Drawings Courtesy of NHTSA

Children should use a booster seat when they are 4–8 Years Old or Older, 40 lbs. to 80–100 lbs., and less than 4 feet 9 inches (57 inches). There are 3 types of booster seats, backless, high back and shield backless. The shield backless is no longer used. This is due to a nearly eight fold increase in serious injury when riding in these seats. Based on studies of the American Academy of Pediatrics, crash tests showed that dummies weighing less than 40 pounds were likely to be ejected, and that babies had greater trauma to their upper body, abdomen, and head.