Active Safety for SUVs

Over the last few decades, consumers have let it be known that safety sells automobiles. In the past, that meant designs to improve the crashworthiness of vehicles and protect occupants from crash forces. Today, major advances in safety equipment can correct driver error and avoid crashes before they occur. Twenty years ago, the car was king. Today, light trucks, minivans, pickups and sport-utility vehicles are kings of the road. These vehicles were recently under a harsh safety spotlight for their high rollover crash incidents, and the weight imbalance when a passenger car and light truck are involved in a crash. In these crashes, over 80 percent of the resulting fatalities occur in the passenger car. In answer to questions raised about the safety of these very popular vehicles, Senator John McCain convened a hearing before the Senate Science and Transportation Commerce Committee on SUV safety. Chairman McCain said he called the hearing, "to examine the incidents of death, injury, and rollover when SUVs are involved in vehicle crashes."

Safety Sells
Appearing before the committee, National Highway Traffic Safety Administrator, Dr. Jeffrey Runge said that the overall number of highway fatalities is stable or even declining slightly, but safety concerns now center on rollover fatalities. Dr. Runge added, "market forces exert a powerful influence on vehicle choice, but consumers must be informed of the relative risks among vehicles in order to make appropriate market choices."


Rollover crashes affect only about three percent of passenger vehicle crashes annually, but accounted for 8,400 fatalities in single vehicle rollover crashes in 2001 and an additional 1,700 fatalities in crashes involving more than one vehicle. Runge said the government safety ratings had spurred automakers to adapt safety technology in the past much faster than "the traditional regulatory approach." While NHTSA is encouraging voluntary steps to make vehicles more resistant to rollovers, the agency is also revisiting its regulations for door locks, roof crush standards, and rulemaking to prevent ejection out of windows during a rollover. Runge added, "Last month I suggested to the industry that they work toward a consensus on rollover sensing technologies." These systems are an "active safety" system, which electronically intervenes to help avoid a crash rather than the passive safety systems of the past, which were designed to minimize injury when a crash occurs.

Stability Control
Stability control systems rely on sensors and computers to stabilize a vehicle by monitoring wheel movement and the direction the driver is steering. If a driver's intentions and the vehicle's movement don't correspond, sophisticated electronics selectively brake individual wheels or change power supplied to wheels, helping drivers maintain control. The technology was installed on only 800,000 vehicles—or just 4.8 percent—of the 16.8 million light vehicles sold in the United States last year. A recent German study showed stability control systems could reduce single-vehicle crashes by 30 percent, including rollovers. Under the TREAD Act, NHTSA will add dynamic rollover testing to its rollover-rating scheme with a final rule in the near future.


Testifying before the Committee, Robert C. Lange, Executive Director of Vehicle Structure and Safety Integration at General Motors, said the auto manufacturer introduced an electronic stability system in its vehicles in 1997. The system is on over two million GM vehicles on the road today. Continental-Teves developed a more advanced version of its electronic stability control systems called "Active Rollover Protection." This system is designed to prevent vehicles, mainly SUVs, from flipping over in radical steering moves. The system uses sensors that measure suspension movements to determine whether a rollover is imminent, and then automatically applies the brakes in such a way as to keep the vehicle from going into a roll.