise of the smartphone (Apple came from nowhere to a position of dominance).
Mostly because batteries sucked. Small electronics drove most of the research to improve them.
I guess Tesla vehicles are market leading in several ways, but they aren't a generation ahead of what anyone else can do or anything like that.
But sure, no one is out there doing anything other than Tesla.
And I think I am giving credit where credit is due. Battery research made a lot of progress, Tesla used the resulting batteries to make nice electric vehicles. I mean, they have a battery partner and all that jazz.
This is probably true, but it's also deeply heretical for believers in market efficiency.
A public transportation network's usefulness is roughly quadratic in proportion to its size, because it needs to cover both your origin and your destination. A small subway system is nearly useless, because even people who live or work near it probably don't live and work near it. You can mitigate this to an extent with busses, taxis, letting people park at stations, etc., but there's still a lot of friction.
By carrying cars, these tunnels will act as an extension of the road network, which almost certainly covers your origin and destination already. The tunnel part doesn't need to serve the ends, it just needs to exist somewhere in the middle to be useful.
If you build one subway line, it's pretty much "great, let's finish the system so we can have something useful." If you build one Boring Tunnel, it would be immediately useful for anyone whose car trips are vaguely in that direction.
I'm really skeptical it'll all work out, but I don't think it should be thought of as a lame subway.
Unfortunately, they don't allow it during rush hour due to space constraints, so it's not nearly as useful as it could be.
Because with trains you never build just a tunnel - there are train stations, escalators leading in and out, ticketing booths/machines, electrical work to power all that fun stuff, connectors to existing depots so that maintenance workers can come and service the cars and the engines.
His idea is closer to Madrid, which has dug tunnels to relieve the city streets of the traffic. The tunnels themselves are very unassuming and look like onramps and underground parking garage entrances.
Everything about Musk's idea seems absolutely terrible. If America had better trains and subways, it could move massive amounts of people. Train automation is a solved problem, and currently implemented in cities around the world. There is absolutely no possible way in any reality where individual car/pod transport could even approach the capacity of real mass transit:
Americans need to get over our wasteful individualism, our "alone time" in cars and realize you can read a book, watch a movie or do something not involving driving on real public transport. Buses need to stop being just a means of transport for the poor.
In most European cities, if you get off at train station, you're in the midst of (or very close to) the city center, office locations, touristy walking sites and plenty of choices for retail or food.
In the US once you get off at the train station, well, you're at the train station, and now need a car to go anywhere you actually need to go. NYC and SF are likely to be the only exception - train stations as close as LA or San Jose are fairly sparse and have limited connections.
You can run the fastest most frequent train you can handle, and California in fact is building one between Borden and Corcoran, but the "step 2" in US cities generally involves getting a car.
EDIT: embellishment due to baq, this tends to be true of cities which developed before the car revolution of the 50's and 60's. For example, my city has a pretty poor average walkability score, but for where I live in the city core, it is very walkable since it is the older part of the city.
This lesson seems to have been lost for some reason but infrastructure is to be built first, destinations second. Much of the New York City Subway system, like in the Bronx, was built through farmland. Once the infrastructure was built, destinations (dense residential) was built. It has to work that way. It's not practical to expect there to be any destinations available when the subway opens- people need a few decades to rearrange themselves.
Portland should probably join that list.
Depends what his goal is. Currently getting from A to B in a car at a certain time involves traffic jams.
If his goal is to get from A to B most efficiently in a car then it's one of the best ideas.
If his goal is get people from A to B via any mode of transport, perhaps trains. But he owns a car company, so that's not exactly in his interest.
Also with cars it's truly A to B. Not A to subway/carpark, wait, travel, walk to B.
That's why public mass transport was created and was so successful in the big cities. US big automotive destroyed most of this working infrastructure in the last century (E.g. Los Angeles, Houston, ...) but it's still cheaper to build mass transport than to support individual transport. Just ask a New Yorker or a foreigner.
Tunnels are a hazard for individual traffic. That's why pods do help. But trains are still preferred.
It's a good alternative idea to build long range tunnels. He is right. But the focus needs to be mass transport, not individual. It's a matter of costs.
You could rent your car back to the system to use as a lounge for people who want to travel but didn't bring a car to get on the network. Saves you parking costs, maybe an operator could work out paying you for that.
But for big cities trains are much better and cheaper.
