How do seat belts enhance safety in a vehicle?

Seat belts enhance safety in a vehicle primarily by minimizing movement during a collision. When an accident occurs, the sudden deceleration can cause an unrestrained occupant to continue moving forward at the vehicle's prior speed, leading to severe injuries or ejection from the vehicle. Seat belts are designed to secure occupants in their seats, thereby reducing the distance they travel in any direction during the impact and helping to distribute the forces across stronger parts of the body, such as the chest and pelvis.

This function is crucial in preventing the most severe outcomes of a crash, as it significantly decreases the risk of injuries from both the impact with the vehicle's interior and the potential of being thrown from the vehicle altogether. Thus, the effectiveness of seat belts as a safety feature directly correlates to their role in maintaining the occupants' positions and controlling their movement during collisions.