A seat belt, also known as a safety belt, is a vehicle safety device designed to secure the occupant of a vehicle against harmful movement that may result during a collision or a sudden stop. It functions to reduce the likelihood of death or serious injury in a traffic collision by reducing the force of secondary, by keeping occupants positioned correctly for maximum effectiveness of the airbag and by preventing occupants being ejected from the vehicle in a crash or if the vehicle rolls over. Seat belt legislation requires the fitting of seat belts to motor vehicles and the wearing of seat belts by motor vehicle occupants. More and more state legislatures are enacting mandatory seat belt laws and with this effect, thousands of deaths on the road have been prevented.

Many of the statutes state that if an occupant of the car (driver or otherwise) is not wearing a seat belt at the time of an automobile accident, then that occupant may not recover civil damages from the party who caused or created the accident. The public policy reason behind such law would be contributory negligence. Contributory negligence, a doctrine of common law states that if a person was injured in part due to his/her own negligence, the injured party would not be entitled to collect any damages from another party who supposedly caused the accident. In the United States, the pure contributory negligence only applies in Alabama, the District of Columbia, Maryland, North Carolina, and Virginia. Contributory negligence denies recovery to any party whose negligence has added to the cause of the accident in any way.

The possible unfair result has led some state legislature to adopt Comparative negligence, where the relative percentages of negligence by each person are used to determine damage recovery. Thirteen states recognize the Pure Comparative Fault Rule, which allows a damaged party to recover even if it is 99 percent at fault, although the recovery is reduced by the damaged party’s degree of fault. These states include Alaska, Arizona, California, Florida, Kentucky, Louisiana, Mississippi,