Fatal side impact crash scenarios for rear seat and seat belt–restrained occupants from vulnerable populations

Abstract

Objective: Previous studies have revealed vulnerability of school-age children and older adults in rear seats in motor vehicle crashes. Detailed information about crashes in which these fatalities occur could help improve vehicle and restraint design.Methods: Police accident reports were obtained for crashes from the Fatality Analysis Reporting System data set. Inclusion criteria were crashes in which there was at least one fatally injured restrained rear seat occupant between the ages of 6 and 12 or 55 and older in a passenger vehicle no older than 10 years at the time of the crash. Reports were reviewed for key crash data. Side impacts were selected for analysis.Results: Thirty-nine side impact crashes met the inclusion criteria, resulting in 46 fatalities of interest. Far-side or nondirect impact cases outnumbered near-side cases by 15–11 for juvenile occupants. Sixty-one percent of occupants were in vehicles with side airbags (SABs), all of which deployed for their position, although torso SABs were only present in 3 cases. Head injuries were present in all juvenile cases with injury data available and older occupants suffered equally from head and torso injuries. Impacts with pickup trucks and heavy trucks made up 31 and 22% of all cases, respectively. Three-quarters of cases were judged as survivable for the fatally injured occupant(s), and 5 of 7 cases deemed unsurvivable involved juvenile decedents. Further, of those deemed survivable, two-thirds had damage comparable in magnitude with the same vehicles in consumer information crash tests, evaluated by photo comparison.Conclusions: Older adults suffered thoracic injuries at a higher rate than older children—who suffered predominately head injuries—and most vehicles did not have torso SABs installed, which could have mitigated thoracic injuries. Side impacts in which younger occupants were killed were more severe than impacts that resulted in the death of an older occupant; however, vehicle damage and intrusion in many fatal impacts for both age cohorts appeared similar to that of consumer information testing. Large pickups and heavy vehicles were the striking vehicle in over half of all fatalities; vehicle designs and crash tests should continue to take this into consideration. This research highlights the need for continued work as the automotive safety community seeks to eliminate fatalities in motor vehicle crashes.