In response to the Minnesota bridge accident, our local bridge was recently inspected. As a result, travel across has been restricted to cars only and no more than three tons. When my husband and I are driving over it (it’s 2 miles in length) we discuss the local theories of what to do “just in case.” My women friends and I opt for unfastening the seatbelt and rolling down at least one window. Some keep a spare life preserver in the car. My husband has suggested that newer cars have enough inflating air bags that the car should float, particularly if the windows are closed. Will it actually work?
Um… no. The airbags do not stay inflated, they are not sealed like a balloon. They inflate rapidly, and deflate almost as rapidly.
Here is a YouTube link that shows airbags in action: http://youtube.com/watch?v=CFl6nZxxxaw
Tell you what you need, they sell tools that you can keep in your car, in a map pocket or under the seat or something, and they allow you rapidly cut a seatbelt and/or break a window. Google “vehicle escape tool”, you’ll find plenty of options.
(And, this doesn’t seem like a gender-specific problem. I don’t think I know many guys who could break out a car window when it’s submerged in water.)
Yes, you should ignore the Hollywood movie depictions of airbags. These are not pillowy-soft air cells that you can inflate at will, but instead they are automatically inflated by a chemical charge that is activated only in the event of a specific type of collision. And, as was said, they will deflate very rapidly–in the matter of a second or so, IIRC.
I agree with your “open a window” theory. This will allow water to enter the car and equalize the pressure. You may be able to open a door, and if not you can exit through the open window.
I don’t recommend unfastening your seatbelt unless you find yourself in the water.
As others have already pointed out, the airbags, even if deployed, do not remain inflated for more than a second or two. They will NOT float a vehicle.
The odds are none of this will ever happen to you, and the bridge will not fall.