The focus of our SmartMetro event has always been to bring together the most forward thinking minds in transport to discuss its future and this year was no different. One of the most talked about presentations earlier this month was delivered by Lars Hesselgren, Director of Research and Senior Associate Partner, PLP Architecture and the man leading research and concept design for a proposed solution that could help solve the chronic congestion faced by many of the world’s cities – Cartube. This novel idea, described as the "fusion between two technolgies – mass transport with automated cars" – will be able to circumvent urban congestion through a tunnel-based system that is immune to traffic, owing to an advanced autonomous driving system and app-based booking that gives drivers exact details on the length of journeys and the cost implications.
At the event, which this year took place in Paris, the audience asked a series of questions that helpfully Lars – and now SmartRail World – provided the answers to, narrowing in on the detail as to how Cartube could fit in a city’s architecture and how, if it went ahead, it could be the answer to so many problems.
First though, a brief description of how the Cartube could work.
A gridded network of “small” and “cost effective” bore tunnels that connects with existing road networks, electric and fossil-fuel based vehicles fitted with autonomous driving technology are digitally locked in to mimic trains with a guaranteed separation of around two metres. The technology, which already exists and is being developed by major car manufacturers, is what gives Cartube its suitability to city travel and which turns the humble motor car into a fully-autonomous “transportation pod”, one that can be stored for collection at a later date at a time arranged by the user.
This is only a brief overview, though; for a more detailed visual explanation, check out the following video.
Q. and A. with Lars Hesselgren
Q. Why do you want to travel fast? Autonomous vehicles offer the ability to have a productive time while moving, so is the case for speed there?
A. The best answer I can think of is: do you really like to spend a long time travelling? Almost all transport systems that survive have shown increased speed over the competition.
Q. You’re assuming there are four people to a car that could beat Crossrail. Isn’t your system promoting single occupancy car usage, therefore, creating more problems?
A. No you utterly misunderstand the premise. The system itself doesn’t enforce car sharing BUT it makes it possible to enforce that if it is deemed a good idea. And cars, also known as transport pods, will come in many configurations – from single pods to large vans. The key is having the digital tools to enforce any particular policy.
Q. Do you have information about how much it will cost compared with the existing conventional transport systems?
A. No but our research working on it. We expect it to be substantially cheaper since it will not need to pay for the normal metro paraphernalia: trains and individual control systems, which are already present in an autonomous car. At its root it is simply tunnels with communication devices.
Q. What about during peak times? Surely there will be too many vehicles for capacity?
A. You are completely correct, and that is why the basic premise is that you have to book – and pay – for slots. If no slots are available you can’t enter the system.
Q. Passengers want to be in control, and often take public transport when they have no other choice. How do you give control back to them?
A. Control is being given back by allowing the car to have a dual personality; the vehicle that we know so well, but with the ability to transform itself into a transport pod in a digital train. The key is that the shape doesn’t matter, only controls do. And of course the car can easily be a shared vehicle, such as Uber, taxi or communal transport pods.
Q. As Crossrail showed, London subsurface is contested, so how realistic would it be to dig enough tunnels for individual sorts of vehicles?
A. Actually the subsurface is not that congested, there is a huge amount of space down below. The issue is principally to do with avoiding tunnelling going under buildings, as far as possible. However, there are plenty of roads which have no deep structures under them and our system layout exploits that fact.
Q. How do you handle “the last mile“?
A. The last mile conveniently already exists – it’s called a road. Pretty well every premise can be reached by road so why not use it? Naturally the question arises how you get from a tunnel to the surf
ace. In many congested areas getting ramps can be tricky (although connecting into existing underpasses is an idea), so we have also looked at lift systems to do that job (just like Elon Musk’s The Boring Company idea), and in extreme situation brand new helical drop-off ’stations’.
Q. Which is the best strategy for our cities? 'Point to Point' or 'Hub and Spoke'
A. Neither. A grid is by far the best solution. The road system is topologically a grid, we just mirror that at a coarser scale. What's gonna be, in terms of people per hour, per day (pphpd), the maximum capacity of car tunnels? Metros carry up to 50.000pphpd along similarly-costing tunnels.
With normal cars travelling at 50 mph we expect 40,000pphd. This can easily be increased by more compact vehicles and increased speeds. The tunnel is very much simpler than the train tunnel in that there is no need for a steel track.
Q. What about emergencies like fire or medical urgencies in those very narrow tunnels? What about failing cars?
A. This is something we’re currently investigating. One has to remember we already have protocols for this in existing metro systems – but walking along the pavement edge is easier than along a train track. Of course vehicle breakdown can occur, although we expect every vehicle entering the system to undergo a ‘dynamic health check’ – enough juice, properly certified and so on. Electric vehicles are likely to be far more reliable – 50 moving parts as opposed to 2,000 moving parts.
Fire is a clear hazard but in many ways no different from the situation in conventional metro systems. There can still be breakdowns, we are examining two strategies – small robot pullers, or simply allowing cars to be pushed by vehicles behind. In medical emergencies the car is of course the ambulance, it will take you straight to hospital with no need for ambulance. The car is your friend and will know all about your health, this is exceedingly attractive to the older generation.
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