Second only to frontal collisions, side collisions are one of the most dangerous accident types for passenger vehicles. The force of these impacts can cause vehicle occupants to be thrown sideways, relative to the vehicle, against the door or other objects outside of the vehicle. In fact, this type of collision causes almost 20% of passenger car fatalities according to the Institute for Traffic Accident Research and Data Analysis in Japan.
SRS side and side curtain airbags help to protect passengers in side impact collisions by working to restrain the head and chest while cushioning the impact of colliding with the vehicle’s door and frame. According to studies by the Insurance Institute for Highway Safety, these technologies have helped reduced the fatalities from side collisions by almost 40%.
Toyota helped pioneer the use of SRS side curtain airbags, which help protect the head against serious injuries in certain types of side collisions. After developing the technology to store an airbag in the limited space of the roof rail, and then conducting rigorous testing to help confirm it would deploy quickly between the head and side glass, Toyota included the feature in the 1998 ‘PROGRES’ safety system.
How does it work?
Side impact collisions have a completely different profile from frontal collisions, so require different technologies to help protect passengers. In side impacts, the door can potentially intrude into the cabin space quickly, requiring airbags to deploy even faster.
When installed, SRS side airbags work with a sensor stored in the center pillar of the vehicle, which monitors for an impact exceeding a certain magnitude at the time of collision. In a collision, side airbags stored in the seatbacks deploy in .02 seconds, while side curtain airbags stored in the roof above the side glass deploy in .03 seconds. In rollovers, special roll-sensing curtain airbags installed on some model vehicles deploy and remain inflated for three to five seconds. Together, these airbags help to reduce the impact that the head and chest can receive when colliding with a door or other objects outside the vehicle.