Tunnels are great parking structures. Cars on sleds provide a great interface to said parking structure. Heck, NYC has automated parking structures with car elevators and sleds. The only imagination required is not having to dig a big hole down to the depth of the lowest level of the garage first.
Another problem is that all those people have to walk to and from the end station.
A "packet switched" system of sending individual cars at high speed solves both those problems, and going just by my gut feel, should have a quite high throughput too.
Then I sat at an intersection one day and counted how many individuals were being moved through two lanes of regular car traffic vs how many came through on the light rail.
I was shocked by how inefficient regular traffic is.
So now MY gut feel is that without any technological breakthrough, this sort of system would already be starting with an order of magnitude disadvantage: which is to say, shockingly inefficient compared to allready available technology and solutions...
People are walking from the station to these giant office towers in central London. The walk from the Tube station to the office must only take 5-10 minutes, total. My gut feeling says the throughput won't be high specifically because you'll have 800 or so people trying to get out at the same place at roughly the same time.
Where mass transit struggles is in getting people from one arbitrary spot to another at an arbitrary time.
There is a delay between each car which after 20 cars really adds up.
How would that work? Now it's true that there won't be any delays caused by drivers not paying attention, but unless the cars will go 125 mph with only a couple meters of space between them (eep!) the cars will require a non-zero delay "off the line" to allow them to spread out as they gain speed.
How fast they can fork and merge is more interesting, and I dare not have an opinion about that.
I think in the original video, they showed a pod with a group of commuters.
Furthermore, a solution that leverages personal vehicles is slightly more viable for a private sector company. Telsa can continue to promote their car sales without that having a negative effect on the Boring Company.
This idea that a company can replace our entire existing infrastructure with a train/bus system is just purely impractical. There is the solution that seems the most obvious (current public transit), and then there is the one that is actually viable from a business perspective.
I don't get it, where does that come from anyway? I mean America's mostly a country of immigrants; most inhabitants' forefathers, only a couple generations ago, abandoned everything they know to build up a new life. If that's not change, then IDK what is.
I think that at one point it's not about what they want - having the option even to drive anywhere is a luxury a lot of people don't have - it's what's practical. Driving in New York isn't practical, so people take the tube - regular services, high capacity, etc. There's no way a tunnel system with individual cars, which will have a much lower capacity than a regular road, will be able to compete, neither on cost nor capacity.
Of course, if you're rich then it doesn't matter. I'm sure it'll work in SF, where there should be plenty of people that can afford it.
The best answer I have: the more people are individualistic, the more difficult it is for them to coordinate. Big changes like fundamental infrastructure require collective buy-in, and when you have lots of self-interested individuals who stand to gain by introducing friction into the process, costs skyrocket.
The alternative ends of the spectrum (it's not 1D) of that is more social people (dream utopia, I don't know where it exists, if at all) and more authoritarian control (easiest way to coordinate people is to have someone unilaterally decide for them).
That's an excellent answer and I think you are right. Car culture is a big deal in the US and I think the perceived independence it represents is part of the reason why.
* replace tipping with a minimum wage which helping working people get out of poverty
* make checks obsolete
> Driving in New York isn't practical, so people take the tube
The what now? I think you'll find it's actually called le Métropolitain
- Eliminate small coins
- Move to metric in a practical sense rather than just official
Uh? What? Please explain - are you expecting everything to go fine the first time, because in the history of the world, that almost never happens.
The tunnels obviously don't make sense in places that have well established train systems, but a lot of places don't have that. Often in America, the only 'practical' way to get around is using a personal vehicle.
The tunnels themselves are very unassuming
Ventilation, as a very critical entity, comes to mind. Also safety features are extremely critical. I live in a country with lots of tunnels and essentially every longer auto tunnel has additional tubes that are under pressure, for example. That's required if you suddenly have a burning vehicle in the middle of a narrow tube.
While car tunnels don't need to be sexy from an optical perspective there's a ton of necessary infrastructure and safety features, which aren't immediately obvious.
Maybe this changes when we all go electric, but I really don't see that happening anytime soon.
For what its worth, it hints that those sleds will also become public transit platforms as well - "if one adds a vacuum shell, it is now a Hyperloop pod" - but Musk will want to call it something cool like an Urban Hyperloop instead of just a subway.
So this is something I've been trying to address all thread, so excuse me picking your comment.
