Only electric and autonomous cars will be able to use the tunnel system designed by Elon Musk. Credit: The Boring Company
Isabel Rubio Arroyo
In 1982, Ridley Scott set the action of Blade Runner in a futuristic version of Los Angeles, in which flying cars zip through the air in the year 2019. Having now reached that date, and with the opposite idea in mind, the mogul Elon Musk has gone one step further in his dream to revolutionise the world of transport. First, he founded Tesla to kick-start the production of the electric car, then he announced the Hyperloop—a high-speed transport system for passengers and goods that works with vacuum tubes—and now he aims to end traffic jams within major cities. To this end, he wants to build a system of underground tunnels for cars to drive at 240 kilometres per hour, twice the maximum speed allowed on our highways. Could Musk's plan actually come true or is it just another science fiction idea?
Although at first glance it might seem like a utopia, the founder and CEO of Tesla has already unveiled in Los Angeles (California) a prototype underground tunnel four metres in diameter and almost two kilometres long. To access this kind of subsurface highway, the driver descends with their vehicle by elevator. Then the car is fitted with special wheels that adapt it to the rails of the tunnel and prevent it from impacting with the walls when driving.
"The proposal of this tunnel seems too futuristic," says Juan Santamera, the president of the Spanish Civil Engineers College, emphasising that "certain speeds have not yet been achieved or exceeded." Although Musk’s stated intention is that vehicles will move at 240 kilometres per hour, in the test he did with some journalists in December 2018 when he presented the prototype, the car did not exceed 70 kilometres per hour.
Santamera explains that, technically, it would be possible to build this tunnel system, but he doesn’t believe it’s a solution to end traffic jams: "Only to move them from one point to another." In addition, "the cost would be huge and the benefits that would be obtained would not justify that investment."
After founding Tesla to promote the electric car, Musk intends to end traffic jams in large cities. Credit: prayitnophotography
The secret: low cost drilling
Even so, Musk argues that the cost to build these tunnels would be enormously reduced compared to those used by trains and subways. Behind the project is The Boring Company, a firm owned by Musk that has invested 10 million dollars in excavating the prototype tunnel. The costs would decrease by tripling the speed of drilling and designing the tunnels with a smaller diameter, as explained on the company's website, which aims to "reduce costs by a factor of ten, from 600 to 60 million dollars per kilometre."
However, public transport analysts such as Alon Levy criticise "Musk's lack of knowledge about the factors that affect tunnelling costs." Levy claims that the drilling speed and diameter of the tunnel don’t influence the price per kilometre of the project very much, and adds that those costs promised by Musk have already been achieved before, for example in construction works such as the expansion of the Madrid Metro between 1995 and 2003. The public transport policy consultant Jarrett Walker also entered into a direct controversy with Musk months ago, when labelling his idea elitist.
Only electric and self-driving cars will be able to access this system of tunnels. The special wheels they need would cost between $200 and $300, according to Musk. Today around 10% of new cars in California are electric, a number expected to exceed 50% by 2024, according to Miquel Testar, a telecommunications engineer who leads technology projects in Silicon Valley for the automotive sector. With regard to driverless vehicles, "the introduction level is lower, but an exponential penetration is expected starting from 2025."
Musk has pledged that these tunnels would also have vehicles reserved for transporting pedestrians and cyclists, who will be given priority. A trip on this type of public transport could cost around a dollar, according to the founder of Tesla. Santamera reflects on the difference of this system with the subway: "It seems like a rediscovery of the train. How many passengers would be transported each day? Because the subway transports thousands of passengers."
Many details to be worked out
There are still many aspects of the idea that the entrepreneur has not explained. For example, how the vehicles will be incorporated back into the main traffic flow or how an accident or breakdown in the tunnel will be handled. "If I have an accident in a single-lane tunnel or I get a flat tire, what do I do?" asks Irene Chico, architect of the Lledó group. Such a small diameter can make it difficult to rescue people or evacuate the tunnel.
This is not the only aspect that the South African-born tycoon has to take into account. To ensure the ventilation of the tunnels and allow the carbon dioxide that is emitted when breathing to escape, Santamera explains that the underground system must have vents. "In addition, cars tunnels can’t be very long because a claustrophobic phenomenon can occur. There have been cases of people becoming mentally blocked at the wheel," says the engineer.
The company has already encountered some setbacks in carrying out its project in Los Angeles. In November, it abandoned its plans to develop another tunnel in the city after facing lawsuits from various neighbours for allegedly violating state environmental protection laws, according to TechCrunch.
Ideas for a new generation subway
This system of tunnels also has its positive side. "Although Musk's approach seems to be aimed at private transportation in automobiles, its exhibition does have certain aspects of possible medium-term application to the public transportation system of a large city," says Felipe Mendaña Saavedra, a road engineer with almost forty years of experience in underground construction projects. This system would allow the size of the subway tunnel to be reduced because "for a vehicle with an electric motor, it isn’t necessary to install the power supply by catenary." Also, a "smoother rolling of the new subway vehicles" could be achieved as a result of the modification of the steel wheels and the current heavy tracks, and the size of the stations could possibly be reduced.
The elevators to descend to the tunnel, which would be accessed from the same street, would only occupy two parking spaces. Musk argues that stations could be built throughout the city without changing the character of Los Angeles. For the architect Irene Chico, this project "is a way to gain space for the citizen." "If we assume that the high speed roads are underground, the surface roads would be narrower, there would be more public spaces and the pedestrian and bicycle would have more prominence," she says. Chico argues that it would be essential to undertake a very detailed urban study with a future projection that takes into account where the city is going to grow and how transport will evolve. For the moment, she believes that although the project is "a bit utopian," it invites us to value the pros and cons and to "ask ourselves questions that are difficult to answer: Will we still have cars in 30 years? Will they circulate in the same way? In what way will we care about the environment?"
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