Child car seats have proven to reduce injuries in a crash and even though all states have child-restraint laws for younger children, not all states extend the coverage for older children. A new study by the Insurance Institute for Highway Safety (IIHS) found that by expanding the child restraint laws to cover 7- and 8-year-olds, more children will be seated in the back seat, the use of booster seats will increase, and crash injuries will be reduced.

Researchers looked at state crash data to compare injury rates and restraint use, as well as the seating position for children aged 4 to 8 years old before and after five states increased their laws to require booster seats for children up to age 7. The states include Missouri, North Carolina, Pennsylvania, and Wisconsin, which increased their coverage to include children up to age 7, and Wyoming, which increased their requirement to age 8. The Institute found that the expanded laws were associated with a 5-percent decrease in injuries and a 17-percent decrease in deaths and severe injuries. In addition, the children covered by these new laws were three times more likely to be seated in appropriate child restraints including boosters and 6-percent more kids were seated in the back seat after the laws were expanded.

Currently, 29 states, plus the District of Columbia, have child restraint laws that cover children up to age 7. Wyoming and Tennessee’s laws extend to age 8.

Earlier studies have shown that children ages 4-8 who are seated in boosters are 45 percent less likely to be injured in a crash compared to children using just seat belts alone. However, a 2009 observational study by the National Highway Traffic Safety Administration (NHTSA) found that only 55 percent of 4-7 year olds were in an appropriate restraint.

Booster seats help children position themselves better with the vehicle’s seat belt. By using only the vehicle’s belts, children are at risk of a host of injuries to their hips, pelvis, and spine.

Consumer Reports, the government, child safety organizations, and the American Academy of Pediatrics stress the importance of keeping your child in the proper restraint until they are tall enough for the vehicle belts to fit correctly (usually when they are around 4’9” tall) and that all children age 13 and younger should sit in the backseat.

For more on finding the right booster seat for your child, see IIHS’ list of the best-fitting booster seats. Also, check out Consumer Reports ratings of booster seats.