How good it would have been if accidents had not caused any injury. But accidents are something, which cannot be prevented and can occur anytime. The degree of injury due to an accident may vary from unrecoverable injury to minor injury. While driving, Rollover Accidents is one of the worst forms of accidents that could cause major injuries. In US, around 10,000 people are killed annually in rollover crashes.
Autoliv Inc. -- the pioneer in automotive safety - has introduced a new seat belt and an airbag system for rollover protection. According to their test, the system is capable of reducing virtually all-serious head and neck injuries in rollover crashes, as long as the roof of the vehicle withstands the ground impact without extensive intrusion. In vehicles fitted with rollover sensors, the seat belt pretensioners could also be activated to tighten the seat belt, thereby increasing the distance between the occupants head and the roof of the vehicle.
Autoliv has also fitted a small airbag at the inboard side of the backrest side (i.e., on the right side of the driver seat on a left-hand driven vehicle). This curtain airbag is designed to give protection only on one side of the occupant. When an occupant moves towards the other side of the vehicle during the rollover crash, the upper body could slip out of the shoulder belt, due to which a greater risk of injury emerges. In order to reduce slack the seat belt is also tightened up to 15 centimeters (6 inches) using a pyrotechnic seat belt pretensioners. In addition to the new seat belt and an airbag system for rollover protection, autoliv has also developed a special sled test rig. With it, the companys researches can simulate a typical rollover when the vehicle rotates half a turn and then capsizes. Only the body of a car or an SUV is needed for the test, which makes testing less expensive than traditional method of full-car testing. The test rig simulates all three phases in a typical rollover such as tripping, air born and ground impact. Hence, use of simulation gives an idea about all possible complex motions of human body in a typical rollover without using real vehicles. Autoliv also found it necessary to modify dummies because their spines are stiff and rigid. In humans, however, the spine is curved and therefore the distance between the head and the hip often increases a little when the occupant is turned upside down in a rollover. Hence, the spines of the test dummies have been modified to provide the correct elongation characteristics.