If you get in a crash, the airbag is supposed to help you. But an airbag is a large bag full of pressurized hot air, meant to fill most of the space between your upper body and the steering wheel or instrument panel, that has to inflate at a very high speed.
It's common for airbags, especially older ones, to inflict minor injuries as they prevent major injuries. This post isn't about those minor injuries. After all, if an airbag gave you a burn to your wrist or minor cuts and bruises that's not ideal (that would be to be unharmed by the airbag) but you're still probably gaining a net benefit from the airbag. Nor is it about the injuries and deaths inflicted by defective Takata inflators; that's another issue entirely. This is about how properly functioning airbags can cause serious injuries, and what you can do to minimize your injuries and maximize airbag benefits.
Distance - This is the biggest factor. You could have a very large, aggressive passenger airbag, but if you're in the back seat, you won't be hurt, even if you remove the front seat, because of the large amount of space. But if any airbag - even a small, gentle one, goes off when you're at zero distance, you'll probably be hurt - and if it's an aggressive airbag, possibly worse. The farther you are from any airbag, the less likely you are to be hurt, and if you're too close, the airbag won't be as effective in preventing crash injuries. Fortunately, it doesn't take a whole lot of distance to be safe: 12 inches from the steering wheel airbag, 20 inches from the passenger airbag, and 4 inches from a knee airbag. This distance is measured directly from the center of the airbag cover to your sternum.
Here's the rub: being farther from an airbag reduces injury risk from the airbag, but once you get TOO far, the airbag loses its efficacy. An airbag is only inflated for a split second* and you need to hit it at a specific moment in time, before it loses too much of its air.
The ideal distance from a driver airbag is 12-16 inches, and 20-27 inches from a passenger airbag. At these distances, injury risk is low, and protection is maximized.
On the driver side, the bag should be pointed at your sternum, not at your head or abdomen. If you hold the steering wheel higher than "10 and 2", arm injuries can result.
Airbag Design - This is a very important factor as well. As a general rule, newer airbags have safer designs than older airbags, but there is great vehicle-to-vehicle variability. Airbags have to deploy quickly, but the faster they strike your body, the greater the impact, and remember that impact energy increases at the square of velocity - so a 200 mph airbag strike will have 4 times as much force as a 100 mph strike, and 16 times as much force as a 50 mph strike! Many pre-1998 airbags deployed at speeds nearing or over 200 mph. This was found to be excessive, so in 1998 "depowered" airbags were introduced that deployed with less force. Since the mid-2000s, "advanced" airbags have been fitted to most new cars. These airbags can deploy at different force levels depending on seat position, occupant weight, and crash severity. Refinements to the technology are still occurring. Many airbags today don't even reach 100 mph during deployment.
Aside from deployment speed, other factors that influence airbag design are airbag size, deployment geometry and fabric material. Airbags have to be big enough to cushion the body in a severe head on collision, but too big is bad. Most driver airbags made since the late 1990s have something called a tether to control their thickness. Some recent driver airbags have found ways to be safe without tethers, but as a general rule, tethers in driver airbags are a good thing. The ideal design for a passenger airbag is one that deploys initially upward and then rearward rather than directly toward the occupant.
*Side curtain airbags are often inflated for longer, sometimes several minutes.
It's common for airbags, especially older ones, to inflict minor injuries as they prevent major injuries. This post isn't about those minor injuries. After all, if an airbag gave you a burn to your wrist or minor cuts and bruises that's not ideal (that would be to be unharmed by the airbag) but you're still probably gaining a net benefit from the airbag. Nor is it about the injuries and deaths inflicted by defective Takata inflators; that's another issue entirely. This is about how properly functioning airbags can cause serious injuries, and what you can do to minimize your injuries and maximize airbag benefits.
Distance - This is the biggest factor. You could have a very large, aggressive passenger airbag, but if you're in the back seat, you won't be hurt, even if you remove the front seat, because of the large amount of space. But if any airbag - even a small, gentle one, goes off when you're at zero distance, you'll probably be hurt - and if it's an aggressive airbag, possibly worse. The farther you are from any airbag, the less likely you are to be hurt, and if you're too close, the airbag won't be as effective in preventing crash injuries. Fortunately, it doesn't take a whole lot of distance to be safe: 12 inches from the steering wheel airbag, 20 inches from the passenger airbag, and 4 inches from a knee airbag. This distance is measured directly from the center of the airbag cover to your sternum.
Here's the rub: being farther from an airbag reduces injury risk from the airbag, but once you get TOO far, the airbag loses its efficacy. An airbag is only inflated for a split second* and you need to hit it at a specific moment in time, before it loses too much of its air.
The ideal distance from a driver airbag is 12-16 inches, and 20-27 inches from a passenger airbag. At these distances, injury risk is low, and protection is maximized.
On the driver side, the bag should be pointed at your sternum, not at your head or abdomen. If you hold the steering wheel higher than "10 and 2", arm injuries can result.
Airbag Design - This is a very important factor as well. As a general rule, newer airbags have safer designs than older airbags, but there is great vehicle-to-vehicle variability. Airbags have to deploy quickly, but the faster they strike your body, the greater the impact, and remember that impact energy increases at the square of velocity - so a 200 mph airbag strike will have 4 times as much force as a 100 mph strike, and 16 times as much force as a 50 mph strike! Many pre-1998 airbags deployed at speeds nearing or over 200 mph. This was found to be excessive, so in 1998 "depowered" airbags were introduced that deployed with less force. Since the mid-2000s, "advanced" airbags have been fitted to most new cars. These airbags can deploy at different force levels depending on seat position, occupant weight, and crash severity. Refinements to the technology are still occurring. Many airbags today don't even reach 100 mph during deployment.
Aside from deployment speed, other factors that influence airbag design are airbag size, deployment geometry and fabric material. Airbags have to be big enough to cushion the body in a severe head on collision, but too big is bad. Most driver airbags made since the late 1990s have something called a tether to control their thickness. Some recent driver airbags have found ways to be safe without tethers, but as a general rule, tethers in driver airbags are a good thing. The ideal design for a passenger airbag is one that deploys initially upward and then rearward rather than directly toward the occupant.
*Side curtain airbags are often inflated for longer, sometimes several minutes.
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