Zack Zindler, 9, of Bethesda, Md., didn't like that idea. "Bad," was his one-word reaction to the notion that he could still be sitting in a booster.
"He thought it was very cool when he got to the seatbelt," mom Jamie Zindler said. "Once their friends get out [of the booster seat], they don't want to do it."
Zindler said she moved him out of the booster in the past few months, based on previous recommendations that the seats were for children through age 8.
Any parent knows continued booster-seat use could be a hard sell. "Traffic crashes are the largest killer of children, period," NHTSA's Strickland said. "Just because your child may not be happy about having to be in a booster seat a little bit longer, I think you would rather have to deal with that situation than having your child sustain an injury that could have been avoided if they were in a properly fitted restraint."
Durbin of Children's Hospital, who has treated many young car-crash victims, said children have become expert negotiators. But he advises families that "safety really should not be negotiable."
Forty-seven states and the District of Columbia require booster-seat use for older children but the age limits vary widely. Tennessee and Wyoming have the strictest laws, requiring booster seats through age 8. A dozen states require their use only though age 5. There are no booster seat requirements in Arizona, Florida and South Dakota.
Strickland and Durbin agree it can be confusing for parents when state laws don't match up with government and pediatrician recommendations. They said they hope the new recommendations convince state governments to take another look at their car-seat laws.
"There's no question in my mind that consistent following of these recommendations will help parents ensure that their children are as well protected as they can possibly be in the event of a crash," Durbin said.
Amy Graham, the mother of 6- and 3-year-old boys, said she has no issue with the new recommendations. "If there's evidence that it improves safety, she said, "it makes sense."
Here at the new car-seat recommendations from the American Academy of Pediatrics and the National Highway Traffic Safety Administration:
Rear-Facing Seat: Use from birth to age 2, or until the child reaches the maximum height and weight for their seat.
Forward-Facing Seat with Harness: Use as long as possible, until child is within the height and weight restriction for the seat.
Booster seat with car seatbelt: Use until the child is 4-feet 9-inches tall, possibly up to age 12.