IIHSArlington, Virginia – Drivers in vehicles that performed well in side-impact crash tests are much less likely to die in an actual left-side crash than in vehicles that performed poorly, according to the Insurance Institute for Highway Safety (IIHS). The study only included passenger vehicles with side airbags, demonstrating that while airbags are crucial, they are far from the whole story in side crash protection.

After controlling for driver age and gender, and vehicle type and weight, a driver of a vehicle rated “Good” in IIHS tests for driver protection in a side impact is 70 per cent less likely to die in a left-side crash, compared with a driver of a vehicle rated “Poor.” A driver of a vehicle rated “Acceptable” is 64 per cent less likely to die, and 49 per cent less likely in a vehicle rated “Marginal.”

The probabilities were calculated using ratings that reflect driver protection only, and differ from IIHS’ published ratings, which reflect protection for both driver and rear-seat passenger. The study looked mainly at driver death risk, because federal crash statistics do not contain the information needed to calculate passenger risk the same way. The researchers computed driver-only ratings using the same method IIHS normally uses to rate models that do not have rear seats.

“This was our first look at how our ratings correlate with actual crash data since we started side tests in 2003, and the numbers confirm that these are meaningful ratings,” said IIHS chief research officer David Zuby. “Vehicles with good side ratings provide occupants with far more protection than vehicles that do poorly in our test.”

Side-impact crashes accounted for 27 per cent of passenger vehicle occupant deaths in the U.S. in 2009, the Institute said. Such crashes can be particularly deadly because the vehicle sides have relatively little space to absorb energy and shield occupants.

Studies of frontal crashes have also shown similar results, with drivers of vehicles with “Good” ratings in IIHS frontal offset crash tests much less likely to die in frontal crashes.

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