How do they work?
The curtain airbag activates instantaneously in the event of a side impact crash, deploying from the top of the door rails above the side window. They form a cushion between the driver or passenger and the window and stay in place if the car rolls over to protect their head.
Why do I need them?
Research conducted in the USA estimates that head protecting airbags can reduce driver deaths in the event of a side impact crash by close to 40%*. Without them, in a side impact crash there is little to protect your head from striking the side of the car or rigid objects like trees or poles.
How are curtain airbags different to other types of airbags?
Curtain airbags are one type of head protecting side airbag. There are other kinds too, such as combination head and torso designs.
Combination head and torso airbags mostly activate from the seat, but some types deploy from the door, offering you good protection to both head and body in side impact crashes. However, combination designs are less effective than curtain airbags in rollover crashes.
Most people have heard of driver airbags (or frontal airbags). While these come as standard in many cars, they do not protect you in a side impact crash. Also, side airbags without the combination of head/torso design only protect the chest and thorax area, not the head.
How dangerous are side impact crashes?
Side impact crashes at intersections account for approximately 22% of all major crash types where people are killed or seriously injured.
However, according to IIHS spokesperson Russ Rader, "Even if a head curtain airbag covers the rear seats where children are most likely sitting, it won't necessarily offer them any protection. Most children are too short to receive any protection from a curtain-type side airbag."