SARTRE - automated car trains

The automotive industry has long been focused on the development of active safety systems that operate preventively, such as traction control and braking assistance programs. But automakers have also gone much further in proposing technology that allows vehicles to be operated without any input whatsoever from the person behind the wheel. Known as autonomous driving, this technology means that the vehicles is able to take control over acceleration, braking and steering, and can be used as part of a road train of similarly controlled vehicles.

The first test cars equipped with this technology will roll on test tracks as early as 2011. The vehicles will be equipped with a navigation system and a transmitter/receiver unit that communicates with a lead vehicle. Since the system is built into the cars, there is no need to extend the infrastructure along the existing road network.

The idea is that each road train or platoon will have a lead vehicle that drives exactly as normal, with full control of all the various functions. This lead vehicle is driven by an experienced driver who is thoroughly familiar with the route. For instance, the lead may be taken by a taxi, a bus or a truck. Each such road train will consist of six to eight vehicles.

A driver approaching his destination takes over control of his own vehicle, leaves the convoy by exiting off to the side and then continues on his own to his destination. The other vehicles in the road train close the gap and continue on their way until the convoy splits up.

The road trains increase safety and reduce environmental impact thanks to lower fuel consumption compared with cars being driven individually. The reason is that the cars in the train are close to each other, exploiting the resultant lower air drag. The energy saving is expected to be in the region of 20 percent. Road capacity will also be able to be utilized more efficiently.

There is still plenty of work to be done before we see road trains hit the streets. A three-year research trial will determine how to build a wireless system without making costly changes to highway infrastructures. Ideally, all vehicles linked in behind the driver move automatically, and cars can exit the platoon whenever they want. The trial will also look at safety issues — for example, how to make sure a car doesn’t end up sandwiched between two giant trucks.

If all goes well with the research trials, SARTRE will begin test runs on tracks in Sweden, the UK, and Spain. Soon after that, public road trials will begin. So if you see a group of distracted drivers moving in a perfectly straight line down the highway, don’t worry — they might be in wirelessly controlled vehicles!