This paper summarizes work conducted by the authors and other researchers to study the effectiveness of various child safety seat systems in restraining children during crashes with significant lateral acceleration. The Federal Motor Vehicle Safety Standards (FMVSS) currently only require dynamic testing of child safety seats in simulated frontal crashes. This has resulted in the child safety seat industry focusing almost solely on frontal crash performance. However, the National Highway Safety Administration (NHTSA) has requested comment on side impact testing for child safety seats by issuing an Advanced Notice of Proposed Rule Making (ANPRM), 49 CFR Part 571, Docket No. 02-12151. Enactment of a rule change to require side impact testing should result in greater considerations for lateral impact scenarios. Statistics indicate that a large percentage of injuries occur to children while restrained in vehicles subjected to side impacts. Research has found that the lateral crash protection provided by Child Safety Seats (CSS) can vary widely due to design differences. CSSs with dual shoulder straps typically only accommodate children weighing up to 40 pounds and from 40 to 43 inches in height. Generally, parents or caregivers who are aware of the need to use a restraint system other than just the adult belt for children who have outgrown the traditional CSSs, are often only aware of the belt positioning booster (BPB) or the Booster- With-Shields (BWS) used in conjunction with the adult seat belt. However, testing with adult cadaver and Anthropometric Test Dummy (ATD) has found that occupants restrained by a lap and shoulder belt can readily slip out of the shoulder belt during lateral crashes when the crash occurs on the side opposite the shoulder restrained by the shoulder belt (far side impact). While this testing also indicated that the occupant’s kinetic energy was significantly reduced by the restraint system, in spite of the occupant slipping the shoulder belt, researchers have suggested that such a reduction in kinetic energy may not occur with children using adult belts due to their smaller size and greater torso flexibility, thus subjecting them to greater risk of injury. Simulated side impact crash testing conducted by various organizations and the authors demonstrates the variation in child safety seat performance in lateral crashes and the effects of design differences. It also demonstrates the lack of lateral restraint provided to children by either the adult lap and shoulder belt with a BPB or with a BWS CSS in “far side” lateral crashes. The information provided in this paper will have application to all modes of transportation of children including automotive, amusement, rail, and air.
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