June 1999


Project aims to keep trucks rolling on wheels, not sides

big rig
By applying some math and measurement to semis and curvy stretches of blacktop, the Truck Rollover Warning Project could keep the big rigs sitting upright on all 18 wheels.
If you’ve ever crossed the Smoky Mountains on Interstate 40 you’ve probably seen the aftermath of a truck rollover. For whatever reason—a shifting load or too much speed into a curve—a big semi topples over onto its side.

At the very least the rig and its cargo are damaged. If you’re a truck driver, it can ruin your day.

“Rollovers cost the economy $3 billion a year. They also kill and injure people, including truck drivers,” says Scott Stevens of the Energy Division. Stevens is spearheading a project to install instruments on vehicles and tricky spots on trucking routes alike so that rollovers can be avoided. The project is enjoying a high degree of cooperation from both the trucking industry and federal highway safety agencies.

The Truck Rollover Warning Project relies on computer and radio frequency technologies to warn drivers that their impending approach to a curve in the road might lead to disaster. It’s similar to an airliner’s warning system that alerts a pilot to unsafe flying conditions. “To warn a driver, you need to know four things,” says Stevens. “You need to know the roll stability of the loaded (or unloaded) truck, which is related to its center of gravity; you need to know how bad the curve is; you need to know the truck’s speed; and you need to know where you are with respect to the curve. And it helps to know if you are braking and what the weather is doing.

“If you know all these things 1,200 to 1,500 feet ahead of a curve, you can predict whether a truck is heading for trouble.”

In that case, some sort of warning indicator would sound and alert the driver to slow down. If all this sounds a little too Buck Rogers for your idea of a truck driver, Stevens’ experience belies the notion.

“Truckers love it,” he says. “We’ve been working with a 48-state carrier, U.S. Express Enterprises, that is well known in the industry for its safety program. They have been very supportive of our project, because safety is very important to their image as a reliable and safe operator.

It’s also a bit of a dream project for Stevens, who said he worked for years to convince government transportation officials and the trucking industry that such a system was feasible and needed. “I’m an engineer and I like to measure things,” he says.

Recently Stevens, safety officials from U.S. Express and a staff member from the UT Transportation Center went on a road trip to feel out some of the worst spots on a long stretch of I-75. Some included the nearby junction with I-40 and the junction with I-24 at Chattanooga, both common sites for rollovers.

“We’ll instrument some test trucks and mark the bad the curves by putting radio beacons ahead of the curve. The trucks’ hardware includes a system known as dedicated short-range communication that is similar to electronic toll-collection devices. We will also record driver reactions—like steering and braking actions—that indicate where a driver has been startled or surprised.”

Truckers themselves are providing data.
“This is a real-service test, not a test-track demo.”

Stevens stresses that the truckers themselves are providing the data for the Truck Rollover Warning Project’s initial tests: “This is a real-service test, not a test-track demo.”

The rollover project will provide the transportation sector with invaluable data on the nation’s roadways, integrating geographic positioning system data with on-board computers. Over time, truck drivers will be able to know any major trucking route like Mark Twain’s riverboat pilots knew the Mississippi.

“There are no existing maps of curves that are precise enough to be useful for rollover warnings,” Stevens says. “We’ll generate these maps, initially for I-75, but eventually all routes could be mapped.”

Besides U.S. Express Enterprises, Stevens has received support from the Federal Highway Administration’s Advanced Law Enforcement Research Technology program, which will lend police patrol car instrument technology to the truck project. Other partners are Volvo Trucks of North America; Wabash National Corporation, which makes trailers for U.S. Express; Raytheon Photonic Systems, the Tennessee Department of Transportation, Texas Transportation Institute; and the University of Tennessee Transportation Center. The industry partners are enthusiastic, Stevens says, because safety has such an important bearing on their profits. Accidents hit hard on the bottom line. In fact, carriers believe customers are willing to pay premium rates to carriers with the best safety records.

“You’ve seen those 1-800 numbers on trucks to report unsafe driving,” Stevens notes. “The trucking people tell me they really do pay attention to those calls. If you phone in a complaint, it does get reported.”—B.C.