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SUV Safety Explained


The Hummer H2 SUT is a typical large SUV. Because of a higher likelihood of a rollover in an accident or emergency maneuver, drivers need to adopt a more conservative driving style.
The Hummer H2 SUT is a typical large SUV. Because of a higher likelihood of a rollover in an accident or emergency maneuver, drivers need to adopt a more conservative driving style.
photo courtesy of Hummer

As SUVs become more popular and account for a larger portion of vehicles on the road, SUV safety becomes increasingly important. SUV and pickup truck sales grew by more than 25 percent from 1989 to 2004. During that time, fatalities in passenger cars dropped from more than 25,000 in 1989 to 19,460 in 2003, and the number of deaths in light trucks (including sport-utilities, pickups and vans) climbed from about 8,500 annually to 12,444. Adding to the SUV safety dilemma, NHTSA (National Highway Traffic Safety Administration) and the insurance industry say death rates are higher in small SUVs than all other vehicle classes.

Since the 1999 model year, federal SUV-safety regulations have required these vehicles to meet the same major safety requirements as cars, including dual front airbags and identical side-impact standards. The only vehicles exempt are heavy-duty SUVs, pickups, and vans with gross-vehicle weights of more than 8500 pounds.

When buying an SUV, consider its safety features. These fall into two categories: active and passive. Active safety features help the driver avoid an accident, while passive safety features help protect occupants in the event of an accident. You should consider both when shopping for an SUV.

The best kind of accident is the one you never have. The following active safety features are designed to help you avoid an accident.

Antilock Brakes

Most vehicles today are available with antilock brakes (ABS). If antilock brakes do not come standard on the SUV you intend to buy, be sure to choose ABS as an option. While ABS does not help a vehicle stop more quickly on dry pavement, it has two distinct advantages. First, and most importantly, ABS allows you to steer your vehicle under full braking power. This is because ABS pumps the brakes many times per second--much faster than a human can--thus preventing wheel lockup and helping to maintain steering control. That means when a car suddenly stops in front of you, you can brake hard and still steer over to the shoulder if you won't stop fast enough to avoid an accident.

In these instances, ABS can be the difference between a fender-bender and a close call. Second, ABS can help you stop more quickly on slippery pavement. A well-trained driver may be able to pump the brakes and prevent a skid, thus stopping quicker. However, most drivers mash the brake pedal in an emergency situation, making ABS the better choice.

Antilock brakes prevent the wheels from skidding in hard braking. This allows a driver to continue to steer away from obstacles.
Antilock brakes prevent the wheels from skidding in hard braking. This allows a driver to continue to steer away from obstacles.
photo courtesy of Volvo

Antiskid Systems

An antiskid system uses various sensors to detect a skid, then works with the antilock brake system to apply individual brakes to help keep the vehicle on its intended path. In some cases, an antiskid system also reduces engine power. What does this mean to the driver? Well, if you approach a corner too rapidly and your vehicle begins to skid, an antiskid system will detect that the vehicle is not on its intended path and intervene by applying the inside brakes. This will rotate the vehicle through the turn and, hopefully, save you from going off the road.

Antiskid systems can't defy the laws of physics, so they won't help you take a 90-degree turn at 100 mph, but they can be quite helpful in most driving. Antiskid systems are available on most SUVs, but they are usually optional. Make sure to order your SUV with an antiskid system.

Roll Stability Control

Roll stability control works very much like an antiskid system, but uses additional sensors to detect an impeding rollover. It then activates the antiskid system in a manner to prevent a rollover. Roll stability control systems work on flat pavement; they can't prevent rollovers caused by hitting a curb or sliding into a ditch. Also, roll stability control should not be confused with what may be called rollover protection. These systems deploy curtain side airbags when detecting an impending tip.

All-Wheel Drive

All-wheel-drive and four-wheel-drive systems allow all four wheels to transfer power to the road. Though not generally considered a safety feature, AWD or 4WD can provide the additional traction you may need to accelerate out of harm's way.

All-wheel drive isn't normally considered a safety feature, but it can help a driver maintain control on slippery roads or accelerate out of harm's way.
All-wheel drive isn't normally considered a safety feature, but it can help a driver maintain control on slippery roads or accelerate out of harm's way.
photo courtesy of Saturn

Four-Wheel Independent Suspension

Four-wheel independent suspension allows each wheel to react individually to bumps in the road. All SUVs have independent front suspension, but not all have independent rear suspension (IRS). Those without IRS have solid rear axles that cause both wheels to react to a bump in the road when either tire hits that bump. While four-wheel independent suspension is also not generally considered a safety feature, keeping at least one tire planted on the road could possibly make the difference in avoiding an accident, especially when taking bumpy corners at high rates of speed.

Not every accident can be avoided. Should you get into an accident, it's best to have the following safety features on your side.

Airbags

Since 1994, the government has required all cars sold in the United States to have a front driver-side airbag, and dual front airbags have been required since 1997. By the 2007 model year, all U.S. cars will be required to have advanced front airbags that inflate with greater or lesser power according to the needs of the occupant. Sensors that determine the occupant's size and position, whether a seatbelt is in use, and the severity of the crash all determine the force with which the airbag is deployed. These airbags, already in use in many vehicles, are safer for children and smaller occupants than the current single-stage airbags.

Studies show that front airbags aren't always enough, though. Side-impact airbags are especially helpful in the event of a side collision. According to a 2003 study by the IIHS, head-protecting side airbags accounted for a 45 percent reduction in risk of death in side crashes. Torso-protecting side airbags reduced risk of death by 11 percent in the same study. Based on this data, safety-conscious buyers will obviously want to include head-protecting and/or torso side airbags on their SUV shopping lists.

Seatbelt pretensioners

Seatbelt pretensioners, which take the slack out of seatbelts quickly and automatically under heavy braking or in a frontal crash, are standard in most vehicles. Pretensioners help ensure that occupants get the best possible protection from their seat belts. Check to make sure the vehicle you are buying has them.

Seatbelt force limiters

When pretensioners work, they can make the belt quite taut, possibly leading to chest injuries in the event of a crash. That's where seatbelt force limiters come into play. Force limiters let a little bit of slack back out of the belt. They are designed to work with the airbag to help spread frontal crash forces across the occupant's body, thus reducing the risk of injury.

Seatbelt pretensioners and force limiters work together to reduce the impact forces transferred to an occupant in a crash.
Seatbelt pretensioners and force limiters work together to reduce the impact forces transferred to an occupant in a crash.
photo courtesy of Honda

Recent trends in higher gasoline prices have cooled sales of larger SUVs somewhat. However, compact and midsize SUV sales are still quite strong. It's very important for any prospective buyer to be aware of all the specialized SUV-safety features available and to select an SUV that incorporates all of these features.


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