You can only create a public transit platform by having _dedicated_ infrastructure. We know this because cities like London and Paris (and not-so-big Vancouver) all have mostly-to-fully automated trains with 90-second headways between each train at rush hour. This basically means that if once a train pulls out of the station, the next one pulls in mere seconds later. These trains are usually packed to the gills. Even one single-occupancy vehicle would decrease the overall efficiency of that system.
Heck, you can create a tunnel in each which sled contains one bus and it'd still be less efficient than the London Tube because the whole thing will take up more space, physically (these trains squeeze in every last passenger). This is what Seattle tried to do with the downtown bus tunnel and they're evicting all the buses there in favor of light rail.
I think it will always make sense for subway trains in dense city cores, but I think the discussion about dedicated rapid transit is hampered in more suburban areas because of the whole notion that we have to fit in cars into rapid transit corridors, or else it's not worth it. But this ends up making buses less reliable and gives them their crappy reputation (see: https://en.wikipedia.org/wiki/Bus_bunching).
Grade-separation is absolutely necessary for good rapid transit.
It would be interesting I guess if they combined it with the Hyperloop concept, board the tube system in the city, transition to a (cheaper?) above-ground vacuum tunnel system at a transit station.
But it's all very science-fiction and, if anything, it's not going to be cheap. Like, at all.
At least it's a commercial project, not something a government has to pay for.
It may be expensive - but you only have to build each tunnel once.
There's a startup that got some hype recently for flying an electric airplane between London and Paris - when as someone commented on the HN story  you can just take the Eurostar through the tunnel - which is electric and takes just as long and doesn't cost any more.
Because people have opinions on trains. So instead of building train tunnels you debate it for 20 years in town halls and NIMBY protests and nothing changes.
This is clearly a hack around that issue. The article mentions a Hyperloop several times, that's the ultimate goal here.
Anecdote, I don't have a lot of mileage (pun unintended), but every girl I've ever dated did not have license, and neither do I, and I am 27. I live alone and bike and bus ride for the most part.
There is the possibility of increased urbanization and improvements to self-driving car technology will make it economically feasible for car ownership to be unnecessary for most, but I highly doubt that happens within the millennial generation. Probably the next one.
But what if the cost were a tenth as much? I posit that for a city of 500,000 - 1,000,000 it might become practical to have subways and that radically changes the transit equation.
So I am very bullish on Musk bringing down the cost of tunneling. It all depends on how low he's able to reduce the cost.
If smart and motivated teams can't do something, can anyone?
With something like soil, maybe they figure the technology will be useful even if it only services projects with easy terrain and environments and avoids areas with swamps.
Actually, the story is that Musk made it up on a whim while stuck in L.A. traffic, founded the company the same day and bought a used drilling rig which started digging in the Tesla parking lot.
Really the main difference is that someone without money and follow through would've just sat in traffic and complained.
Yes, of course, now that he has money, connections, and a powerful reputation, that makes it easier for him to do things. But he created the money, connections, and power by being able to do things even when he had none of them.
And in general - entrepreneur "origin" stories are often bullshit - useful to get go PR, that's it.
You might want to look at them closer. Hyperloop and ET3 are very different from a technical perspective, even though they're superficially similar.
ET3 tubes need 1/1,000,000th of an atmosphere to mitigate the sonic boom, and that makes the pumping requirements exceedingly hard (requiring multi-stage pumping with turbo- and cryo-pumps). That also means ET3 has a higher top speed, assuming you can secure the right-of-way to satisfy the minimum curve radius.
Hyperloop tubes use 1/1,000th of an atmosphere, chosen because it's the lowest pressure achievable with purely mechanical pumping. They then route air around the pod, allowing them to approach the speed of sound despite the fact that air has to speed up as it squeezes around the pod (aka the https://en.wikipedia.org/wiki/Kantrowitz_Limit).
So ET3's pumps see basically the same differential pressure, but 1,000x more volume needs to be pumped per m^3 of air that leaks in. This means the Hyperloop requires less pumping power, fewer pump units, uses only cheap mechanical pumps, and can tolerate more air leakage than ET3. This is a big win, since the tube is the expensive part.
let's judge the outcome - or lack of it - when they fold or succeed.
