Commentary: An engineer’s thoughts on Elon Musk’s vision of underground roads

Elon Musk announced a futuristic vision of transportation involving underground roadway systems beneath bustling cities such as Los Angeles. The venture that will make it all happen, called The Boring Company, will rely on a vast network of tunnels and has been dubbed “amazing and impossible” by commentators.

A brief concept video posted to YouTube shows a flash red Tesla vehicle amidst gridlocked traffic. The “game changer” appears in the form of a futuristic metal elevator that lowers the Tesla underground to a road network in which individual cars are transported at high speeds on metal trolley-like platforms between destinations — doing away with traffic and associated collisions.

“As with most radical innovations today, science fact was once science fiction. If we’re going to help design the future of transport, we have to be able to envision it,” said Aurecon’s Chief Innovation Officer John McGuire.

Global engineering and infrastructure advisory company Aurecon is currently working on a multitude of city-shaping tunnel projects that will see communities transformed as the firm helps enhance their connectivity and livability. These projects include Melbourne’s Metro Tunnel project featuring two 9-km tunnels and five new stations added to the city’s underground rail network; Sydney’s WestConnex New M5 with 9-km-long twin tunnels from Kingsgrove to a new interchange at St Peters; and Auckland City Rail Link, a 3.4-km underground rail line consisting of twin driven tunnels.

In the following commentary, Aurecon Tunneling Expert Tom Ireland weighs in on whether Elon’s vision really is as impossible as it sounds.

Overcoming mobility challenges

Many of the world’s largest cities have reached their capacity to absorb new infrastructure “on the ground.” These cities are looking at solutions — both above and below the ground — to overcome mobility challenges.

Navigating through long-established built form can be technically and aesthetically challenging, so creating below-the-ground transport networks such as underground rail and road tunnels is high on many cities’ agendas, and these projects are currently transforming cities around the world.

Musk’s futuristic tunnel system is ambitious and innovative. Going underground makes sense and many cities have vast tunnel networks beneath heavily populated areas, for example, the London Underground — so we know it can work. His vision presents an exciting alternative to our gridlocked present.

Solving the cost conundrum

A project of this scale would transform the face of transport as we currently know it. A major barrier will be cost. However, we live in a complex transport environment where multi-modal solutions must be on the table and, for some of the world’s largest cities, this solution could be an attractive option.

Historically, there are three elements that make up the cost of tunnel boring: equipment, materials, and labor — each making up roughly a third of the cost. If we see significant enough advances in tunnel boring and new materials (perhaps at the heart of Musk’s invention), cost will likely decrease sharply and make Musk’s futuristic tunnel system more achievable. This will involve a move away from concrete toward a higher-strength, lighter-weight material for lining tunnels and may even encompass 3D printing this lining as part of the tunnel excavation cycle.

In terms of underground trains, it’s the stations that represent the most significant network cost. Related to accessing the type of tunnels Musk suggests, we’ll need to ensure the mechanization of the lifts that transport cars underground is cost-effective and quick.

Rethinking traditional design

Traditionally, tunnels are designed to integrate a large amount of safety equipment. Musk’s proposal, in which cars are propelled forward by electric trolleys, renders much of this safety equipment unnecessary. The absence of the risk of petrol and diesel vehicle emissions, the autonomous control of the vehicles, and the need for increased power supply for such a network represents a paradigm shift in terms of the design of tunnels. In addition, specialized electronic equipment such as high-speed trolleys will need to be designed and tested as well as corresponding intelligent control equipment/systems. Reduced tunnel size will also reduce costs and speed up construction — all highlighting a need to rethink traditional design.


Tom Ireland is technical director, Transport Services and a tunneling expert at Aurecon (www.aurecongroup.com).

Posted in Infrastructure | June 1st, 2017 by

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