Heavy Duty: Vehicle Stability Systems

Stability and rollover systems: Can your fleet afford NOT to have these?

It is a nightmare come true. A fully loaded rig is rolling down a steep hill corner. It’s 3:30 in the morning. Suddenly lights sweep across the road from an oncoming car, swerving toward the middle of the road.

Instinctively, the driver quickly whips the wheel to the right, barely avoiding a collision as road side rumble strips shake the cab. But she is not out of danger. As she spins the wheel left to get back on the road, her fully-loaded trailer has begun to shift precariously, threatening to roll the truck on its side.

She tenses up, expecting the worst, but controls all around her have already sprung to action. Sensors monitoring the vehicle’s yaw, steering direction and lateral acceleration have sent instant commands to individual brakes, quickly creating opposite forces where needed to keep the truck’s heading from changing quickly enough to lose control. Her tanker full of propane is heading safely down the road again, and seemingly it is all over before it began.
Or is it?

These days, the difference between a close call and a deadly, multi-million dollar accident can be whether or not the truck has a vehicle stability system.

Accidents are the bane of a fleet’s existence. According to NHTSA, 368,000 large truck accidents killed 4,321 people and injured 77,000 in 2006. The financial damage from just a single incident can be staggering as well. According to FMCSA, a fleet must generate an extra $1,250,000 in revenue (assuming an average 2 percent profit) just to pay for a $25,000 accident.

Rollovers are among the worst because of the high probability of damage to the truck, cargo and any people involved. According to NHTSA, the proportion of vehicles that rolled over in fatal crashes was four times as high as the proportion in injury crashes and 16 times as high as the proportion in property-damage-only crashes. About half of the 700 heavy-duty truck drivers killed on the road each year die in rollover accidents, according to DOT.

The most effective way to reduce deaths from rollovers? According to NHTSA, the answer is preventing single-vehicle loss-of-control crashes, since the vehicle leaves the roadway, dramatically increasing rollover probability. This is where stability and rollover systems come in.

They automatically sense a loss of stability and can work actively to help prevent rollovers, using anti-lock braking system technologies like electronic controls and wheel motion sensors. In some cases, they automatically slow speeds by de-throttling the engine and applying individual brakes.

Purchasing vehicle stability systems can be expensive—especially for larger fleets—but the consensus among those in the industry is they are well worth the cost. Available in Europe for some time, they are still relatively new on this side of the pond, but already many fleets have seen positive returns on their investments.


James Husted of Findlay, OH-based Garner Trucking had rollover stability systems installed on 25 of his 85 2005 Freightliner Columbias a few years back after two drivers had rollovers within a week and half—thankfully while he was still spec’ing.

“I’ve been with the company 20 years and those were the second and third, so obviously that was something we wanted to look at,” Husted says.

What literally drove home the point for Husted was a test drive where he made sure the rubber met the road. Now, he’s a believer. It was an important move for his company, as he spent much of January spec’ing for 20 new trucks.

“From now on, that is part of our specs, no doubt,” Husted says. “We wouldn’t even consider ordering a new truck without one. And for the cost, it’s an absolute must.”

Small fleets don’t have much margin for error these says and equipment for two dozen trucks is expensive, so Husted says it was important to personally get a taste of what he was getting into.

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