Using in-depth investigations to identify transportation safety issues for wheelchair-seated occupants of motor vehicles

Abstract 

In-depth investigations of motor-vehicle crashes involve detailed inspection, measurement, and photodocumentation of vehicle exterior and interior damage, evidence of belt-restraint use, and evidence of occupant contacts with the vehicle interior. Results of in-depth investigations thereby provide the most objective way to identify current and emerging injury problems and issues in occupant safety and crash protection, and provide important feedback on the real-world performance of the latest restraint-system and vehicle crashworthiness technologies. To provide an objective understanding of real-world transportation safety issues for wheelchair-seated travelers, the University of Michigan Transportation Research Institute (UMTRI) has been conducting and assembling data from in-depth investigations of motor-vehicle crashes and non-crash adverse moving-vehicle incidents, such as emergency vehicle braking, turning, and swerving, in which there was at least one vehicle occupant sitting in a wheelchair. The results of 39 investigations involving 42 wheelchair-seated occupants have been assembled and entered into a wheelchair-occupant crash/injury database. In addition, a biomechanical analysis of each case has been performed to identify key safety issues for wheelchair-seated travelers.

The wheelchairs of 34 of the 42 occupants who were seated in wheelchairs while traveling in motor vehicles were effectively secured by either a four-point, strap-type tiedown system or a docking securement device, and all but one of these properly secured wheelchairs remained in place during the crash or non-collision event. However, 30 of the 42 occupants were improperly restrained, either because of non-use or incomplete use of available belt restraints, or because the belt restraints were improperly positioned on the occupant's body. Twenty-six of the 42 occupants sustained significant injuries and 10 of these occupants died as a direct result of injuries sustained, or from complications resulting from those injuries. These findings, when combined with the analyses of the individual cases, point to a need for better driver and caregiver education and training on how to properly secure wheelchairs and position belt restraints on wheelchair-seated passengers. They also point to a need for improved restraint systems used by wheelchair-seated drivers, and a need for wheelchair designs that facilitate the proper use and positioning of vehicle-anchored belt restraints.

Keywords: Wheelchair-seated occupant, Occupant restraint, Belt restraint, Wheelchair tiedown, Wheelchair securement, Occupant protection, In-depth crash investigation