This is not a picture of three idiots tailgating a truck - it's the first public demonstration of a multiple vehicle platoon, as part of the ongoing Sartre project.
The name is an acronym for Safe Road Trains for the Environment and that's exactly what it means: only the truck is actually being driven. The three cars are following it completely autonomously at speeds of as much as 90km/h - on a wet road, nogal! - with no more than a six-metre gap between the vehicles.
Volvo technical project manager Erik Coelingh said: “The aim is for the road train to be completed toward the end of 2012. By then we will have four vehicles following one lead vehicle driving at 90km/h.”
The Sartre project is not the only 'road train' project under development, but it is the only one that's focused on developing a platooning system that can be used on conventional roads in a mixed environment with other road users.
The Sartre researchers also recognise that road train technology isn't entirely a technical matter, and it includes politicians, legislators and traffic safety researchers.
The main advantage of road trains is that the car drivers can do other things while the platoon is led by a professional driver (in this case in a big van, although a distinctively-marked car could just as easily be used).
Road trains are also safer since inter-vehicle reaction response times are much quicker, and their environmental impact is reduced since the cars follow closely behind each other and benefit from the lower air drag.
This is exactly the same principle as 'drafting' in Nascar racing, where two or more cars in very close formation can go significantly faster than an individual car, without using extra power.
In this case, fuel consumption of the three cars was reduced by about 20 percent at 90km/h.
And because the platoons travel closer together than would be safe with human drivers, better use is made of existing roads, thus alleviating congestion and, possibly, reducing travelling time over a given route.
The project is led by Ricardo UK and involves technology companies in Germany, Sweden and Spain, together with Volvo, which supplies the vehicles.