But all this discussion of what to put in the tunnel seems very silly to me. Are they just re-discovering subways? Do they know that there are subways in the world (e.g. Paris) that run out rubber tires?
For example, expanding subway systems is currently in the hands of very badly run semi government institutions who are arguably quite bad at even utilizing the tunnels they have. E.g. the new york subway system is famously less efficient than ever due to the fact that they keep reducing the speed at which trains travel through it. Digging new tunnels is relatively rare for them; and when they do dig new tunnels, they tend to just use them exactly the same way as their existing tunnels, which is not very efficiently. Also, like most government infrastructure projects, progress is slow and things tend to go way over budget.
Musk's approach is twofold: 1) turn tunnel digging into a scaleable business. 2) provide concrete things to do with these tunnels that are not backwards and stupid that he can sell. For example, if you have autonomous vehicles, you don't need a lot of expensive infrastructure inside the tunnels to get from A to B. Infrastructure like rails, signaling equipment, power lines for the trains, etc. It so happens he has a business for autonomous vehicles already. He sells the whole package. That's why he's emphasizing the use cases.
This is classic Musk, he thinks end to end an he might actually pull it off.
Things always are wonderful when they're research projects that don't need to conform to real-world limitations.
My point here is that there's still a lot of room for improvement, even if you limit yourself to trains. It doesn't seem like such a stretch to extend it a bit further to this new emerging system.
His first argument is that it's currently too expensive to have any innovation. This tunnel cost 10 millions $. Sure it's usage is still hypothetical, but you can't say this won't be much more accessible to innovate.
I'm in Montreal, our subway barely changed in the past 30 years. I was lucky, I was affected by one of the only change they did in theses 30 years, 3 more stations on an already completely full line. That came with a 745m$ price for 3 stations that sure allowed people further to take it, but it didn't increase at all the actual capacity. It's hard for any of our administration to even consider any major expansion because of that.
If making smaller projects now make sense, maybe we will see more innovation in the technology, in how they are handled, etc...
Montreal's metro throughput is not gated by the tunnel capacity. It is gated by the amount of trains in operation. Adding additional cars on the 'already full line' would increase the line's capacity. Neither the orange nor the green line are close to full.
The issue with the orange line extension isn't that the lines are full. It's that 1) subway costs are heavily subsidized at the municipal and provicial level, 2) they were extended to Laval which funds the STL, not the STM, and 3) there was no revenue or cost sharing agreement between Laval and Montreal to subsidize the STM in proportion to the burden placed on the STM by Laval riders.
This issue with cross-subsidization also lies at the core of the municipal agglomeration which occurred in Quebec metropolitan regions.
Montreal won't consider additional subway expansion not because of financial and infrastructure cost reasons, but because of political ones, much in the same way that internal negotiations regarding the dual super-hospital projects were intentionally sabotaged for political reasons.
China is indeed digging at huge speed.
My understanding with the Boring company is not that they are doing anything particularly special but merely doing things in a way that facilitates economies of scale. So, they standardize designs, equipment, logistics, etc. and they use automation. If you do a one off tunnel with a machine that will only be used for that tunnel, that doesn't make sense. If you are planning to do many tunnels that makes a lot of sense.
2 lanes of 3 rails that are grade leveled should be relatively less expensive than paved, with rebar grade leveled; especially over time, with the increased wear that liquid has.
Also note that if you get an increased amount of people commuting in these tunnels without their own cars, new public transportation built by the city becomes a lot more valuable as well, since there's already a lot of people getting around without cars.
That said it is funny how private companies seem to rediscover public transport. Looking forward to Uber Train.