The three-point seat belt — the lap-and-shoulder belt used in virtually every car — was invented by Volvo engineer Nils Bohlin and introduced in Volvo cars in 1959. Volvo made the patent freely available to other manufacturers, and the design is credited with saving an enormous number of lives. In 1984, New York became the first U.S. state to require drivers and front-seat passengers to wear seat belts, and New York now requires rear-seat passengers to buckle up too.

At a glance
Inventor Nils Bohlin, Volvo
Introduced 1959
Patent Made freely available to all manufacturers
First U.S. seat belt use law New York, 1984
NY rear-seat rule All rear passengers 16+ since November 2020

Why three points?

Earlier two-point lap belts could cause serious abdominal injuries and allowed the upper body to jackknife forward. Bohlin’s design combined a lap belt and a diagonal shoulder belt anchored at a low point beside the seat, spreading forces across the pelvis and chest — the strongest parts of the body — with a buckle that could be fastened with one hand.

Sharing the patent

Volvo decided that the invention was too important to keep to itself and allowed other manufacturers to use it without paying royalties.

Seat belt laws

Seat belts were fitted to cars long before people were required to wear them. New York’s 1984 law was the first mandatory-use law in the U.S., and other states followed. New Jersey also requires belts, including for adults in the rear.

Pretensioners and load limiters

Modern belts include pretensioners, which tighten the belt in a crash, and load limiters, which allow a little controlled give to reduce chest injury. Mercedes introduced pretensioners with its airbag in 1981. Read airbag history.

Buckle up in the back

Many passengers forget the rear belt in taxis and car services. It’s both the law and the most effective protection. Read the S-Class rear-seat guide and passenger etiquette.