IIHS Critical of Passenger-Side Crash Protection in Some Vehicles
Some vehicles that have received a “Good” overall rating in the tough small overlap front crash test performed by the Insurance Institute for Highway Safety (IIHS) may not provide the same level of safety for front-seat passengers as they do for drivers. A new IIHS study finds that the same level of protection doesn’t always extend all the way across the front seat.
The IIHS study consisted of 40-mph passenger-side small overlap tests on seven small SUVs with highest-possible “Good” driver-side small overlap crash test ratings. Only one of the vehicles—the 2016 Hyundai Tucson—performed at a level corresponding to a “Good” rating on the passenger side, and the others ranged from “Poor” to “Acceptable.” Accordingly, the IIHS is considering adding a passenger-side rating as part of its “Top Safety Pick” criteria.
“This is an important aspect of occupant protection that needs more attention,” said Becky Mueller, an IIHS senior research engineer and the lead author of the study. “More than 1,600 right-front passengers died in frontal crashes in 2014.”
The IIHS introduced the small overlap test in 2012. The test is designed to replicate what happens when the front corner of a vehicle collides with another vehicle or an object like a tree or utility pole. Small overlap crashes pose a challenge because they bypass a typical vehicle’s main front structure. Since the test was introduced, 13 auto manufacturers have made structural changes to 97 models. Of these, nearly three-fourths earned a “Good” rating after the changes.
“It’s not surprising that automakers would focus their initial efforts to improve small overlap protection on the side of the vehicle that we conduct the tests on,” said David Zuby, IIHS executive vice president and chief research officer. “In fact, we encouraged them to do that in the short term if it meant they could quickly make driver-side improvements to more vehicles. As time goes by, though, we would hope they ensure similar levels of protection on both sides.”
“When structural improvements are visible only on the driver side, there are large differences in performance,” Mueller added. “But the inverse is not true. Some vehicle structures look the same on both sides, but they don’t perform the same. That’s why we can’t rely on visual analysis but need to monitor this issue and possibly begin rating vehicles for passenger-side protection.”
Passenger-Side Intrusion Poses Additional Injury Risk
The 2015 Toyota RAV4 and the 2014 Nissan Rogue were the only two of the seven vehicles to appear asymmetrical. If the Institute issued ratings for passenger-side protection, the RAV4 would earn a “Poor” rating; the Rogue would earn a “Marginal,” the IIHS said in a statement. These two vehicles had the highest amount of passenger-side intrusion. The greater the amount of intrusion, the higher the likelihood of serious injuries, according to the Institute.
Maximum intrusion in the passenger-side test was 13 inches more than in the driver-side test for the RAV4, and 10 inches more for the Rogue. The Rogue’s door hinge pillar was torn off completely, and the RAV4’s door opened. In a real crash, an open door would leave the occupant at risk for ejection, according to the Institute.
Two vehicles that appeared symmetrical, the 2014 Subaru Forester and the 2015 Mazda CX-5, also had substantially more intrusion in the passenger-side test than in the driver-side test. The other three vehicles tested had relatively similar structural performance on both sides of the vehicle. The small differences that were observed, the IIHS said, could have been caused by normal variability in test results. Moreover, almost all vehicles are to some extent inherently asymmetrical. For example, structures to secure the steering wheel and pedals may provide additional bracing around the driver-side toepan, which prevents some intrusion.
In addition to the seven passenger-side small overlap tests, IIHS engineers conducted two passenger-side moderate overlap tests on one visually symmetrical vehicle, the 2015 Honda CR-V, and one asymmetrical vehicle, the RAV4. Both vehicles would receive a “Good” passenger-side moderate overlap rating.
Mueller suggested that manufacturers might improve vehicle structure for small overlap protection by strengthening the occupant compartment—perhaps by using a different type of material or adding a few millimeters of thickness.
“We conducted the moderate overlap tests as a spot check, and we weren’t surprised that both vehicles performed well,” Mueller said. “Many of today’s models are designed for the global market and are subject to driver-side moderate overlap tests in right-hand-drive countries. With small overlap, there isn’t the same incentive for symmetrical design because we’re the only organization conducting the test.”
The IIHS could introduce passenger-side small overlap ratings next year, and make them a requirement for a safety award as early as 2018.