Cities of 500000 inhabitants which have a subway exist. See
My family is from Lausanne and I spent a few months studying in Rennes–the size and density plus the metro system makes these cities really pleasingly 'human scaled' in my view. Walking-first center city areas with lots of restaurants/shops, easily accessed from less dense areas by metro+good bus systems+intercity train, but small enough overall to not feel sprawling.
The figure is way out. Crossrail in London has a $20 billion total budget (£15b GBP), with 26 miles of tunnel. But the tunnel is only part of the project, several billion is being spent on new regular track and station rebuilds, so the tunneling figure is really closer to $15 billion.
That's about $570 million per mile, but the Crossrail tunnels are just shy of 50% bigger in diameter than what Musk wants to build (20.5' vs 14'). And as the FAQ says, "reducing the diameter in half reduces tunneling costs by 3-4 times".
LA's tunnel might be costing $1B/mile, but how much of that cost is actual construction versus bureaucracy and mismanagement?
The closest thing is the Regional Connector project, which will be 1.9 miles of light rail and has a budget of $1.8B. But that's the entire project budget. Tunneling costs are only part of it; it's hard to find a finely grained budget, but total construction (including four new underground stations) is budgeted at $1.2B here , which is still "just" $600M/mile.
But that project was building a subway including station directly below a riverbed.
A few reasons off the top of my head:
- flexibility; car infrastructure is much more flexible than train infrastructure
- incremental construction - cars already exist, you're only solving the problem of moving them around (building train infrastructure means building more trains with additional train-supporting infrastructure and more railroads outside of tunnels)
- meshes well with electrification of car transportation
- allows to reduce fossil fuel polution with minimum impact on people's habits - instead of asking someone to start using trains, you just ask them to drive into a tunnel, and for the duration of tunnel transit, the pollution (and fuel costs) magically disappear
- related, it's easier do incremental changes than all-out revolutions
- R&D in efficient boring could be of vital importance to future Mars colony
- last but not least, electric PRT system (aka. "packed-switched" public transport) could be, and probably will, incrementally implemented with self-driving electric cars; this again meshes nicely with that future (benefits of PRT over other forms of public transit are a longer topic)
Presumably whether this system is privately or publicly operated, there would be a major toll associated with its use. So the ask isn't just "drive into a tunnel", it's "drive into a tunnel and pay $$$", compared with a new subway line integrated with the existing mass transit system (trains and buses) and under the same fare.
Traffic is often massively asymmetric so you can just reverse the direction it travels at noon.
It seems plausible that keeping a conveyor belt in good service is cheaper than keeping a fleet of railway cars is. It's also significantly less hassle as you don't need to figure out where to put railway cars when they get the end of the track. Finally it's costs would scale fairly linearly with distance, making short belts totally doable in a way that short railway systems are not.
The natural throughput of the system will be high. Like a new car on the belt every x seconds, where x is not a big number, seems totally plausible.
Those aren't new either, but not common for urban transportation.
In Europe, that would be true, but I think in Southern California he can charge exorbitantly per car and people will pay it.
A tunnel for cars is different. Even a single and relatively short tunnel is useful and people would probably pay something for access. This means you would start making money on the investment quite quickly.
I agree that trains are the right thing to do, but that is much larger project and likely too big to be an option for private company.
Now I know why big companies do those reading comprehension tests...
He didn't say that was a benchmark at all. He explicitly said that was one of the highest costs for tunnels.
> with some projects costing as much as $1 billion per mile
I think it's move polivalent to transport vehicles (personal or mpv) that way the last 1-5 miles can be resumed by the vehicle and they don't have to stop everywhere (which is the main crutch of trains), you want to cover as much area and not have "why don't you stop near my house" syndrome.
there's also nothing stopping bicycle riders from using the system provided there are seats to strap into and goggles to wear.
When it's all said and done, Elon is a car salesman and entrepreneur, I guess that's why?
There are obvious benefits of being able to come and go as an individual instead of relying on public transit.
Hygiene, safety, and storage all pop to my mind.
What's the throughput of cars on electric sleds through tunnels?
Just learning how to build tunnels is interesting from that respect.
The reason that isn't stated is because Musk likes to create projects around a "purpose" and business plan for them to succeed (even if they are retro-fitted - that is, he decided first that it would be important to tunnel, and then arrived at the "why tunnels on earth").
edit: not a new thought. some other commenters already pointed this out. I read those after posting this.
