Effects of Adjacent Vehicle Seat Positions on Child Restraint System (CRS) Performance in Far-Side Impacts

Many vehicles allow consumers to adapt the vehicle environment to their families’ needs by folding or removing one or more rear row seats. It is currently unclear how different seat configurations affect child restraint systems (CRS) installed in adjacent seats. The objective is to quantify CRS performance in far-side impacts when the seating position adjacent to the CRS is in its normal upright position, folded in half, or removed. Twelve tests were conducted. Second row seats from a recent model year minivan were obtained, including full size captain’s chairs from the outboard positions and narrow seats from the center position. Rear-facing (RF) and forward-facing (FF) CRS were installed one at a time in either the outboard or center position. The seating position adjacent to the CRS was set in either the standard upright position, folded in half, or removed. Far-side impacts were conducted at 10° anterior of pure lateral at 24.8 ± 0.2 g. The Q3s ATD was used for all tests. CRS installed with the adjacent seat removed tended to have the most lateral displacement but lowest HIC36, resultant chest acceleration, and neck loads. Adjacent upright vehicle seats limited the motion of the CRS bases with mid-level level injury metrics. Adjacent folded vehicle seats reduced CRS displacement the most but resulted in higher injury metrics in the head, neck, and chest. When the RF CRS was installed in the narrow center seat with the adjacent (outboard) seat removed, the lower anchor connector of the RF CRS released from the anchor during the impact. This likely occurred due to the narrow seat cushion combined with the shape of the lower anchor hardware. With the exception of this extreme failure, the RF CRS tended to produce lower injury metrics compared to the FF CRS for all corresponding conditions.