Got in a collision in an 04 Forester this weekend...?

Question

...and the airbags did not deploy. I was on the highway and rear-ended a van just before a tollbooth. I did manage to brake and slow myself down a lot. The front end of my car was mashed in, but I was slowed enough that my purse didn't fall out of the back seat. How fast do you need to be going for airbags to deploy? Is it possible I was slowed down enough, or is there likely something wrong with my airbags?

Answer 1

Airbags are designed to deploy only when they might be needed to prevent serious injury. In order for airbags to be effective they must deploy early in a crash; in a frontal crash this typically occurs within the first 50 milliseconds (0.05 seconds).

A vehicle's airbag control module relies on feedback from crash sensors to predict whether an event is severe enough to warrant an airbag deployment.

Frontal airbags are designed to inflate in moderate to severe frontal crashes. Some manufacturers use different inflation thresholds depending on whether people are using their safety belts.

One threshold used by airbag designers is "must deploy" which includes a situation such as an impact into a rigid wall of 10-12 mph for unbelted occupants.

The "must deploy" threshold is slightly higher — about 16 mph — for belted occupants because the belts alone are likely to provide adequate protection up to these moderate speeds.

Answer 2

I think you have to hit something at over 10 mph for them to deploy.  Not sure what it is for your particular vehicle.