Good points. And beyond the technical aspects, there's a lot that the FAQ doesn't say about the service:
- How do you tell your sled where to go? Does it always go to the same place? If so, do you merge lanes? If you merge lanes, wouldn't there be jams there? If instead you build many parallel tunnels, don't you remove the gains you had from building smaller tunnels, by having many more tunnels?
- How is it meant to compete on price or human bandwidth with subways? Surely at 200 km/h you need to maintain space between sleds in case one fails. Plus, the sleds are not large, which limits human bandwidth. Finally, if you have lots of tunnels (at least one for each origin/destination, instead of subways with many stops), you will need to maintain and repair that infrastructure, which will require service tunnels and backup tunnels, which adds to the cost.
Another thought: they don't mention how they'll design the tunnel network yet. My guess is that it will be backboned by double circular tracks (one for clockwise driving, the other for anticlockwise), from which you have regular exit/entrance ramps at each stop. The circularity would avoid having a terminus where everyone slows down.
Still, any design would have a maximum capacity corresponding to how fast vehicles can exit in the worst case, if they all suddenly decided to leave at the exact same stop.
the giant ipad on the dashboard of your tesla, or your phone otherwise.
>If you merge lanes, wouldn't there be jams there? If instead you build many parallel tunnels [etc]
because if the increased speed, one lane is the equivalent of about 2.5 highway lanes in terms of throughput per hour. Regarding safety distance, I think you can actually safely achieve smaller spacing with a roller-coaster style mechanism than with tires on asphalt. I would say that as well is a 2x throughput multiplier. So parallelization seems largely unnecessary.
>How is it meant to compete on price or human bandwidth with subways?
ok so take an 8 car subway train with 40 people per car on a 10 minute interval. 8 * 40 * 6 = 1920 people per hour travel from A to B.
then take sleds each containing a car with 2 people, paced 300ft apart traveling at 125mph. that is 2 people * (125mph / 0.0568182mi) = 4400 people per hour
I think 300 ft is for 75 mph. Using https://en.wikipedia.org/wiki/Braking_distance, the distance at 125 mph is 55 m/s * 55 m/s / (2 * 1 * 10 m/s2) = 150 m = 500 ft, resulting in 2 people * 125 mph / 0.09 mi = 2.8 khumans/h.
(On the demo video, their vehicles look like they are tire-on-asphalt.)
Also, subways have a typical capacity closer to 30 khumans/h in dense urban areas (https://www.thoughtco.com/passenger-capacity-of-transit-2798...).
Also, the concept video shows multi-user pods. If you pack them as full as a rush hour subway, you could probably equal or exceed a subway's throughput.
The express subways are spaced out a little more, closer to 8 or 10 minutes, depending on the line.
here is LA for instance, about 10 minutes average during rush hour https://media.metro.net/documents/5a366ef8-2013-4d21-8e6d-e7...
Melbourne's light rail E-class trams have a carrying capacity of 64 seated: 146 standing. They can regularly mix with pedestrians. The E class is the "big" one at about 40 seconds:
Melbournes older, 6 car trains have a crush capacity of ~1526. Seatwise they have ~500-600, with a standard target capacity of about 800 (above that the extra variance/numbers people start to complain about overcrowding).
Now, those old trains aren't the newest, and they're single-decker and not the biggest or double-decker like sydney's, and they're not the bestest like some of the asian fully-auto metros.
But, my point being is that by the numbers before we start getting too crowded, our quite average older 6 car trains have point in time comfortable capacity about 2-3 times more than your 8 car subway estimate. Hell, three of our light rail vehicles regularly move the numbers of your 8-car subway.
We've not actually accounted for the trips accurately, because if a train runs the full length of its track only carrying its estimated point in time comfortable capacity, the carriages would be quite empty: the total passengers using a train aren't its point-in-time-carrying capacity, but how many get on and off between all the stops along its path. That goes for light rail too. So to find the actual number of people moved by train or light rail, you generally have to multiply the carrying capacity by some additional multiple.
On the other hand, private vehicles generally, in practice have a person per vehicle estimate UNDER 2 (barring geography, time, purpose variances), meaning your estimate is overly optimistic for the cars, and out by about an order of magnitude for the rail vehicles.
