The hassle factor of car seats is well known to parents. However, the costs of not using them are immense. A 1997 National Highway Traffic Safety Administration (NHTSA) report found that 56,700 children were seriously injured in a car crash that year despite wearing a seat belt.
Many parents mistakenly believe that once a child is five, a seat belt is sufficient to protect their child. The NHTSA report found that 91% of parents use car seats for children age four and under, but the number who used booster seats drops to 5% after age five. "Children under eight sink too low in the seat to use only a seat belt," explained Art Kinsman, Director of Government Affairs for AAA Southern New England. "Although a seat belt is preferable to no restraint at all, a booster seat acts as a critical belt positioning device.
A booster seat ensures that the lap and shoulder belts, designed for adults, fit correctly on a child. A booster seat prevents serious abdominal and neck injuries that can result in a crash when a child is only restrained with a seat belt."
This information provided by the Group Insurance Commission.