Chris Anderson: Elon, hey, welcome back to TED. It’s great to have you here.
Elon Musk: Thanks for having me.
Chris Anderson: So, in the next half hour or so, we’re going to spend some time exploring your vision for what an exciting future might look like, which I guess makes the first question a little ironic: Why are you boring?
Elon Musk: Yeah I ask myself that frequently. We’re trying to dig a hole under LA, and this is to create the beginning of what will hopefully be a 3D network of tunnels to alleviate congestion. So right now, one of the most soul-destroying things is traffic. It affects people in every part of the world. It takes away so much of your life. It’s horrible. It’s particularly horrible in LA.
Chris Anderson: I think you’ve brought with you the first visualization that’s been shown of this. Can I show this?
Elon Musk: Yeah, absolutely So this is the first time — Just to show what we’re talking about. So a couple of key things that are important in having a 3D tunnel network. First of all, you have to be able to integrate the entrance and exit of the tunnel seamlessly into the fabric of the city. So by having an elevator, sort of a car skate, that’s on an elevator, you can integrate the entrance and exits to the tunnel network just by using two parking spaces. And then the car gets on a skate. There’s no speed limit here, so we’re designing this to be able to operate at 200 kilometers an hour.
Chris Anderson: How much?
Elon Musk: 200 kilometers an hour, or about 130 miles per hour. So you should be able to get from, say, Westwood to LAX in six minutes — five, six minutes.
Chris Anderson: So possibly, initially done, it’s like on a sort of toll road-type basis.
Elon Musk: Yeah.
Chris Anderson: Which, I guess, alleviates some traffic from the surface streets as well.
Elon Musk: So, I don’t know if people noticed it in the video, but there’s no real limit to how many levels of tunnel you can have. You can go much further deep than you can go up. The deepest mines are much deeper than the tallest buildings are tall, so you can alleviate any arbitrary level of urban congestion with a 3D tunnel network. This is a very important point.
So a key rebuttal to the tunnels is that if you add one layer of tunnels, then that will simply alleviate congestion, it will get used up, and then you’ll be back where you started, back with congestion. But you can go to any arbitrary number of tunnels, any number of levels.
Chris Anderson: But people — seen traditionally, it’s incredibly expensive to dig, and that would block this idea.
Elon Musk: Yeah. Well, they’re right. To give you an example, the LA subway extension, which is — I think it’s a two-and-a-half mile extension that was just completed for two billion dollars. So it’s roughly a billion dollars a mile to do the subway extension in LA. And this is not the highest utility subway in the world. So yeah, it’s quite difficult to dig tunnels normally. I think we need to have at least a tenfold improvement in the cost per mile of tunneling.
Chris Anderson: And how could you achieve that?
Elon Musk: Actually, if you just do two things, you can get to approximately an order of magnitude improvement, and I think you can go beyond that. So the first thing to do is to cut the tunnel diameter by a factor of two or more. So a single road lane tunnel according to regulations has to be 26 feet, maybe 28 feet in diameter to allow for crashes and emergency vehicles and sufficient ventilation for combustion engine cars. But if you shrink that diameter to what we’re attempting, which is 12 feet, which is plenty to get an electric skate through, you drop the diameter by a factor of two and the cross-sectional area by a factor of four, and the tunneling cost scales with the cross-sectional area. So that’s roughly a half-order of magnitude improvement right there.
Then tunneling machines currently tunnel for half the time, then they stop, and then the rest of the time is putting in reinforcements for the tunnel wall. So if you design the machine instead to do continuous tunneling and reinforcing, that will give you a factor of two improvement. Combine that and that’s a factor of eight. Also these machines are far from being at their power or thermal limits, so you can jack up the power to the machine substantially. I think you can get at least a factor of two, maybe a factor of four or five improvement on top of that.
So I think there’s a fairly straightforward series of steps to get somewhere in excess of an order of magnitude improvement in the cost per mile, and our target actually is — we’ve got a pet snail called Gary, this is from Gary the snail from “South Park,” I mean, sorry, “SpongeBob SquarePants”. So Gary is capable of — currently he’s capable of going 14 times faster than a tunnel-boring machine.
Chris Anderson: You want to beat Gary.
Elon Musk: We want to beat Gary. He’s not a patient little fellow, and that will be victory. Victory is beating the snail.
Chris Anderson: But a lot of people imagining, dreaming about future cities, they imagine that actually the solution is flying cars, drones, etc. You go aboveground. Why isn’t that a better solution? You save all that tunneling cost.