I was not being facetious when I made another comment in this thread when I said I was shocked by how inefficient private vehicles were when I actual went down to the intersection and started counting how long it took them to move say 100 people (equivalent of 1 of our trams), nor am I being facetious when I say not only that this is likely a problem with an already known solution, but a problem where The Boring Companies apparent solution is starting with a rough order-of-magnitude efficiency penalty.
I'm honestly a bit...feel like I'm taking crazy pills...that people are talking about the proposal of putting private individual vehicles on rails...in tunnels.
The problem is that most US cities are completely unwalkable, so you need a car once you hop out of the station, or you need an incredibly large subway system.
This is being proposed for LA initially, which is one of the most sprawled, least walkable cities in the US.
I wish we had more walkable cities here.
The tunnels are still pretty big, and the sleds could be 10' wide and 10' vertical if the tunnel ID is 14'. That's pretty comparable to a subway or bus, and the increased distance between the sleds is made up for by the increased speed.
Too much water won't be a problem on Mars... where I think the end-game here is for Musk on why he's learning how to build tunneling machines.
I suspect having mini TBMs which go ahead of the main machine, boring small tubes would be an effective way to give feedback on what's coming up; avoiding nasty surprises / helping to prepare ahead of a change of soil type.
It is well-mapped. LA used to have an oil industry, with oil wells all over the city. So the underground has been explored and studied by the oil industry. UCLA has been studying Los Angeles area geology since the 1920s.
Exploring horizontally has been done for a few projects that lack vertical access. Eurotunnel drilled the service tunnel first. Some mountain tunnel projects in Japan did horizontal test bores. You can't do this directly ahead of the main TBM without interfering with the main dig.
This pre-bore provides three great advantages:
1) Ventilation of the tunnel during the enlargement is greatly simplified
2) You have a very sensible saving on explosives (if explosives are used) or however faster excavating times (because a large part of the amount of explosive is needed to "start" the demolition of the rock, i.e. pull the center "core" out)
3) From the pre-bore you can (when you encounter problematic terrain) drill radial holes for consolidation of the surrounding terrain (though cement injection or other similar techniques)
If the final diameter is TBM excavated as well, #1 advantage above is only partial, #2 is almost non-existing while of course #3 remains, BUT, you cannot make the pre-bore much smaller than the 3/3.6 m diameter as otherwise it would be only useful as a geo prospection mean, as it wouldn't be practical to use it for anything else, and there would surely be issues (for smaller diameters) with ventilation.
AND the other bad news are that - more or less and as a first approximation - a TBM has an operative tunnelling speed of roughly 400 m/month that is almost independent from the diameter (while a traditionally excavated tunnel is more around 100 m/month without pre-bore and 120/130 m/month with the pre-bore), so while it may make sense (of course a lot of factors are involved), if you have a 4 Km tunnel to make a pre-bore that will add roughly 12 month to your 50-60 months project excavation time (traditional), it won't make much sense unless for other very particular considerations to add those same 12 months to the 12 months a full face TBM would take.
What is often done on full face excavated tunnels with TBM is prospection holes (horizontal, drilled from the face of the TBM) in the 30-50 m range, to explore what lies ahead in the immediate future.
Tesla was forced into that technology. The original Roadster had a two-speed transmission and an air-cooled motor. The huge jolt on the transmission when it shifted during acceleration wore it out in months. So Tesla had to develop a motor with a wider power range that would fit in the original space. That forced them to liquid cooling. Previously, liquid cooling an electric motor was considered unnecessary complexity; just make it a little bigger and use air cooling. Now, it's common for electric cars and is being used for electric powered aircraft.
"To solve the problem of soul-destroying traffic, roads must go 3D"
The word "must" is a very strong one here, there are other options:
* Reduce the amount of travel that people need to do (remote work, online shopping).
* Reduce the density of cities (enabled by remote work or longer commutes with better internet access).
* Increase public transport options (higher passenger density).
* Encourage cycling.
I feel like only somebody who lives in LA would make the "must" assertion and not think about all the other options... oh wait:
Yes they would. If you took the existing surface street network and made it 100% buses and/or ground-level trains you could accomodate current subway and road capacity with room to spare, even before you reclaimed all the space currently used for car parking. Private cars are an astonishingly inefficient use of space, and taxis are barely any better.
> The listed alternatives are all nice, but none of them allow you to move at 125+ mph.
We don't need to though. There's no conceivable need for a city to accommodate more people than could live within a 30-minute commute at current speeds if we were willing to build at the high densities that are actually possible.
