IIHS Rolled out A New Whiplash Prevention Test

The Insurance Institute for Highway Safety hopes a new seat and head restraint evaluation will push automakers to modify head restraints and seat designs to better protect occupants from rear-end crashes.

In the first initial rounds of the test, only four of out the first 18 small SUVs tested earned a good rating.

The Audi Q3, Hyundai Ioniq 5, Subaru Forester and Toyota RAV4 were good performers in the new whiplash prevention test. The Buick Encore GX, Chevrolet Equinox, Honda CR-V, Jeep Compass, Kia Sportage, Mercedes-Benz GLB-Class, Mitsubishi Outlander, Volkswagen Taos and Volvo XC40 earned acceptable ratings.

The BMW X1 and Nissan Rogue were rated marginal, and the Ford Bronco Sport, Hyundai Tucson and Mazda CX-50 were rated poor.

The original IIHS head restraint test involved a single pulse equivalent to being struck at 20 mph by a vehicle of the same weight. The evaluation was discontinued in 2022 because automakers had improved their designs so that virtually all the vehicles tested now earned good ratings.

The new test involves a simulated rear impact that is less destructive than a crash test, with the driver seat removed from the vehicle and secured to a sled.

For the new evaluation, the measures are combined to gauge three aspects of injury prevention: head and spine support; the interaction of the head with the head restraint; and how well the seat manages the energy transferred to the occupant’s body.

Some of the criteria used in the earlier test remained were good predictors of injury claim rates at a higher impact speed, including head contact time, or how long it takes for the head restraint to reach the back of the dummy’s head, and the acceleration of the last vertebra of the upper spine where it joins the neck, according to the IIHS.

According to the institute, the research also led to the addition of several new metrics, such as pelvis displacement (how well the seat absorbs the crash energy).