Ejection from a vehicle is one of the most injurious events that can happen to a person who is involved in a vehicle crash. Safety belts are effective in preventing total ejections. In 1999, only 1 percent of the occupants reported to have been using restraints were totally ejected, compared with 22 percent of unrestrained occupants. When a crash occurs, unbelted occupants continue to travel at the vehicle's original speed until just after the vehicle comes to a stop. At that point, unrestrained occupants will slam into some part of the vehicle's interior, like the steering wheel or the windshield.
Unbelted persons can also collide with each other.
In a crash, vehicle occupants tend to move toward the point of impact, instead of away from it. As a result, people in the front seat are often struck by unbelted rear-seat passengers. After an unbelted person's body comes to a complete stop, the internal organs are still moving forward. They suddenly hit other organs or the skeletal system. When used properly, safety belts reduce the risk of injury during a crash because they distribute the forces of rapid deceleration over the larger and stronger parts of the your body, like your chest, hips, and shoulders.