Vehicle platoon tests in the SARTRE (Safe Road Trains for the Environment) project - 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 - are making progress. One major step forward was taken last week on a motorway outside Barcelona - the first-ever test drive of a road train among other road users.

The convoy drove 200 kilometres in one day. "The test turned out well. We're really delighted," says Linda Wahlström, project manager for the SARTRE project at Volvo Car Corporation.

A road train consists of a lead vehicle driven by a professional (human) driver followed by a number of vehicles. Building on Volvo's 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.

The project aims to deliver improved comfort for drivers, who can now spend their time doing other things while driving. They can work on their laptops, read a book or sit back and relax. The project also aims to improve traffic safety, reduce environmental impact and - thanks to smooth speed control - cut the risk of traffic tailbacks.

"Driving among other road-users is a great milestone in our project. It was truly thrilling," says Wahlström. The vehicles drove at a speed of up to 85 km/h. The gap between each vehicle was just six metres. "During our trials on the test circuit we tried out gaps from five to fifteen metres," relates Wahlström.

The three-year SARTRE project has been under way since 2009. All told, the vehicles in the project have covered 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.

For more information on the SARTRE project visit http://www.sartre-project.eu/