Elon Musk: Right. I’m in favor of flying things Obviously, I do rockets, so I like things that fly. This is not some inherent bias against flying things, but there is a challenge with flying cars in that they’ll be quite noisy, the wind force generated will be very high. Let’s just say that if something’s flying over your head, a whole bunch of flying cars going all over the place, that is not an anxiety-reducing situation. You don’t think to yourself, “Well, I feel better about today”. You’re thinking, “Did they service their hubcap, or is it going to come off and guillotine me?” Things like that.
Chris Anderson: So you’ve got this vision of future cities with these rich, 3D networks of tunnels underneath. Is there a tie-in here with Hyperloop? Could you apply these tunnels to use for this Hyperloop idea you released a few years ago?
Elon Musk: Yeah, so we’ve been sort of puttering around with the Hyperloop stuff for a while. We built a Hyperloop test track adjacent to SpaceX, just for a student competition, to encourage innovative ideas in transport. And it actually ends up being the biggest vacuum chamber in the world after the Large Hadron Collider, by volume. So it was quite fun to do that, but it was kind of a hobby thing, and then we think we might — so we’ve built a little pusher car to push the student pods, but we’re going to try seeing how fast we can make the pusher go if it’s not pushing something. So we’re cautiously optimistic. we’ll be able to be faster than the world’s fastest bullet train even in a 8-mile stretch.
Chris Anderson: Whoa, Good brakes.
Elon Musk: Yeah, I mean, it’s — yeah It’s either going to smash into tiny pieces or go quite fast.
Chris Anderson: But you can picture, then, a Hyperloop in a tunnel running quite long distances.
Elon Musk: Exactly, and looking at tunneling technology, it turns out that in order to make a tunnel, you have to — In order to seal against the water table, you’ve got to typically design a tunnel wall to be good to about five or six atmospheres. So to go to vacuum is only one atmosphere, or near-vacuum. So actually, it sort of turns out that automatically, if you build a tunnel that is good enough to resist the water table, it is automatically capable of holding vacuum.
Chris Anderson: Huh
Elon Musk: So, yeah
Chris Anderson: And so you could actually picture, what kind of length tunnel is in Elon’s future to running Hyperloop?
Elon Musk: I think there’s no real length limit. You could dig as much as you want. I think if you were to do something like a DC-to-New York Hyperloop, I think you’d probably want to go underground the entire way because it’s a high-density area. You’re going under a lot of buildings and houses, and if you go deep enough, you cannot detect the tunnel.
Sometimes people think, well, it’s going to be pretty annoying to have a tunnel dug under my house. Like, if that tunnel is dug more than about three or four tunnel diameters beneath your house, you will not be able to detect it being dug at all. In fact, if you’re able to detect the tunnel being dug, whatever device you are using, you can get a lot of money for that device from the Israeli military, who is trying to detect tunnels from Hamas, and from the US Customs and Border patrol that try and detect drug tunnels. So the reality is that earth is incredibly good at absorbing vibrations, and once the tunnel depth is below a certain level, it is undetectable. Maybe if you have a very sensitive seismic instrument, you might be able to detect it.
Chris Anderson: So you’ve started a new company to do this called The Boring Company. Very nice. Very funny.
Elon Musk: What’s funny about that?
Chris Anderson: How much of your time is this?
Elon Musk: It’s maybe two or three percent.
Chris Anderson: You’ve bought a hobby. This is what an Elon Musk hobby looks like.
Elon Musk: I mean, it really is, like — This is basically interns and people doing it part time. We bought some second-hand machinery. It’s kind of puttering along, but it’s making good progress, so —
Chris Anderson: So an even bigger part of your time is being spent on electrifying cars and transport through Tesla Is one of the motivations for the tunneling project the realization that actually, in a world where cars are electric and where they’re self-driving, there may end up being more cars on the roads on any given hour than there are now?
Elon Musk: Yeah, exactly. A lot of people think that when you make cars autonomous, they’ll be able to go faster and that will alleviate congestion. And to some degree that will be true, but once you have shared autonomy where it’s much cheaper to go by car and you can go point to point, the affordability of going in a car will be better than that of a bus. Like, it will cost less than a bus ticket. So the amount of driving that will occur will be much greater with shared autonomy, and actually traffic will get far worse.
Chris Anderson: You started Tesla with the goal of persuading the world that electrification was the future of cars, and a few years ago, people were laughing at you. Now, not so much.