While the state law requiring child safety restraints covers children only up to age 7, size and positioning of children in vehicles will make a difference in preventing death or serious injury in crashes, said Lahaina police Capt. Charles Hirata.

"Despite the law, people should always go with best practice," said Hirata, a National Highway Traffic Safety Administration certified child passenger safety instructor. "Best practice includes using proper restraints until the child is big enough for adult seat belts.

"I always tell parents, 'If it were my child, I would have him in a proper restraint or a booster seat until he fits behind the seat belt properly.' "

Under state law, child car seats are required for children under age 4. A law that took effect Jan. 1 requires children from ages 4 to 7 to be restrained in either car seats or booster seats.

Exempted from the booster seat law are children who are taller than 4-feet-9 or who weigh 80 pounds or more.

For children who are older than age 7 but on the smaller side, "it becomes a parental decision," said Lt. Bobby Hill, commander of the police Traffic Section.

He said children are generally safer in the back seat of a vehicle.

"My daughter's still in the back seat at age 10," Hill said. "We do know, statistically, that kids do better in the back seat — centered. The right front is the death seat. It has the most injuries."

Hirata said there is increased interest in booster seats generated by the June 3 collision on Honoapi'ilani Highway that killed 8-year-old Will Smith of San Antonio, Texas.

He was a passenger in a car driven by his mother that was struck by an oncoming car when its driver lost control of the vehicle, veered off the roadway, then went into the opposite lane of traffic near Ukumehame Wayside Park, police said.

While the boy was wearing a seat belt, his smaller size — 4-feet-1 and 60 pounds — made him "not a good fit" for the seat belt, according to Dr. Anthony Manoukian, Maui County coroner's physician who performed the autopsy on the child.

Nationwide, children secured in ill-fitting seat belts could be ejected or suffer serious injuries in crashes, Hirata said.

"Sometimes they're called the forgotten children because they graduate from child seats but they're too small for seat belts," he said.

Using a booster seat will change the positioning of a child to properly fit in a seat belt, Hirata said. A seat belt should be tight around the hips, not over the belly; a shoulder strap should run across the chest and shoulder, not across the neck. He said it's recommended that seats not be reclined.

In addition to recommending booster seats for some children, the National Highway Traffic Safety Administration recommends that children under age 13 ride in the back seat, which is usually safer, and use lap and shoulder belts, Hirata said. He said the safest position is usually in the center portion of the back seat, especially in a front-impact collision.

"Anybody can benefit from riding in the back seat," Hirata said. "The closer you are to the crash point, the more energy is going to be transmitted."