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  1. What are airbags?  
  2. If people use their lap/shoulder belts, do they really need airbags?  
  3. How serious does a crash have to be for a frontal airbag to inflate?  
  4. Are airbags effective? Do they save lives and reduce injuries?  
  5. Where should infants and children ride in a vehicle with a passenger airbag?  
6. What about pregnant women?
7. If a car is hit on the driver's side, do all the side airbags deploy?
8. Is there new airbag technology coming?
What are airbags?
Inflating in a fraction of a second immediately after a serious crash occurs, airbags are inflatable cushions that protect you from hitting the interior parts of your car, or in some cases objects outside your car (i.e. other vehicles or trees). The instant a crash begins, sensors begin to measure impact severity. If the crash is severe enough (that is, at or above the deployment threshold), the sensors signal inflators to fill the bags with harmless gas. The bags fill in a fraction of a second to restrain occupants.

There are several types of airbags. Most vehicles have airbags that deploy in frontal crashes to protect front seat occupants. These airbags are stowed in the steering wheel for the driver. Frontal airbags for the passenger are stored in the instrument panel.

Increasing numbers of vehicles also have airbags that deploy in side impact crashes. Side airbags are usually smaller than frontal airbags and deploy very quickly from the vehicle seatback, door, or roof to protect front and sometimes rear seat occupants. There are two major categories of side airbags: those that are designed to protect only the torso (chest, abdomen, and pelvis) and those that also include head protection.
 EXAMPLES OF AIRBAG TYPES
  Frontal dual airbag system   Side airbags to protect the torso
Additional side airbags to protect the head or head and torso
If people use their lap/shoulder belts, do they really need airbags?
People who use their safety belts may think they don't really need airbags. But they do. In serious frontal crashes, the occupant compartment and the people riding inside don't stop immediately, but continue moving forward as the vehicle's front end crushes. Frontal airbags are designed to work with lap/shoulder belts to protect the head and chest of occupants from hitting the steering wheel, instrument panel, or windshield. If people hit these hard, they can sustain serious or fatal injuries to the head and chest. By keeping people from hitting these hard interior surfaces, airbags are providing important additional protection that is maximized when used in conjunction with seatbelts. The additional protection of airbags can be even more important in side impacts where a properly belted occupant can still be struck by an intruding vehicle or object. Side airbags that offer head protection are particularly important because they may be the only thing between an occupant's head and the front of a striking vehicle or a tree. Belts offer protection in other crash types too, by preventing ejection from the vehicle.
How serious does a crash have to be for a frontal airbag to inflate?
Most frontal airbags are designed to inflate in crashes equivalent to hitting a solid barrier at 20-25 kph. Some manufacturers use different inflation thresholds depending on whether people are using their safety belts. Thresholds of 18-22 kph are typically used for unbelted occupants, but thresholds are higher -- about 25 kph -- for people with belts because the belts alone are likely to provide adequate protection up to these moderate speeds.
Are airbags effective? Do they save lives and reduce injuries?
Frontal airbags: Among belted occupants in frontal crashes, deaths in frontal airbag-equipped cars are 26 percent lower among drivers and 14 percent lower among passengers compared to vehicles without frontal airbags. Unbelted occupant deaths in frontal crashes are reduced by 32 percent for drivers and 23 percent for passengers.. Side airbags: Initial analyses of the efficacy of side airbags suggest they have reduced deaths among passenger car drivers involved in driver-side collisions by about 45 percent when the side airbag included head protection and by 11 percent when the side airbag was designed to protect only the torso.
Where should infants and children ride in a vehicle with a passenger airbag?
The back always was safest for infants and children, even before airbags, and now this is more important. Infants in rear-facing restraints should be in the back seat because otherwise the infant's head is too close to the airbag. Avoid this by making sure a baby's restraint is tightly secured to a vehicle's back seat with an adult safety belt and the child is buckled into the restraint.

There are a few instances in which a child can be seated in front in airbag-equipped cars. For example, some vehicles have sensors in specially designed restraints and passenger seats that detect rear-facing infant restraints and automatically switch off airbags on the passenger side. Also, if a passenger airbag is labeled, “advanced” (meaning it will deploy with low force or deactivate if a child is in the passenger seat) or if the airbag has been turned on manually.

Only if an adult is transporting too many children to put them all in the back seat should a child ride up front. Then make sure the seat is all the way back and the child is securely buckled in a lap/shoulder belt and sitting back in the seat. Leaning forward to, for example, fiddle with radio dials can put a child at risk from an inflating airbag. If you routinely transport too many kids to put them all in back and worry about keeping a child in the front seat sitting back, away from the airbag, you may wish to get an on/off switch. If you get a switch, remember to use it correctly and turn off the airbag when an infant or child must ride in front.
What about pregnant women?
Some women late in pregnancy may not be able to get their abdomens away from the steering wheel. Then there can be a risk of fetal injury from a frontal airbag if it inflates. Even without the airbag, there's a risk of fetal injury from hitting the steering wheel. Ideally, women at this stage in pregnancy should avoid driving. However, if you must drive while pregnant, the combination of safety belts and airbags offer your best protection.
If a car is hit on the driver's side, do all the side airbags deploy?
Typically only the side airbag on the driver's side will deploy, as well as the rear-seat side airbag on the same side, if present. If the car is hit on the passenger side, the front and rear seat side airbags on the passenger side will deploy. On rare occasions, if the crash is sufficiently severe, with multiple impacts, the side airbags on the non-struck side might also deploy.

Some manufacturers are now designing side airbags to deploy in some frontal crashes as well as side impacts. These are typically offset frontal crashes that involve rapid rotation of the vehicle, and the side airbags can help keep occupants' heads inside the occupant compartment or from hitting hard surfaces inside the vehicle. Conversely, frontal airbags may deploy to help protect occupants in side impacts. For example, if a vehicle is moving forward at the time of its side impact, this forward motion will be stopped and the frontal airbags can help prevent serious injuries.
Is there new airbag technology coming?
Airbag technology is under continuous development. For example, an inflatable curtain has been designed that would deploy in the event of a rollover crash to protect occupants' heads and prevent ejection. Another airbag has been developed that would inflate under the front edge of the seat cushion during a frontal crash, keeping motorists upright and preventing them from submarining under their safety belts. A seat belt airbag has also been developed that would provide protection for all occupants in a crash; it works by inflating the torso portion of the belt. There's even a pedestrian airbag that has been developed to deploy on the outside of a vehicle -- airbags are installed at each windshield pillar to provide head protection to a struck pedestrian. Some manufacturers also provide knee airbags which are usually mounted in the lower instrument panel. Knee airbags distribute impact forces that effect knees to reduce leg injuries. They also help reduce forces on the occupants' chest and abdomen by controlling occupant movement.
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