Now Boring Tunnels belong here because they requires EVs and they could be an incredible enabler of EVS. Can't practically have a tail pipe in the tunnels even as some underwater tunnels have enabled that you'll notice their astronomical cost- and of course tail pipes in tunnels have added to the cost of construction- so green tunnels are cheaper on that front too. Of course the people at Boring have thought of these things but maybe others have something they haven't. I haven't seen what follows mentioned in the press, but I've seen a lot of concern about accidents and failures and bottle-necking from edge cases in comments. 1. Presumably the Tesla system and that of other cars would pre certify use of the tunnel before entrance by a diagnostics check. And presumably this actually adds merit to a vertical drop elevator at both entrance and exit as a way to make sure that no cars get in that don't pass and yet getting rid of such elevators any way possible could reduce cost further and increase reliability. Is the Tesla system like a magna steer system(?) you really would want to disable any mechanical linkage while in the tunnel under AP unless you could be sure the coasters could overcome inadvertent or even misguided intentional steering input. 2. It seems the best and most reliable situation for coasters would be for the coasters to generally not make contacts and rely on the autopilot to guide at tight tolerance. This of course could create a stability situation if they did make contact. I wonder proper channeling of air by coaster fairings or air guides could create the air hockey effect and help prevent contact and help slot the vehicle at speed- the issue is probably more at speed so aero dynamic guides might help. 3. When there is a flat or failure (much less likely in an EV) I could see compact units running between the rails that seem to be in the tunnels running under the cars coming to jack up the car and take them to an elevator. This has the advantage of being able to run under traffic but when it gets to an elevator there will need to be a mechanism to push a car onto the elevator if need be and one to push it off the elevator into an emergency space or even spaces to free up the elevator again for both input and output. Also it would seem necessary to have the pedestrian cars and or special forklift cars that could fork lift front and back other vehicles at times. Also may be necessary to have regular pit stop pull offs if necessary for logistics but these types of arrangements may present some risks in they are breaks in the continuity of the channel? Because of the need to think through the logistics (which be improved as need be even after the system is put in place) it almost seems like it has the issues of launching bullets through long barrels. Gatling gun type dynamics. So many offshoots and axis points to attend to logistics in real time seem needed and this pushes cost but the pay off is huge. Fool think is always trying to drive growth but they need to understand that ain't happening if traffic is a choke point. Bezo's idea for the doing all manufacturing on the moon and taking the logistical traffic vertical would help quite a bit but they have to understand that their fool growth for the sake of growth (bs that supports money for the sake of money unfortunately- but getting these fools in line can be helpful) is infeasible unless you go vertical above and below ground with tunnels and drones and autonomous vehicles- even eliminating stop lights and with drones and with a green revolution. This is not a maybe this is a necessity even against issues like urban sprawl their little cities must flow with the techniques applied to CPU design and at some point soon with a quantum computer factoring the Hamiltonians in real time an freight flow into a city and optimum placement of freight units within where house stacks arriving at some sort of macro super fluidity for all things that travel. This is not a maybe this is a necessity unless they want to be road kill for new green economies like China that are not built out and won't do this. Don't do it then have fun learning Mandarin in middle age. *Finally wonder if magnet spacers might work but be cost prohibitive even if the magnets built into the side walls were far apart. Any of this would add cost and rare earth could be cost prohibitive and un-powered magnets could run down with time- thinking maybe combo of coaster aero fairings and cheaper non rare earth magnets could be circuited together in a manner such that the vehicle at speed built a field just ahead of the vehicle that would form a strong positioning/tracking force. I wonder about the slotting or vertical tracking of such fields as the friction of actual coasters might be superior. A big downside to such a system is that it presumably adds cost and fail points to the tunnel that coasters don't as you move in the direction of mag lev. But coasters create wear and tear as well and reliability issues. If vertical movement is a concern with the regard to such coasters maybe a generally passive tail hook relative to the lower rails- probably not.
The logistics of using small tunnels to move cars long distances underground, with single-car elevators for entrance and exit, would only work if the system was restricted to "VIPs only". Those small elevators would be choke-points which would drastically limit the throughput of the system. I understand why Elon Musk is jonesing for a faster way to commute to work and back home, but this kind of system would only work if it was restricted to Elon and a few of his friends. With only a small number able to use the system, the use fees would have to be be very, very high to pay for building and maintaining the system. If you scale this idea up to larger tunnels running vehicles which can carry a large number of passengers at once... well, we already have that sort of system. It's called a "subway". No elevators required except to handle handicapped passengers. Elon has a vision of reducing the cost of digging tunnels by an order of magnitude (that is, to 10% of the current cost). That would make subway systems much easier to pay for and to run, but it still would not make Elon's fantasy of a system of traffic tunnels restricted to use only by super-rich VIPs any more practical. For more on the subject of why VIP-only transportation systems will never be economically practical (at least, not affordable beyond some very limited privately owned areas like Disney World), see: Human Transit.org (blog): "The Dangers of Elite Projection"
If he can get the cost to 1/100 or 1/1000 then it works. And claims to have done a mile for 10 million or 4 million or some such number already where the comparison is 1 billion a mile or something like that. But I agree that the ingress egress to the tunnels has to have a way that doesn't involve a lot of easements and I am guessing that parking structures could be converted to become on and off ramps in a multiplexer fashion.
