For the first time ever a convoy of self-driven cars has operated on a public motorway among other road users, the historic test carried out on a motorway outside Barcelona, Spain, saw the cars wirelessly linked to a lead vehicle covering a distance of 200km.

The lead vehicle and four trailing vehicles – consisting of a Volvo S60, Volvo V60 and a Volvo XC60 plus a truck – made up the historic road train test which engineers from Volvo and Ricardo pronounced as a success.

The SARTRE (Safe Road Trains for the Environment) project is a joint venture between Ricardo UK Ltd, Applus+ Idiada, Tecnalia Research & Innovation, Institut für Kraftfahrzeuge Aachen (IKA), SP Technical Research Institute, Volvo Technology and Volvo Car Corporation. It uses existing safety systems – including features such as cameras, radar and laser sensors – and the vehicles monitor the lead vehicle and also other vehicles in their immediate vicinity.

Rather worringly, the projects cites its benefits as improved traffic safety, reduced environmental impact and – thanks to smooth speed control – reduced risk of traffic tailbacks. Environmental benefits arise from the smoother throttle control, but also because the vehicles run 6 metres apart and therefore create less aerodynamic drag.

Of course accidents do happen, and because the system rules out the possibility of independent decision – either all vehicles in the road train crash or none of them. Mathematicians will tell you that the probability of having an accident is that much less than with a road full of independently driven cars, but I’d personally rather take my chances.

The project also talks about improving driver comfort, although you’ll note that’s also one of the constraints to the technologie’s adoption (namely, drivers and passengers trusting the system), but nevertheless one of the project aims to enable drivers to now spend their time doing other things while driving – is it just me that’s shouting WHY??

The in-car entertainment options being tested include working on laptops, reading a book or sitting back and enjoying a relaxed lunch – all very civilised choices. But we’re not in Kansas anymore, so its perhaps more likely that people would take the opportunity to get wasted, sow their oats and then fall sleep. Sounds like a major contribution towards road safety..

“We covered 200 kilometres in one day and the test turned out well. We’re really delighted, It was truly thrilling” said Linda Wahlström, project manager for the SARTRE project at Volvo Car Corporation.

During our trials on the test circuit we tried out gaps from five to fifteen metres. We’ve learnt a whole lot during this period. People think that autonomous driving is science fiction, but the fact is that the technology is already here. From the purely conceptual viewpoint, it works fine and road trains will be around in one form or another in the future.

We’ve focused really hard on changing as little as possible in existing systems. Everything should function without any infrastructure changes to the roads or expensive additional components in the cars. Apart from the software developed as part of the project, it is really only the wireless network installed between the cars that set them apart from other cars available in showrooms today.”

So, the road train is a conceptual reality but not yet practical – since it would require a revamp of our road traffic laws, how we assign liability in the case of accidents and not to mention how the flow of traffic would work with a mixture of road trains and independent vehicles.

The engineers see an exciting future in SARTRE, but for many car enthusiasts it’s the perfect illustration of driving hell.