2003 GMC Sierra 1500 Pickup Owner's Manual - Page 18

In most states and in all Canadian provinces, the law says to wear safety belts. Here's why: They work. You never know if you'll be in a crash. If you do have a crash, you don't know if it will be a bad one. Why Safety Belts Work When you ride in or on anything, you go as fast as it goes. A few crashes are mild, and some crashes can be so serious that even buckled up, a person wouldn't survive. But most crashes are in between. In many of them, people who buckle up can survive and sometimes walk away. Without belts they could have been badly hurt or killed. After more than 30 years of safety belts in vehicles, the facts are clear. In most crashes buckling up does matter...a lot! Take the simplest vehicle. Suppose it's just a seat on wheels.