Steering Toward Rollover Prevention
The number of deadly vehicle rollover crashes could be dramatically reduced by an invention that has won popularity in Europe but is not widely known in the United States, a study to be released today indicates.
The Insurance Institute for Highway Safety studied U.S. accident data and found that vehicles with electronic stability control as standard equipment were only about half as likely to be involved in fatal single-vehicle crashes as identical models without the technology.
Although many drivers fear colliding with another vehicle, single-vehicle accidents are statistically the most common type of fatal crash. Rollovers account for about half of the deaths of drivers and passengers in single-vehicle crashes.
Researchers estimated that more than 7,000 lives could be saved each year if all vehicles on U.S. roads had stability control. Last year, 42,643 people died in traffic accidents.
“In terms of effectiveness, I think it compares favorably to things like seat belts and side air bags,” said Susan Ferguson, senior vice president for research at the institute, a safety advocacy organization based in Arlington, Va.
However, the study found that the technology had little or no effect on reducing the risk of crashes involving two or more vehicles.
Nonetheless, stability control represents a new stage of development for automobile safety systems, Ferguson said.
“Seat belts and air bags are crash-worthiness technologies -- if you get in a crash, they will help you survive it,” she said. “What electronic stability control does is help you avoid the crash in the first place.”
Stability control systems constantly monitor whether a vehicle is traveling in the direction in which the driver is steering. If sensors detect a deviation, as in a skid, a small onboard computer takes over. It quickly applies the brake to an individual wheel for an instant to get the vehicle back on track. The computer can also reduce engine power.
“The driver doesn’t have to do much, other than ride it out,” Ferguson said.
The systems cost about $300 to $500 and are starting to be installed in some sport utility vehicles and luxury cars. They work in tandem with antilock brakes.
The institute’s study involved several 2000-2001 SUV and car models, including the Toyota 4Runner and the BMW Z3 roadster. Researchers analyzed crashes reported to police in seven states in 2000 and 2001.
The most noticeable benefits of stability control would likely come from preventing rollover crashes that involve SUVs. However, drivers and passengers in all types of vehicles would gain additional protection. For example, stability control could prevent a passenger car from leaving the road and striking a tree.
In Europe, stability control is built into about half of the new vehicles sold, compared with about 10% in the U.S., according to one system manufacturer. German and Swedish car makers were early converts to the technology and were more likely to offer it as standard equipment.
Though stability control is available on an increasing number of vehicles sold in the U.S., it is usually offered as optional equipment. For example, the 2005 Ford Explorer has the technology as standard equipment, but it is optional on Ford’s larger Excursion.
Lack of awareness about the benefits of the technology may explain why U.S. consumers have not embraced it, experts said.
American car buyers may also be confused by the array of brand names that manufacturers use for their versions of the technology. “When you go into the showroom, they all have different names,” Ferguson said. Ford calls its system AdvanceTrac, and General Motors uses several brand names, including StabiliTrak, Active Handling and Precision Control. Toyota calls it Vehicle Stability Control and Mercedes-Benz uses ESP, or Electronic Stability Program.
“It would be nice if we could all agree to call it electronic stability control,” Ferguson said. “A single way of referring to it would help to educate the public.”
Studies by the federal government have found potentially dramatic benefits from stability control. In preliminary findings released last month, the National Highway Traffic Safety Administration said the technology reduced fatal single-vehicle crashes by 63% in SUVs and by 30% in passenger cars.
The agency is conducting more tests on the technology, and has not decided whether to propose regulations that would require automakers to install the systems.
“We may look at rule-making in the future, but we feel we need more research first,” said NHTSA spokesman Rae Tyson. There are “no immediate regulatory plans,” he added.
