GMC 2004 Sierra - Manual (Page 18)

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!
Why Safety Belts Work
When you ride in or on anything, you go as fast as
it goes.
Take the simplest vehicle. Suppose it’s just a seat on
wheels.
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