Swedish automotive safety firm Autoliv has designed a new seat belt system involving a standard 3-point belt and a supplementary 2-point belt, which they claim is 30 per cent more efficient in frontal crashes than the traditional three-point belt.
Although three-point belts reduce the overall risk for life-threatening injuries by as much as 60-70 per cent and seat belts save hundreds of thousands of lives every year, Autoliv says traditional 3-point seat belts are less efficient in roll-overs and side-impact collisions, where the occupant is sitting opposite the point of impact. In such crashes, there is a risk that the occupant's torso slips out of a three-point belt and the head violently hits the inside of the car.
The new seat belt is attached to the top of the seat and crosses the regular 3-point belt. It can only be buckled after the regular belt is buckled. In addition, Autoliv has installed a new airbag at the inside edge of the seat back, aimed at keeping the occupant in the seat.
According to Autoliv, the risk of being killed or seriously injured is currently about 50 per cent when a car is struck on the far side by another car travelling at 40 mph.
The firm claim that in its tests of the new system, the risk of such injuries was eliminated completely, because the test dummies remained firmly in the seat with an adequate distance to the vehicle's side despite a significant side intrusion.
While a four-point seat belt would offer even better protection, the need to use both hands to buckle it may reduce the number of people using the belt and consequently lead to more people being killed than with current seat belt systems.