Children's car seat restraints: when top-tether straps are ignored, are these restraints safe?

Children's car seat restraints are impact sled-tested to evaluate their safety qualities. To determine whether these restraints can protect the child, it is necessary to test in two different ways those restraints that require a top-tether strap: (1) installed in accordance with the manufacturer's directions; and (2) installed in the manner they are actually used. In this study the five children's car seat restraints top-rated by a leading consumer organization were impact sled-tested with a top-tether strap in use. They were then tested without the top-tether strap--the way such restraints are often being used as indicated by an Insurance Institute for Highway Safety survey. In addition, two leading restraints not requiring a top-tether strap, but secured by the auto lap belt, were tested. This study shows that the five top-tethered restraints, when installed with top-tether and lap belt, and the two restraints not requiring a top-tether give good protection in a frontal crash. It also shows that, with one possible exception, the five restraints that require a top-tether strap do not provide adequate protection if the top-tether strap is not used.