... and buses are even worse.
NYC works because of trains and as a proponent of train travel and public transportation (except buses) I believe they have indeed solved many problems with their diverse rail network.
Buses are a canard - they are the minimum viable public transport option that were pried out of suburban taxpayer hands and presented to poor urban (usually black) riders by planners who didn't care about public transportation at all.
This ruse has gone on so long that in 2017, well meaning (and brainwashed) proponents of public transportation see buses as one of the core components of a transport network. Wake up. This is false. You need subways and trains.
Well-functioning transit in cities that prioritize it use very few buses and they use them for weird stopgap or edge cases (or emergencies). BRT is a farce. You should be demanding real, not fake, investment in transit networks. You should be demanding trains.
 To be fair, I have seen two very functional BRT models - both in very specific (and wealthy) environments: VelociRFTA in Aspen and Hop/Skip in Boulder. In both cases, however, a well-designed rail corridor would be even better.
London buses have a capacity of 80 to 130 people and are often full. How can that be worse than 60 to 110 cars for each bus?
Even at half the capacity (single deck) you use the space way more efficiently than cars.
Now if you live in a city where the planning was botched, the transit routes made inefficient, and poorly targeted at ghetto areas that's a different problem. In fact you'd probably have the same problem if the same routes were done by trains.
Buses are just a way to transport a lot more people than cars and I can't see how that's a problem...
What's baffling to me is that, in addition to "real" light rail, Seattle is also building out a network of street-level trains. These trains barely carry more passengers than an articulated bus, are subject to the same traffic issues as the buses since they don't have a dedicated right of way, cost way more than adding bus lines, and their tracks create significant hazards for cyclists. I could be wrong, but it seems like this is an example of "buses = bad; trains = good" thinking gone awry.
Doesn't this just mean that they are expensive? I heard complaints about how expensive Tokyo's subway is. Reducing price and propping the system with tax can be a better approach in the long term, because that can encourage more people to use public transit and reduce demand for costly highways.
(Also, one could argue that the freedom to move around at an affordable price is a basic service the government should strive to provide, although I'm sure some people will regard such an idea as socialist nonsense.)
You could argue, perhaps, that the price is expensive relative to what Japanese people earn, but from my impression it was a very effective and reasonably priced public transportation system.
But the MTR actually was subsidized by the government, which let MTR Corporation develop the land above the subway to make malls and stuff, which they make even more money on. Presumably some of this profit gets reinvested into the system itself.
Beyond the price, Tokyo Metro is almost always on time and pretty clean, and generally the delays happen late at night (the delays are only for a minute or two). Having been here for over a month, I've only experienced one daytime delay that lasted more than 30 seconds.
you don't really want more people in Tokyo metro, at least not in peak hours
Since employers always pay for commuting costs a regular working person spends very little on train tickets day to day. Me and my wife spend about $100 per month between us. With our companies paying a further $70 per month for each of us for our passes to work.
Dirt roads are extremely cheap and have been around forever. That doesn't make them the best choice in a modern society.
A cable tramway is one option for an aerial system. The load-bearing capacity of a 15mm steel cable is impressively high, and it can be strung along pylons.
Not that you'd want to bolt street cars to such a system, but it's an example of a possible people-mover that doesn't require persuading a multiple-kilometers-long bolus of solid granite it'd prefer being elsewhere.
Whilst I'm aware that Musk's premise here is that he can be the boringest guy ever, I'll note that the Gotthard Base Tunnel, in Switzerland, required 17 years of excavation to extend 35.5 km.
Tunnel systems can also give rise to some interesting cascade failure modes. Cab-forward deisel locomotives aren't generally considered a risk factor, until they are. Summary of an accident report, here, five souls lost to bad design of stock and tunnel, inadequate maintenance, poor judgement, and panic response:
Also people have to accept having a highway right next to their window: https://thumb1.shutterstock.com/display_pic_with_logo/141562...
The newer the subway lines in Tokyo are fun because they have to built in under the others (as referenced in the FAQ), you can tell you're on a new line when you descend down flights and flights of stairs.
I have ridden on the Nozomi and it's a fantastically smooth ride. There are indicators of the current speed on the wagon passage doors and it is incredible when it achieves 270+ km/h and everything is passing by so quickly, and yet you can drink your beverage from a cup just fine, just like in an airplane :)
Add a congestion charge or tolls, and a proper public transport network. The solution is not more roads, it's fewer cars.
