The U.S. Transportation Department said Wednesday it is revamping a consumer ratings system for child safety seats to help parents and caregivers make the best choice for their kids.

The new approach will use a five-star rating system, based on the seats' ability to secure a child and the ease with which the seats are installed. It will also consider the seats' labeling and instruction manuals.

"We believe that the new star system will help simplify one of parents' most important decisions: choosing the best safety seat that will protect their children," Transportation Secretary Mary Peters said during a news conference at an Arlington, Va., fire station.

Many parents can attest to the frequent frustration found in securing a car seat or making sure their child is strapped in. The National Highway Traffic Safety Administration said seven in 10 child safety seats are either the wrong size or misused, reducing their ability to protect kids in a crash.

"If one of these things is difficult to use, even if someone buys one, they may not be willing to switch them among cars … because they remember what a pain they were to install," said Adrian Lund, president of the Insurance Institute for Highway Safety.

"If we get seats that are easier to install, then it's more likely that people will use them."

When used properly, the seats are very effective. NHTSA estimates that child restraint systems reduce fatal injuries by 71 per cent for infants and 54 per cent for toddlers in passenger cars and by nearly 60 per cent for infants and toddlers in sport utility vehicles, pickup trucks and vans.

Transport Canada estimates when properly used, car seats have been found to reduce deaths by 90 per cent in the event of a collision.

Transportation officials stressed that the new ratings system does not assess how effective a seat is in protecting a child in a crash. All child seats must comply with federal safety standards to protect children in a car accident.

The new system, which assigns an overall rating of up to five stars, replaces an older ratings program which used letter grades. The five-star rating system is also used in NHTSA's consumer crash test program for new cars and trucks.