What has been done done to improve injury prevention for wheelchair-seated vehicle users?
There have been many improvements in wheelchair transportation safety in the past three decades. The federal safety standards administered by the National Highway Traffic Safety Administration (NHTSA) of the US Department of Transportation generally only apply to the original vehicle manufacturer. In addition, most passenger vehicles modified for use by wheelchair users are exempt from federal safety requirements to allow greater independence. Because wheelchairs are considered medical devices regulated by the Federal Drug Administration, NHTSA does not have standards for addressing wheelchairs used as vehicle seating. However, several standards organizations have developed voluntary standards with the intent of providing people using wheelchairs as seating with a similar level of safety as those using standard vehicle seats and equipment.
In the 1990s, the Society of Automotive Engineers (SAE’s) Adaptive Devices Subcommittee formed a Restraints Task Force. In 1996, the task force published SAE Recommended Practice J2249, Wheelchair Tiedowns and Occupant Restraint Systems for Use in Motor Vehicleses, which establishes design and performance requirements for wheelchair tiedown and occupant restraint systems (WTORS) that are used by wheelchair-seated occupants.
As SAE J2249 was issued, and crash-tested WTORS became available, the next barrier to achieving wheelchair transportation safety was the wheelchair. No wheelchairs had been designed and tested for use as a seats in motor-vehicles. In addition, some wheelchair manufacturers added labels such as “Not for use in motor vehicles” in an attempt to defray liability in case of a crash. Given that some people are unable to transfer from their wheelchairs for travel, addressing wheelchair crashworthiness became the next priority.
In 1995, the Wheelchair Standards Subcommittee of ANSI/RESNA formed a new working group to develop a voluntary wheelchair standard that addresses design and performance issues of wheelchairs that would allow safer seating in motor vehicles. ANSI (American National Standards Institute) is a well recognized standards-setting organization in the U.S. ANSI also serves as the U.S. representative on committees of the International Standards Organization (ISO), which sets technical standards on a world-wide scale. Within the U.S., ANSI has assigned standards development authority for wheelchairs and related equipment to the Rehabilitation Engineering and Assistive Technology Society of North America (RESNA).
The results of efforts by the ANSI/RESNA Standards Committee on Wheelchair Transportation (SOWHAT) is Section 19 ANSI/RESNA WC/Volume 1 Wheelchairs for Use in Motor Vehicles, or simply WC19, which was completed and approved in May 2000. The two most important requirements are:
- that a wheelchair provide four easily accessible securement points (or tiedown points) with very specific geometry (Sections 4.5 – 4.8), and
- that the wheelchair is successfully crash tested at 30 mph when secured by a four-point strap-type tiedown, and loaded with an appropriate size crash test dummy representing the intended size and mass of wheelchair user (Section 5.3 and Annex A).
Wheelchairs that comply with this standard are referred to as WC19-compliant wheelchairs, or wheelchairs with the transit option.
RESNA’s SOWHAT working group became a RESNA committee and is now referred to as RESNA COWHAT. One COWHAT’s most important contributions was publishing Volume 4 of the ANSI/RESNA Wheelchair Standards: Wheelchairs and Transportation. Volume 4 brings all standards and supporting documents related to wheelchair transportation safety into one published document. Volume 4 was published in December 2012, revised in 2017 and contains the following standards:
- WC18 – a revised and updated version of SAE J2249, Wheelchair Tiedown and Occupant Restraint Systems for Use in Motor Vehicles
- WC19, Wheelchairs for Use as Seats in Motor Vehicles
- WC20, Wheelchair Seating Systems for Use in Motor Vehicles
- WC10, Wheelchair Containment and Occupant Retention Systems for Use in Large Accessible Transit Vehicles: Systems for Rear-Facing Passengers
It also contains documents that provide specifications and engineering drawings for equipment used in the test methods of these standards, including the surrogate wheelchair used for WTORS testing, the surrogate wheelchair tiedown and occupant restraint (SWTORS) used for wheelchair testing, and the surrogate wheelchair frame (SWCF) used for seating system testing. Find the drawing packages here.
For more information on products that comply with these U.S. standards, and with comparable ISO standards, look on the compliant products page of this website. For more information on manufacturers that have participated in the development of industry safety standards or market products that conform to the standards requirements see FAQ: Question A-4.