About SUVs
SUV accidents preventable with adjustments
Rollover deaths predictable
The SUV battle

Automobile safety advocates push it. Automobile manufacturers resist it. Joe Kimmel invented a rating system that ranks every make and model by its propensity to rollover in an accident. Rollovers often result in fatal injuries when drivers and passengers are thrown from vehicles or crushed within.

The Kimmel Index found that the vehicles that were most likely to flip over were sport-utility vehicles (SUVs). According to the Kimmel Index, there are some SUVs that might flip over in four out of every ten accidents. Overall, Kimmel found that, among 189 models from the Year 2000, SUVs made up 17 of the 20 riskiest vehicles.

The Formula
To predict rollover propensity, the National Highway Traffic Safety Administration (NHTSA) uses the static stability factor formula. The basis of the formula is a comparison of width and height of the vehicle. Width is represented by track width - the distance between the center of two tires on the same axle. The formula measures the height of the center of gravity of the vehicle.

½ track width / height of vehicle's center of gravity

Joe Kimmel uses other factors in computing his index, primarily weight of the vehicle and past rollover incidents for different sizes of vehicles. Kimmel argues that lighter vehicles will have a greater propensity to rollover.

Automakers Fight Kimmel
Industry experts feel that the Kimmel Index is a more dependable predictor of rollover propensity, but auto manufacturers try to block its use.

Automakers fight any rating system that predicts rollover risk, including the NHTSA's static stability factor. They fight the Kimmel Index by saying that its results ignore other factors, such as driver aggressiveness and impairment.

Brian O'Neill, president of the Insurance Institute for Highway Safety, takes issue with automakers 'blame the victim' argument:

"'Let's blame all rollovers on the driver' has been the standard line out of auto manufacturers forever, and it's just nonsense. Each car type is more or less likely to roll over that another type. Consumer information provided by the federal government would be a first step, and there's a need for standards to get the most unstable vehicles redesigned."

The Facts About SUV Dangers
Nearly 10,000 people were killed in rollover accidents in 1998. In SUVs, nearly 60% of fatalities happened in rollover accidents, compared with only 20% in passenger cars.

The Kimmel Index predicts that the Chevrolet Tracker, the Suzuki Vitara, and the Toyota RAV4 all will rollover in 40% of accidents. The worst performing passenger car in the survey still will only flip over in 20% of accidents.

The NHTSA now requires that SUVs have a warning label, "WARNING: Higher Rollover Risk," and, "Avoid Abrupt Maneuvers and Excessive Speed."

SUVs have gained unwanted notoriety as hazardous vehicles. Experts show that these many of accidents are preventable with design changes. Manufacturers argues that other causes exists, and that blame should not sit squarely on the shoulders of the manufacturers.

Height vs. Width
Many SUVs have a basic design flaw. They are built higher than they are wide. Simple physics can show how this is a potential hazard. Take a box and try to tip it onto another side. If the box is higher than it is wide, it will not resist being tipped. If wider, than the box will not tip without considerable force.

So it is with an SUV. Experts show that some SUV makes rollover in up to 34% of accidents, a disastrous percentage. Fatalities increase dramatically in rollover accidents. Drivers and passengers are sometimes violently thrown from the vehicle. In other instances, the roof caves in, crushing the people inside. People are more easily trapped in rollover accidents. Those who might have escaped to get help instead die from loss of blood or other hazards that result from delayed attention.

Experts note that manufacturers could easily change design to address the greatest of their concerns. If vehicle height were equivalent to vehicle track width (the distance between the center of two tires on the same axle) and not greater, rollovers would reduce dramatically.

Manufacturers Make Changes
"There are practical limitations because of what the vehicle is designed to do," says Lance Roberts, communications manager for the Alliance of Automobile Manufacturers, which represents thirteen automakers. "You can only make a vehicle so wide or so short."

This is a recognizable protest from the automobile manufacturers. They build SUVs according to the needs of families. Nonetheless, even manufacturers admit that certain design improvements could reduce the high percentage of fatal accidents that involve SUVs.

Manufacturers are starting to add skid prevention systems, recognizing that sideways slides often lead to rollovers. BMW, Mercedes, and Toyota have made this feature standard. Ford plans to add it to the Windstar SUV next year.

Experts Say It's Not Enough
Safety expert Carl Nash, formerly of the National Highway Traffic Safety Administration (NHTSA) says that many SUV suspensions do not match the standards of passenger cars. An improvement in suspension systems would also decrease the chance of rollovers.

NHTSA also would like to see SUVs equipped with a roadway-departure sensing and warning capability. Such a system would tell drivers if they are approaching turns at high speeds and risking rollover accidents.

Roof strength is often below standard. NHTSA wants to see standards for roof strength raised to protect passengers from the possibility of being crushed inside their SUV.

Sometimes It's the Driver
NHTSA notes that SUV drivers and passengers sometimes increase their own risk.

Often, fatally injured victims of rollover accidents did not wear seatbelts. Drinking has also been involved in numerous fatal accidents. Sometimes, speeding or needlessly aggressive has increased this risk.