Wheelchair Transportation Safety
Frequently Asked Questions

The answers to FAQs provided in this document are intended for wheelchair users, parents, practitioners, clinicians and medical personnel, physical and occupational therapists, transit providers, school-bus transportation companies and personnel, transportation systems administrators, and the manufacturers of wheelchairs, wheelchair seating systems, and after-market wheelchair tiedown and occupant restraint systems who are concerned with transportation safety for children and adults who remain seated in their wheelchair when traveling in a motor vehicle. These answers have been developed in response to questions arising from the development of new voluntary standards for designing and testing:

1. devices used for wheelchair securement (tiedown) and belt-type occupant restraints,
2. wheelchairs intended for use as seats in motor vehicles, and
3. wheelchair seating systems intended for occupancy in motor vehicles.

Some questions and answers apply to transportation safety in general. Others are related to specific issues that have been raised or for which there has been misunderstanding about what the standards say or mean.

The questions and answers have been arranged into the following four groups:

1. General (general transport safety principles and issues)
2. Wheelchair Tiedown and Occupant Restraint Systems (WTORS- SAE J2249 Recommended Practice, ISO 10542 standards)
3. Transport Wheelchairs (ANSI/RESNA WC19 and ISO 7176-19 standards)
4. Wheelchair Seating (ISO-16840-4 standard)

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Note: If you do not find an answer to your question below, please send your question to:

Larry Schneider at lws@umich.edu

or

Douglas Hobson at dhobson@pitt.edu

We will do our best to respond. If appropriate, your question and our response will be added to this FAQ forum without identifying you.

A-1: What are the main safety concerns and issues for someone seated in a wheelchair while in a motor vehicle?

Answer:
First, let's think about some of the primary occupant-protection features that are used in family vehicles, i.e. cars, vans and SUVs. The seats are firmly anchored to the vehicle floor, and they are designed without rigid sharp edges that could cause injury. The seats are also designed and dynamically tested to ensure that they will provide effective support for the occupant. A properly designed three-point belt restraint will provide effective upper and lower torso restraint by applying forces to the skeletal structures of the body. The vehicle seat and belt restraint system work together to prevent occupant ejection and minimize the potential for occupant contact with the vehicle interior, which causes injury.

Since the early 1990s, all passenger vehicles have been equipped with airbag restraints that deploy rapidly in frontal crashes to provide additional protection to the heads, faces, necks, and chests of front-seat occupants. In this way, the seat and occupant restraints (belts plus airbags) work with the vehicle structure's ability to withstand a crash, to form a safety system that allows the occupant to “ride-down” or gradually absorb the vehicle deceleration. This would reduce contact with vehicle interior structures, thereby minimizing the possibility of serious injury.

In contrast to the seats come standard as a part of the vehicle, most wheelchairs have not been designed for use as seats in motor vehicles. The wheelchair frames and seats are generally not strong enough to withstand the thousands of pounds of impact forces that can result under crash conditions. For many wheelchairs, it is difficult to find suitable places on the wheelchair frame for attaching wheelchair tiedowns. Even when it is possible to find usable attachment points, it is unlikely that those places are strong enough to hold up under a significant crash. In many cases, tiedown straps are attached to the most accessible places on the wheelchair, which are often the weakest places. For example, if tiedown straps are attached to footrests or armrests that are detachable, the wheelchair will not withstand even a relatively minor crash event. If the wheelchair is not effectively secured, the mass of the wheelchair, which can exceed 250 lb, will add to the belt-restraint forces on the occupant’s body in a crash situation.

In addition, for effective occupant protection, belt restraints must fit over the pelvis and shoulders. However, the design of most wheelchairs makes positioning of vehicle-anchored restraints difficult and often prevents a good fit of the occupant restraint due to the location of arm rests, push wheels and seat frame panels.

Injury biomechanics research and crash investigation data show that the orientation of the occupant in the vehicle relative to the impact direction also has significant safety implications. In many cases, wheelchair occupants are placed facing sideways in the vehicle, since this is easiest for getting wheelchair occupants in and out of the vehicle. When facing sideways, the occupants are in the least-safe orientation for enduring a frontal crash, which is the direction of impact that accounts for in excess of 50% of injury accidents. While occupants who face rearward can be provided with effective frontal impact protection if they are backed closed up to a high-backed padded structure, this is difficult to achieve in practice and is often not acceptable in many transportation situations. In the absence of properly designed back and head support structures, all occupied wheelchairs should be oriented facing forward during transit in a vehicle.

Trays and tray-mounted accessories, such as laptop computers or communication devices, are rarely fixed to wheelchairs in a manner necessary to minimize the chance of injury. It is therefore recommended that these devices be stowed elsewhere during transit. If they must remain on the wheelchair, they should be attached with stronger mechanisms or tethers to prevent them from breaking loose in a crash.

