Most parents know to buckle their children into a booster seat in their own car but they don't always require them to use one in someone else's car.
That's according to a new study in this week's Journal Pediatrics.
The research found that more than 30 percent of parents don't enforce the same rules when their kids ride in a different car.
Most states require children to use a booster seat up to the age of eight.
National recommendations encourage booster seats be used until a child grows to 57 inches, which is the average height of an 11-year-old, according to the study.
Copyright 2012 KPHO. All rights reserved. CBS News contributed to this report.