Having lived in the Washington DC area, I have memories of: I've seen sketches that have a side-rail at each station so the main track remains free for cross town cars. Of course a proper automobile tunnel has a sloping entrance and exit: I could envision a system that has sets of rail-cars that can leave to a side rail while the rest of the cars proceed to the next stations. In effect, 3-4 different color coded, smaller cars, that pull off into a station where passengers can get on the rail-car going to their next destination. Then as gaps in the existing stream of rail-cars are dynamically scheduled, the individual cars accelerate to join the stream. In the mix would be cargo and car transport platforms. I think the elevators are to avoid the very high cost of surface real estate. Perhaps the first tunnels are from edge-to-edge of town freeways that don't discharge in the center. So in effect these become new freeways with longer runs than the current ones so frequently jammed up. Going from San Francisco to San Diego, the tunnel by-passes Los Angeles. These tunnels also become the natural route for 'hyper loops.' The evacuated tunnels would require cars built to aircraft standards traveling at hundreds of miles per hour. Bob Wilson
Have you watched the original Boring Co. concept video? It shows an entire lane of parallel parking in a downtown area converted to these single-car elevators. (And no safety fences or rails to prevent anyone from driving/walking into a hole, but that's a rather trivial objection compared to the much more serious practical and economic problems with the concept.) The picture below isn't from the original video, but shows the same idea of replacing downtown parking places with these elevators: Hard to imagine a higher real estate cost per square foot than that! And imagine if such a system actually was built and did carry a significant amount of traffic. Imagine how much worse the congestion would be in such downtown areas if you could drive there in your car quickly and easily! Relieving downtown traffic congestion in dense urban areas is done by getting people to use mass transit in such areas rather than individual cars. Not by making it a lot easier to reach such areas in their car! From start to finish, it seems that the Boring Co. concept has not been thought through. It continues to amaze me that Elon can get people to take the idea seriously. It seems to me like a combination of an ultra-rich man's fantasy and a grand practical joke which Elon has foisted off on the public. Like the idea of replacing gasmobiles with fool cell cars, the closer you examine this scheme, the less sense it makes.
I'm fairly sanguine about the 'access' problem. Elon has a good engineering habit of working the hardest part of a problem first ... the tunnel. Then working the next, and next, and next. For example, there is no 'model year' for a Tesla but a version number that changes as newer and better engineering solutions occur. One thing for sure, I don't see any ICE or plug-in ICE car getting access. The fire, toxic gas, and heat are more than the tunnels should have to deal with. Given less than 1-2% of the the vehicles are pure EVs, there will be a natural selection for more EV adoption. Consider it to be the ultimate HOV pass. Bob Wilson
What makes the most sense to me (in a gut sense, I make no claim to be an expert) is to move industrial products on the surface by rail and truck, commercial goods in urban environments underground by a network of tunnels/elevators, small BEV vans, and some drones, and people on the surface and in the air via a combination of automated busses, cars (Waymo/Lyft), motorcycles/tuk tuks, and short hop drone coptor flights. If all surface transportation is automated, traffic jams and gridlocks all but disapear. Self-driving vehicles can be programmed to emulate traffic patterns that benefit the greater good (for a preview of what this would look like, study traffic patterns in southeast asian countries...at first it looks like chaos, but after driving in it for a while you realize that it is far more courteous and fluid than the western style stop and go/road rage/get-out-of-my-way style of traffic). All urban surface transportation can be BEVs with super capacitors to help with range (busses in Paris are already testing this out). Automated drone coptors take care of the VIP transport. Cargo containers are already very efficient, so no need to reinvent the wheel there, just create an automated underground rail/truck system that can move containers as-is, instead of having to repack them into semi-truck trailers. Distribution centers will continue to be important, and will become more and more automated. Retail shops will just become a tangible face of online shopping, so in many cases the delivery of goods will happen from factory direct to consumer through a combination of the above-mentioned methods. The ability to exhaust fumes from a tunnel is really not that difficult, just requires some ventilation fans, many long tunnels already do this. BEVs and other means of electric transport underground are better in the long run, but in the short run putting ICEers underground would at least give us more of an ability to filter the emissions and sequester them in the soil.
Well, you yourself pointed out the solution to that problem: "Of course a proper automobile tunnel has a sloping entrance and exit:" Such entrances should lead to underground holding lots where cars could queue up to enter the tunnel system, if such a thing were ever built. But the most fundamental problem here is that there is no way the usage fees could ever repay or justify the cost of construction, as explained in some detail, with real-world examples, in the article I linked to above: "The Dangers of Elite Projection".
