What it is: Frontal airbags, or airbags, are inflatable cushions (bags of inert gas) that help slow the rate of deceleration for the driver and front passenger during a frontal collision.
How it works: The driver and front passenger's airbags are stored in compartments in the steering wheel and instrument panel, respectively. In a collision that exceeds a preset level of forward deceleration (determined by crash sensors located in the vehicle), a pyrotechnic gas generator is ignited and, in a few milliseconds, generates nitrogen gas that deploys and fills the airbag. By the time the occupant has moved forward toward the airbag, it is ready to cushion them.
The latest frontal airbags have dual-rate inflators that deploy at different rates depending on the severity of the crash-faster deployment for high-speed impacts and slower deployment for low-speed crashes. In addition, some systems are sophisticated enough to differentiate between large and small passengers and adjust their deployment rate to suit. Some Lexus airbags have a two-chamber design that helps keep the passenger centered during an accident.
How it benefits the passengers: It is important to note that frontal airbags are not a replacement for seatbelts. When used in conjunction with seatbelts, however, they have been shown to help reduce the severity of injuries in frontal accidents.