Revisiting Rear Seat Safety: Field Evaluations of Relative Injury Risk Across Seating Positions and the Integration of Advanced Rear Seat Belt Systems.

Despite advances in automotive crash avoidance, occupant restraint systems remain crucial in protecting the motoring public. Following decades of improvement in occupant protection, including the development of features such as frontal airbags, collapsable steering columns, and seat belt pretensioners and load limiters for the front seat, the safety of rear seat occupants has recently undergone scrutiny. Studies evaluating rear seat occupant injury risk via field crash data have reported findings of reduced relative safety in the rear seating positions and alluded to rear seat advanced restraints, such as pretensioners and load limiters, as a potential solution. While the pursuit of certain novel technologies has historically improved automotive occupant outcomes, evaluation of these new systems in both controlled laboratory environments and field crashes is necessary to understand potential positive and negative effects of widespread introduction. This study expanded upon prior field data analyses of relative front and rear seat occupant injury risk in frontal crashes in a manner that controlled for crash exposure. Occupant injury risk was also compared across vehicles equipped with and without advanced seat belts (load limiters and pretensioners) in the rear seat. Results indicated that trends in relative rear versus front seat occupant injury risk were driven by evolution of front seat occupant protection systems. Risk of serious injury to rear seat occupants has historically been and remains low, and current field data do not demonstrate a meaningful reduction in rear seat occupant injury or fatality risk attributable to advanced seat belts. Additionally, the relatively low number of crashes involving serious injury or fatality for rear seated occupants in vehicles equipped with these systems underscores the need for additional data to fully evaluate their effectiveness in real-world crashes.