GOTEBORG, Sweden (Jan. 3, 2014) — Volvo Trucks has developed Stretch Brake, a solution to improve safety for trucks with trailers on slippery downhill stretches.
"Even if the truck driver ultimately manages to control the situation, it can be extremely unpleasant both for oncoming road users and the truck driver, if a rig suddenly veers off its intended course on a downhill gradient," said Mats Sabelström, brake specialist for the Volvo Trucks brand.
Volvo said Stretch Brake automatically retards the trailer and straightens up the rig on downhill grades.
"About 15 percent of the total of 30,000 serious road accidents in Europe every year involve trucks, in a slightly declining trend," said Carl Johan Almqvist, traffic and product safety director for the Volvo Trucks brand.
"With effective brakes, stability systems and collision warning systems we are already helping drivers avoid risky situations in difficult conditions. Stretch Brake is yet another important part of our long-term drive to increase traffic safety and minimise the number of accidents involving trucks."
Volvo said Stretch Brake is a complement to the rig's electronic stability program (ESP) — another Volvo Trucks system. While ESP is at its most effective at higher speeds, Stretch Brake is operational only at speeds below 25 mph. Both systems contribute to better stability and easier steering.
Stretch Brake features include:
- Increases safety on downhill gradients, especially on slippery roads and in curves.
- Applies the drawbar brakes in a pulsating mode.
- Straightens the rig, makes steering easier and reduces the risk of jack-knifing.
- Operational at speeds below 40 km/h.
- Introduced in 2012 on Volvo FH trucks and in 2013 on Volvo FM trucks.
In 2014 Stretch Brake will also become available on tractor/semi-trailer rigs.
"One might call Stretch Brake a kind of low-speed ESP," Mr. Sabelström said.
"As the rig approaches a downhill slope, the driver manually activates the system. When the driver then releases the accelerator, the brakes on the trailer are automatically applied in a pulsated mode all the way down the hill until the gradient levels out and speed can once again be increased."
According to the Volvo Trucks Accident Research Team, which specializes in studying traffic safety, about 60 or so of the truck accidents that occurred in Sweden alone last year could have been avoided with Stretch Brake2.
"Drivers who have tested Stretch Brake came away very impressed with the system. As we now also introduce the system on tractor-semitrailer rigs even more drivers will be able to negotiate difficult downhill gradients both more simply and safely," Mr. Almqvist.