You can't clean a hotel or flip a burger remote.
Public transit has failed to solve the problem despite a 100-year head start.
Cycling... in LA...
I don't think the Boring Company is trying to solve the gridlock. They will, however, provide an option for those who can afford to pop down into a Teslalane [sic] for a trip to the airport. And that's fine. It's [Teslalanes] infrastructure that ultimately helps the city thrive until the time that the land use patterns rebalance. There will always be traffic - but it won't always have the same overall impact.
I take objection to this because, aside from other cities where public transit is the norm, the interurban system in LA  was dismantled, partially because it was forced out by cars that increased congestion to the point that streetcars could no longer run on time, and partially because of car companies advocating that buses could replace the streetcars (they didn't).
Things don't exist in a vacuum, and LA decided to make itself a city where you could only be comfortable getting from place to place inside a car.
Public transit SOLVED the problem 100 years ago in the US. And then it was sabotaged by the big automakers.
I think American Individualism sabotaged Public Transit when it realized it could avoid the public by using automobiles.
So the question here really is "which would improve LA more: tunnels that carry trains, or tunnels that carry carts that hold single cars?"
There is plenty of strong evidence that shows adding additional road capacity increases overall traffic. I'm not sure that adding ways to move cars around faster wouldn't have the same impact, versus a train.
If the boring company solves issues with personal travel then cities like LS will become less dense. There's a reason urban sprawl didn't exist before the car.
Nope. Denser cities are both more efficient and more walkable.
The worst part is that this had been foreseen and warnings have been made but nothing is done to deal with it.
I live in San Francisco and I assert that: To solve the soul-destroying practice of driving from (north of golden gate bridge) to SFO, roads must go 3D (tunnel).
You may not be aware of this, but if you need to go to SFO from Marin (or anywhere north of the city) you need to drive through small residential neighborhoods, stopping at up to 12 stoplights. It's incredibly wasteful of time and gas and degrades the lives of everyone involved. You find yourself stopped in traffic on a four lane boulevard in front of a single family home with a yard. That's how you get to SFO.
San Francisco desperately needs a tunnel from the GGB to SFSU/ParkMerced.
Additionally, public transport often interferes with regular road traffic, making the problem worse. The solution is to use an elevated train (Chicago) or subways. So now you're back at 3D.
And biking in a low-density city isn't a practical solution.
How do the sleds preclude developing public transport? Why wouldn't we see mini-vans pick people up from homes or community hubs and then use the tunnels to take an express route to the CBD? Or larger sleds that accommodate a bus or truck sized pod? If these HOV pods avoided a congestion charge, there would be an incentive to use them.
Obviously drivers and their cars will fill any space given to them, and cycling tunnels might be too expensive, but hopefully a change in traffic flow and parking availability would make room and safety for cycling above ground.
Imagine buses with good cycling storage so you could ride to the hub, board a bus, zip to the CBD, alight and ride the last few kilometres to your destination.
Entrenched interests will fight it for a time, but it wouldn't surprise me if these guys could make it happen.
Intersections can only be solved with 3d roads, by eliminating overlaps. The bigger the city, the more artery roads you need with uninterrupted flow, and they eventually choke each other. Build tunnels and you can have point-to-point connections without choking off local flow.
Reducing the number of drivers can't fully solve gridlock because at some point you have to hit a long light when you try to move from a high flow to low flow area. The only way to avoid that is with onramps and elevated freeways, but you can't build enough of those.
Every point you brought forward is also true for subways, but it's again at least an order of magnitude more space-efficient than sending cars through tunnels.
And also a huge waste of energy on an ongoing basis. An aircraft has to continuously expend energy on fighting the gravity.
> the problem with digging is that many people live and work and drive right above where you dig.
The FAQ addresses that by noting that below ~2 tunnels height, people wouldn't even notice.
Easier, yes. Cheaper, no.
> At some point the holes could cause collapses.
The risk is extremely low, and car accidents have caused a vastly greater number of deaths than any other form of transportation.
> There's also water mains and other hazards and obstacles.
Pretty sure there were some pretty massive hazards with flying too.
> Sounds dangerous.
Which a lot of people said about flying as well. And it's vastly safer than a car.