Airbags are one of the most important safety innovations of recent decades. They provide crucial cushioning for people during a crash. The devices are normally hidden from view but inflate instantly when a crash begins. Thanks to the advocacy of IIHS and others, frontal airbags have been required in all new passenger vehicles since the 1999 model year. Side airbags aren't specifically mandated, but nearly all manufacturers include them as standard equipment in order to meet federal side protection requirements.

Both frontal and side airbags save lives. Frontal airbags reduce driver fatalities in frontal crashes by 29 percent and fatalities of front-seat passengers age 13 and older by 32 percent. Side airbags that protect the head reduce a car driver's risk of death in driver-side crashes by 37 percent and an SUV driver's risk by 52 percent.

Engineers keep finding new ways to use airbags. Some vehicles now have rear-window curtain airbags to protect people in back seats or front-center airbags to keep drivers and front-seat passengers from hitting each other in a crash. There are also inflatable safety belts aimed at reducing rear-seat injuries.

Side airbag availability
by make and model

Shopping for a used car? In addition to good crash test ratings, you’ll want to look for side airbags that protect both the head and torso.