What is the main purpose of a seatbelt?

The main purpose of a seatbelt is to prevent serious injury in an accident. In the event of a collision or sudden stop, a seatbelt restrains the occupant of the vehicle, minimizing the risk of injury by keeping them securely in place. This is crucial because, during a crash, unbelted occupants can be thrown forward or ejected from the vehicle, significantly increasing the likelihood of severe injuries or fatalities. Seatbelts are designed to distribute the force of a crash across the stronger parts of the body, thereby reducing the potential for harm.

While keeping you from falling out of the vehicle is a secondary benefit, the primary function focuses on safety in the context of an accident. Speeding up arrival at a destination is not related to the use of seatbelts, nor is comfort while driving a primary consideration for their design. The emphasis is squarely on safety and injury prevention during travel.