IIHS Readies New Side-Impact Crash Test

The Insurance Institute for Highway Safety is finalizing a new side-impact test intended to more accurately reflect real-world collisions by large SUV/crossover vehicles. 

Under the new test, which IIHS aims to implement next year, cars will be struck by a heavier, 4,200-lb barrier that matches the average weight of a 2019 model SUV. Impact speed is being increased from 31 mph to 37 mph, which combined with the greater weight equates to 82% more impact energy.

Carmakers have become very adept at passing the current tests, with nearly all new models earning IIHS’s top “good” scores. Only 20% of vehicles did so when the tests were introduced in 2003. The improved performance is attributed to strengthened side structures and the use of head-protecting side airbags, which now are standard in all new cars.

The better test ratings directly correlate to safety benefits, according to IIHS. The group says studies have shown that a driver of a vehicle rated “good” is 70% less likely to die in a left-side crash than a driver of a vehicle rated “poor.”

Yet side impacts still accounted for 23% of passenger vehicle fatalities in 2018. Many of these deaths occurred under crash conditions more severe than those encountered in current IIHS tests.

The new side-impact procedure likely will use the same crash dummies and collect similar information as the current test. But IIHS says it is experimenting with changes to the barrier's structure, materials and shape to better replicate the front of current pickups and SUVs.

IIHS estimates that each additional centimeter of B-pillar intrusion in a side crash means a 3% increase in the risk of death. Each additional millimeter of rib deflection, which is one of the measures recorded by the dummies in the test, increases the death risk by 10%.