The Evolution of the Three Point Seat Belt from Yesterday to Tomorrow

The three point seat belt (the safety belt) has been in use in cars for almost fifty years. In 1959 Volvo, as the first car producer in the world, started to install three point safety belts (of the static type) for front seat occupants as standard equipment. A few years later it was obvious from car accident studies that safety belts were of considerable benefit. No other safety product has saved so many lives of car occupants as the seat belt. Other products such as frontal and side airbags have been successfully implemented to further enhance car occupant protection. However, these new restraint systems complement the three point seat belt rather than replacing it. Several improvements to the seat belt have taken place over the years. The first was the inertia reel (the belt retractor) during the 1960s, followed by the retractor pretensioner and the buckle pretensioner during 1980s. The largest improvement made so far was probably the shoulder belt force limiter introduced in 1995. The first, and an important, step into active and integrated safety was taken by Mercedes-Benz in 2002 with the belt pre-pretensioner (PRE-SAFE). Possible future improvements such as various ways to prevent car occupants' upper torso from sliding out of the shoulder belt in rollovers and in far-side impacts are discussed, as well as steps to take elderly even more into account by a further reduction of the risk of sustaining serious chest injuries in frontal crashes. More also needs to be done to prevent violent head-to-upper torso motions to reduce the risk of sustaining disabling neck injuries with long term consequences. The three point seat belt will probably remain the primary car occupant restraint system for many more years. Its protection capabilities combined with other restraint systems can be developed further, as well as improvements to its ease of use. For the covering abstract see ITRD E141569.