40,000 people die each year in car accidents, the leading cause of death for people under the age of 35. The number injured or maimed is significantly higher.  Safety belts can prevent death and injury in about half of these accidents. If you know this and are still not wearing a safety belt, you may need to ask yourself why not. But first, let's look at what happens when a car crashes:

The Human Collision
Imagine running as fast as you can - into a wall. You'd expect to get pretty banged up. Do you think you could stop yourself if the wall suddenly loomed up when you were two feet away from it? This is exactly the situation you face when the front of your car hits something at only 15 miles an hour. The car stops in the first tenth of a second, but you keep on at the same rate you were going in the car until something stops you - the steering wheel, dashboard or windshield - if you're not wearing your safety belt.. Bad enough at 15 miles an hour, but a 30 miles you hit "the wall" four times as hard as you would at 15. Or to put it another way, with the same impact you'd feel as if you fell three stories.  Have a death wish?  At 60 miles per hour it's sixteen times the impact - just not worth the risk to you and your loved ones. 
 
A properly worn safety belt keeps that second collision - the human collision - from happening!