NHTSA Survey

• Exact seat belt statistics vary based on the type of vehicle, the type of seat belt, the position of impact, and whether the driver is a front or backseat passenger. A National Highway Traffic Administration (NHTSA) survey, conducted between 1986 and 1999, showed that seat belts prevent death and injury most in rollovers and rear impact crashes. However, even in nearside and side impact collisions, seat belts alone were found to reduce the incidence of fatalities.
  
  According to a 2005 NHTSA survey, proper seat belt use prevents over 15,000 vehicular deaths a year. If everyone wore a seat belt, almost 6,000 additional lives could be saved. The amount of serious injuries that proper seat belt use prevents is even higher.
  
  

Statistics

• In passenger cars, seat belts worn by front seat passengers reduce vehicular fatalities by 45 percent. That number is even higher in light trucks, where proper seat belt use reduces death incidence by 60 percent. When you break those numbers down by the type of accident, the results are even more dramatic. For rollovers (an especially high risk for light trucks), seat belts reduce death by over 80 percent in trucks, and nearly 75 percent in cars.
  
  Not all seat belt types offer the same level of protection. The 2-point belt reduces death by 32 percent, but the 3-point belt (over the shoulder and around the waist) reduces death by 48 percent. These statistics also highlight the importance of wearing your seat belt properly. Kids may not like to wear the shoulder strap, but without the shoulder strap, a 3-point belt effectively works as a 2-point belt. Therefore, the protection offered by the seat belt is compromised.
  
  

Physics

• If you're still skeptical that seat belts actually prevent injuries, consider basic physics. When a car crash occurs, the momentum will throw the passengers in the car in a certain direction, based on the position of impact. Without a seat belt, the only way the body's momentum can stop is if it hits the steering column, window or windshield. Furthermore, a seat belt not only stops the body's momentum before it hits anything, it also increases the body's overall stopping distance, which in turn dampens the force of impact. Stretching seat belts are especially effective since they increase the body's stopping distance by a greater degree than non-stretching seat belts.