GM to Put Stabilitrak in Large Vans
Stability control is an excellent safety system in any vehicle, but for various unique reasons it is perhaps most useful in those large vans that now serve primarily as airport shuttles and as buses for small groups.
So it is particularly helpful that GM has been putting its Stabiltrak system in its 12- and 15-passenger Chevrolet Express and GMC Savana models last year, and will add it to the short-wheelbase models this fall.
Ford has been reported to be planning the same thing for its 2006 model year 15-passenger Econoline models in 2005, but will not confirm the story.
Under any circumstances, these vehicles are more likely than almost any other non-commercial vehicle to go out of control in poor conditions (such as rain, snow, ice and uneven road surfaces) or in emergency situations and end up rolling over, thanks to their unique height and length.
But the situation is even more hazardous when they're full of people, since the extra weight raises their centre of gravity even higher. And if the weight also shifts because people in the back are unbelted and slide to one side, their handling ability can be compromised to an even greater degree.
These very issues have come into play quite often in the U.S. in recent years, resulting in many high-profile rollover crashes, including some with multiple fatalities.
As a result, two U.S. safety agencies have taken special notice.
The National Highway Traffic Safety Administration (NHTSA) has issued a pair of consumer warnings about the safety of such vehicles. NHTSA has recommended that such vehicles should only be driven by people familiar with their unique handling characteristics, and that every passenger should wear their seatbelts.
The National Transportation Safety Board has recommended that they be should be equipped with stability control systems.
Stability control systems such as GM's StabiliTrak help because they are programmed to detect the difference between the steering wheel angle and the direction the driver is actually turning by ''reading'' the steering wheel position, the amount of sideways force in play, vehicle speed and the vehicle's response to steering wheel input.
Ray Chess, GM's vehicle line executive for commercial trucks and vans, explains that StabilTrak then ''uses the brakes to enhance control of the vehicle's direction and to help keep it on course.''
Specifically, Chess says, it ''automatically reduces the engine torque and applies precise amounts of pressure to front right or left brakes to help keep the vehicle on track. These brake and engine interventions help realign the vehicle's actual path with that being steered by the driver.''