When you are involved in an accident, sensors monitor the severity of the collision, and use that data to decide whether to deploy the Airbags . If a certain severity threshold is exceeded, the bags fill with gas. This entire process occurs within a fraction of a second. Since 1999, when the federal government mandated the installation of driver and passenger airbags, the technology has saved thousands of lives.
Yet few people know much about the bags, or the technology that powers them. We'll clarify a few common questions below.
Where Are They Installed?
Long ago, the bags were only installed in the steering wheel and instrument panel (for the driver and front passenger, respectively). While these locations are still used today, automakers also install them elsewhere. Knee bags may be installed within the lower instrument panel; side bags might be installed in the seat, door, or roof of the vehicle. These are designed to protect the car's occupants from being injured from a side collision since such collisions may harm those who are wearing seat belts.
How Do They Work?
Both frontal and side airbags work in a similar manner. As noted earlier, sensors constantly monitor the vehicle, and send data to a control module. The control module decides whether current conditions justify deployment. If it determines the impact of an accident is sufficiently severe to pose injury to the car's occupants, it triggers the mechanism that fills the airbags with gas.
Frontal bags, when they deploy, inflate to varying degrees. Much depends on the speed the vehicle is traveling, size and position of the occupant, and whether the occupant is wearing his or her seat belt. Depending on these factors, the bags inflate with a variable level of pressure and power.
The main differences with side airbags are that they are deployed more quickly and at a lower severity threshold. The reason is because a car's occupants are seated more closely to the windows and doors than the windshield. Thus, during a side collision, the potential for injury is higher.
Are They Dangerous?
Airbags can cause injury, though such incidents are rare. The force of the bags' deployment, when combined with the forward motion of a car's occupant, can result in lacerations, bruises, or worse. The problem was more prevalent during the early 1990s, however. Since then, automakers have depowered their respective systems to minimize the threat of harm.
Have Airbags Caused Fatalities?
According to the National Highway Traffic Safety Administration (NHTSA), there have been nearly 300 deaths attributable to frontal airbags between 1990 and 2008. The NHTSA study goes further to clarify that 90 percent of the fatalities were young children who were either unbelted or positioned improperly in car seats. As mentioned above, automakers have made changes to their deployment systems to reduce - and potentially, eliminate - the danger.
To date, the NHTSA has been unable to confirm any fatalities attributable to side airbags. This is likely because side bags are smaller, and deploy with much less force.
Can The System Be Turned Off?
Yes, for now. Automakers currently install airbags in their vehicles with an on-off switch. This switch allows drivers the flexibility to disengage the feature if they feel it poses excessive risk. This is primarily relevant to drivers who suffer certain health conditions. The federal government has mandated, however, that by September 2012, airbags must be installed without the on-off switch.
It's important to realize that airbags, while having caused injuries and deaths in the past, are much safer today. Automakers have striven to design their systems to ensure drivers and passengers are protected from all types of potential harm.