Volvo's SARTRE road train project has completed the first public tests on a motorway in Spain.
The first-ever public test drive of a road train comprising a Volvo XC60, a Volvo V60 and a Volvo S60 plus one truck automatically driving in convoy behind a lead vehicle was completed successfully on a motorway outside Barcelona.
"We covered 200 kilometres in one day and the test turned out well. We're really delighted," said Linda Wahlström, project manager for the SARTRE project at Volvo Car Corporation.
A road train consists of a lead vehicle driven by a professional driver followed by a number of vehicles.
The vehicles drove at 85 kilometres an hour, with a gap between each vehicle of just six metres.
Building on Volvo Car Corporation's and Volvo Technology's already existing safety systems - including features such as cameras, radar and laser sensors - the vehicles monitor the lead vehicle and also other vehicles in their immediate vicinity.
By adding in wireless communication, the vehicles in the platoon "mimic" the lead vehicle using Ricardo autonomous control - accelerating, braking and turning in exactly the same way as the leader.
Volvo says the project aims to deliver improved comfort for drivers, who can now "work on their laptops, read a book or sit back and enjoy a relaxed lunch" while driving.
It also aims to improve traffic safety, reduce environmental impact and cut the risk of traffic tailbacks.
"Driving among other road-users is a great milestone in our project. It was truly thrilling," Wahlström said.
"During our trials on the test circuit we tried out gaps from five to fifteen metres."
The SARTRE project has been under way since 2009 and is a joint venture between Ricardo UK, Applus+ Idiada, Tecnalia Research & Innovation, Institut für Kraftfahrzeuge Aachen (IKA), SP Technical Research Institute, Volvo Technology and Volvo Car Corporation.
The vehicles in the project have covered a total of about 10,000 kilometres.
After the test on the public roads in Spain, the project is now entering a new phase with the focus on analysis of fuel consumption.
"People think that autonomous driving is science fiction, but the fact is that the technology is already here," Wahlström said.
"From the purely conceptual viewpoint, it works fine and road train will be around in one form or another in the future."