Chevrolet 2003 Astro Owner's Manual page 38

The lap part of the belt should be worn low and snug on
the hips, just touching the thighs. In a crash, this applies
force to the pelvic bones. And you'd be less likely to slide
under the lap belt. If you slid under it, the belt would apply
force at your abdomen. Phis could cause serious or
even fatal injuries. The shoulder belt should go over the
shoulder and across the chest. These parts of the body
are best able to take belt restraining forces.
The safety belt locks if there's a sudden stop or a crash.
is too loose. In a crash, you would move
forward too much, which could increase injury.
The shoulder belt should fit against your body.
To unlatch the belt, just push the button on the buckle.
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