Booster seats are designed to lift kids aged 4 to 8 years old, so that seatbelts fit them properly. Fortunately the ones made now are doing a better job of this.
"There was a 5 percent decrease in the per capita rate of injury for children in crashes," said IIHS Senior Vice President Anne McCartt. "There was a 17 percent decrease in the rate of serious and fatal injuries."
IIHS says the main reason booster seats are doing a better job today is the fit of the seat belt. If the belt is fitted properly then your child is safer. It is not booster seats, but seat belts, that restrain kids in crashes.
"The lap belt should lie flat across the thighs, not riding up on the abdomen," said McCartt. "The shoulder belt should fit snuggly across the center of the shoulder, not sliding off the shoulder or riding up on the neck."
Unfortunately more than half of the seats don't work as they should and six seats tested were not recommended because they failed to properly use the lap or shoulder belt.
And you don't have to spend an arm and a leg to protect your child's arms and legs.
"You can get a 'Best Bet for less than $15," said McCartt. "You can't tell by looking at a seat, you can't tell by the price of the seat. Really you need to look at our ratings to try to take the guess work out of choosing a booster that will predictably and consistently do a good job."