Currently reading: Innovative underground Cartube network could solve city traffic issues
Using autonomous electric cars in an underground road network could drastically reduce congestion in global cities
Sam Sheehan
3 mins read
2 December 2016

A London-based architecture company has developed a traffic-beating transport solution for cities that uses autonomous cars in underground tunnels.

PLP Architecture’s so called Cartube, revealed today at the Institution of Mechanical Engineers in London, would use an artificial intelligence central control system to manage driverless electric vehicles. The vehicles would travel in a platoon and take passengers from door to door, meaning they’re an alternative to private cars rather than public transport.

“One of the big issues of urban transport is that in order to have a large capacity system you need segregated tracks [like a motorway], but cities are not segregated,” PLP Architecture director of research Lars Hesselgren told Autocar.

“You can’t have roads like these in places like London because of the many road intersections and traffic lights. So we did the very simple thing of calculating how many people you could move using an underground solution, and it turns out our estimate for Cartube is double what something like Crossrail can do.”

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Hesselgren’s team worked out that due to the frequency of station stops, Crossrail can only carry 18000 passengers an hour. But an underground road system that used 40mph vehicles could take 40,000 passengers in the same time.

“We’ve got 3 billion people [globally] to move into urban areas between now and 2050,” continued Hesselgren. “There is a crying need for technology that can actually solve this issue. When it comes to major cities that are already congested with a huge amount of buildings, the best solution is to put the transport underground.”

Hesselgren explained that using electric vehicles would significantly reduce ventilation issues and placing them underground would free up space on the surface previously taken up by roads. He said the artificial intelligence technology used to control the cars would need to recompute the whole system 100 times every second.


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“But that is actually quite trivial because if you’re steering all of vehicles, you know in advance where they are going to be in one minute’s time, 10 minutes and so on,” he said. “It means they can constantly adjust themselves so the system can work effectively at all times.”

In short, this would eliminate the prospect of traffic jams and mean vehicles would flow smoothly from place to place. A prototype Cartube road map has been designed for London, and connects vehicles to existing motorway networks that lay outside of the city.

But while the world’s most developed cities are often the ones most in need of a system like this, Hesselgren believes it’ll be the emerging locations that are most likely to find his idea exciting.

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“Urban traffic planners [in developed cities] are still going through the same plans as they were 30 years ago,” he said. “I [therefore] suspect Britain is probably going to be quite late in the process [to consider Cartube], but a country that wants to skip a generation of technology will take it up.”

Hesselgren said that rather than building six lane motorways and essentially fast tracking themselves to the unsustainable transport scenarios of developed cities, emerging cities will want to invest in futuristic solutions like Cartube.

“Cities are now having to compete with each other, and the first city that puts this in place and makes it work is going to be very competitive on a global scale,” he concluded.

PLP Architecture now hopes to attract a technology investor, like Google or Apple, to work with in the development of artificial intelligence software. If it secures a leading brand in the field, it believes the technology could be ready within five years.

Join the debate


2 December 2016
"London-based architecture firm discovers subway is best way to move people through cities". Seriously, if this thing moves more people than Crossrail, it's because it's far longer than Crossrail on its own (as opposed to a part of the Tube system).

Any follower of major transit developments knows that tunneling is far and away the most expensive component of a project. Add on the logistical element of essentially building a second tube system which is utterly incompatible with all the rail which is already down there, and this scheme reveals itself as another metro-but-not-a-metro-we-swear.

2 December 2016
I can't help feeling that some people just don't get the future, disruptive technologies and the sharing economy.
We don't need to invest billions in infrastructure projects like a Tube network for cars if we share what we will have. We have a massive motor vehicle contingency which spends 95% of it's life blocking a parking space. Imagine how that resource could redeploy as an autonomous vehicle pool.
I hear naysayers shouting in their distant past but as personal transport, particularly in cities, becomes more commodotised, what better than to have an affordable, personal, chauffeured vehicle at your command 24/7 which comes to your door, delivers you to your destination and at all other times is someone else's problem.
And we can all share in this economy while still owning vehicles which we desire for other times etc.

Evolve or die!

2 December 2016
1stdarkhorse wrote:

We don't need to invest billions in infrastructure projects like a Tube network for cars if we share what we will have. We have a massive motor vehicle contingency which spends 95% of it's life blocking a parking space. Imagine how that resource could redeploy as an autonomous vehicle pool.

A fleet of autonomous vehicles doesn't reduce congestion without schemes like this though. It'll actually add to it if cars that would normally be parked are out on the roads, conveying people who'd normally take the train or bus.

Back to the car tube topic, the idea sounds great, but as Aquaticko mentions, the cost would surely be gargantuan.

2 December 2016
I struggle to see how this would work. A 'tube' with cars in it, needs ways of allowing access by emergency crews in case of accident or mal-function. So would there be another tube beside it for that purpose ? Also, at the end of their journey, the car would need to stop to get off the system. How could that work ? Do the cars behind it have to stop too?

2 December 2016
Wouldnt London collapse into a sinkhole if anymore tunnels were made underneath it ?

2 December 2016
How on earth is this going to be built given all the sewers, tube lines and other utilities under London and other cities?

2 December 2016
devil's advocate wrote:

How on earth is this going to be built given all the sewers, tube lines and other utilities under London and other cities?

Exactly. The reason that established cities are not going to be likely to go for this kind of 'solution' is because there is so much infrastructure already underneath our cities. You'd have to dig down a mile to reach virgin soil, if you could find any at all.

2 December 2016
What other explanation could there be for such a half arsed idea? Is there really an "Institution " of idiots in London that receives funding for such concepts? Might I humbly suggest the money be better spent elsewhere? And those responsible be committed to a different institution?
But I did love the Autocar report vaguely welcoming such a proposal, presumably thinking the trillions of dollars required and decades of tunnelling would just happen autonomously?

2 December 2016 the flying cars story a few weeks ago in Autocar, a completely made up "story" to draw in readers as click bait for web advertiser billing. But I am not that cynical, or am I?

2 December 2016
A huge part of any congestion problem can be solved by not having 100's of thousands of people sitting in front of PC's in office blocks throughout cities. A lot of what they do can be done remotely from home. Not possible for all jobs but a relatively simple solution with a relatively small cost.


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