The National Highway Traffic Safety Administration recommends that all children ages 12 and under sit in the rear seat of a moving vehicle and use a height/weight appropriate child safety seat or booster seat. Booster seats elevate children to improve the fit of vehicles’ seat belts, which are designed for adults. Premature graduation to seat belts is common among older children.

Research shows that among children 4-7 years old, 26% are using belts only, rather than booster seats. An additional 12% were unrestrained. The height/weight ranges for child restraint and booster seat use recommendations were developed decades ago. The average sizes of children at various ages have increased since that time.

The Centers for Disease Control and Prevention (CDC) asked Westat to conduct a study to update the height recommendation for promoting children from using booster seats to using adult seat belts while traveling.

Because the back seat is the recommended seating location for children 12 and under, Westat will collect seat belt fit measurements among children seated in the rear passenger seat of a number of different vehicles.

Anthropometric (body size) measurements related to seat belt fit will be collected from children ranging from 6 to 13 years old.

The measurements will include the child’s overall height, seated height, and weight. In addition, age, sex, race/ethnicity, and calculated Body Mass Index (BMI) will be recorded.  Vehicle information, such as seat cushion size and angle that could affect seat belt fit, also will be collected from various passenger vehicles.

The study will enable CDC to identify the height and age range at which a child will properly fit in the vehicle’s seat belt system.

CDC can then target efforts to educate the public as to when it is safe to promote a child from a booster seat to the vehicle seat belt.