IIHS Says Knee Airbags Aren't Effective

Knee airbags, an increasing feature in new cars, have little effect in reducing injuries and may even increase the risk for occupants, says the Insurance Institute for Highway Safety.

The IIHS analysis looked only at injury risk for belted occupants. The institute notes that carmakers have been installing knee airbags mainly to help them pass federal crash tests of unbelted dummies.

The bags usually deploy below the dashboard and are designed to control lower body movement and minimize leg injuries in a frontal crash.

 IIHS’s analysis looked at real-world injury data from 400 real-world crashes in 14 states as well as impact data recorded by dummies in the institute’s driver-side overlap front crash tests.

In real-world crashes, knee airbags reduced the overall injury risk by a statistically insignificant half percentage point, IIHS reports. In the institute’s own crash tests, the devices provided a small improvement in injury readings for some tests, increased leg injury risk in others and no effect in some cases.