A seatbelt (also known as a seat belt or safety belt) is a vehicle safety device designed to secure the driver or a passenger of a vehicle[1] against harmful movement that may result during a collision or a sudden stop. A seat belt reduces the likelihood of death or serious injury in a traffic collision by reducing the force of secondary impacts with interior strike hazards, by keeping occupants positioned correctly for maximum effectiveness of the airbag (if equipped) and by preventing occupants being ejected from the vehicle in a crash or if the vehicle rolls over.When in motion, the driver and passengers are travelling at the same speed as the car. If the driver makes the car suddenly stop or crashes it, the driver and passengers continue at the same speed the car was going before it stopped. A seatbelt applies an opposing force to the driver and passengers to prevent them from falling out or making contact with the interior of the car (especially preventing contact with, or going through, the windshield). Seatbelts are considered Primary Restraint Systems (PRS), because of their vital role in occupant safety.
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