Too many Alberta parents take their children out of booster seats too early, says a child safety group.

Provincial law stipulates the child must be in a car seat until they are six years old or more than 40 lbs (18 kg). Alberta doesn't have a law specifically regarding booster seats, but recommends children should remain in a booster until they are nine years old or more than 80 lbs (36 kg).

Safe Kids Canada advocates children riding in car seats until they are 4' 9" (145 cm), regardless of age or weight.

The hard part is getting those older children to sit in boosters, said Dr. Angelo Mikrogianakis at the Alberta Children's Hospital.

"They don't want to sit in the car seat. They want to be like their big brother or big sister or mom and dad and sit in the regular seat. This is a time where for parents we would say safety is non-negotiable. It's important for them to make it a rule."

Regular seatbelts can slide up on shorter children, resulting in serious injuries in a crash, he said.

"God forbid if anything unfortunate happens, if there's any sort of accident or sudden stop, the seat belt puts pressures on areas where kids can suffer internal injuries."

New research from Safe Kids Canada estimates only 30 per cent of children who should be using a booster seat actually do when they are travelling in vehicles.