Clearly, the years of automotive crash safety research that has made our motor vehicles safer over time is only now being extended to people who use motor vehicle transportation while seated in their wheelchairs. In most cases, transfer to the vehicle seat will offer the highest level of occupant protection since the occupant can then use seats and restraint systems that comply with federal motor vehicle safety standards, and other consumer-rating tests. Those wheelchair users who remain seated in their wheelchairs while traveling in motor vehicles will be at increased risk of injury in a collision for the reasons outlined above, unless some additional steps are taken to implement the proven safety features.

For more information on the biomechanics of injury prevention and wheelchair transport safety see:

WTORS-RP-J2249-Application Guidelines (June, 1999)

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A-2: What steps are being taken to improve injury prevention for wheelchair-seated vehicle users?

Answer:
Because the federal safety standards administered by the National Highway Traffic Safety Administration (NHTSA) generally only apply to the original vehicle manufacturer, after-market vehicle add-on equipment used in the transportation of wheelchair-seated drivers is not regulated by these standards. Until recently, this equipment had not been designed to hold up under the forces that are typically generated by the wheelchair and occupant in crash situations, and hadn't been designed with basic principles of occupant protection in mind. As indicated in the answer to Question A-1, the level of occupant safety and protection available to wheelchair-seated occupants has been far below that available to able-bodied travelers. Able-bodied travelers use seating and restraint systems that are regulated by federal motor vehicle safety standards and numerous consumer ratings tests.

In recognition of this problem and the fact that government standards were not going to be developed for these after-market vehicle products in the foreseeable future, the Restraints Task Force was formed within the Society of Automotive Engineers (SAE’s) Adaptive Devices Subcommittee. The purpose of the task force was to establish a Recommended Practice (RP) of design and performance requirements for wheelchair tiedown and occupant restraint systems (WTORS) that are used by wheelchair-seated occupants. SAE RP J2249 Wheelchair Tiedowns and Occupant Restraint Systems for Use in Motor Vehicles was completed and published in 1996. Today there are many WTORS on the market that comply with the requirements of this RP.

As the SAE Restraints Task Group was nearing completion of SAE J2249, and as WTORS manufacturers began to market equipment that complies with this Recommended Practice, it became obvious that the primary remaining obstacle to providing safe transportation for wheelchair-seated occupants is the wheelchair. Not only were wheelchairs not designed and tested for use as a seats in motor-vehicles, which is a use that is mandated by federal legislation, but many wheelchair manufacturers had begun labeling their wheelchairs with statements such as “Not for use in motor vehicles” or words to that effect. Clearly this is not a reasonable option for thousands of wheelchair users, and was being done by wheelchair manufacturers in an attempt to defray liability in the event that a wheelchair-seated occupant was injured in a motor-vehicle accident.

In response to this situation, in 1995 a new Working Group was formed under the Wheelchair Standards Subcommittee of ANSI/RESNA to develop a voluntary wheelchair standard that addresses design and performance issues of wheelchairs that will offer more suitable and 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. ANSI/RESNA WC19 is a fairly comprehensive standard that addresses many issues of wheelchair design and performance. To summarize, however, the two most important requirements are:

1. that a wheelchair provide four easily accessible securement points (or tiedown points) with very specific geometry (Sections 4.5 - 4.8), and
2. 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 anthropomorphic 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. (See FAQ: Question A-13 for information on how to purchase complete standard).

For more information on products that comply with these U.S. standards, and with comparable ISO standards, contact your local wheelchair supplier or wheelchair manufacturer. 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.

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A-3 What is the overall goal of the WC19 compliant wheelchair and WTORS standards?

Answer:
The overall goal of WC19 and of SAE J2249 is to provide the wheelchair user with the opportunity and the option to use equipment (i.e., a wheelchair seat, a wheelchair, a wheelchair securement system, and an occupant restraint) that is comparable in design and performance to seats and restraint systems available to able-bodied travelers in motor vehicles. It is not necessarily the goal of these standards to provide a comparable level of injury risk prevention for wheelchair occupants to that of the able-bodied population. Injury risk is a function of many biomechanical factors such as: body size, body condition and occupant age. When varying levels of disability are added to these factors, it is most likely that the wheelchair occupant will be at higher risk of injury then a person without a disability. It is also not the goal of WC19 to regulate or require the use of WC19-compliant wheelchairs in the real world. While there is little doubt that the use of WC19 wheelchairs, along with SAE-compliant WTORS and recommended transportation procedures, will increase the level of occupant safety and crash protection available to wheelchair users during transit, the decision to purchase and use a standards compliant wheelchair is at the discretion of the wheelchair user and other consumers.

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A-4 What is the basis for these WC19 wheelchair and WTORS standards?

Answer:
The requirements and provisions of WC19 and SAE J2249 are based on some fundamental principles of occupant protection. These include the following:

1. The most common cause of serious and fatal injuries is occupant contact with vehicle interior components, or with objects outside of the vehicle following or during ejection.
2. The majority of serious injury-producing crashes occur during frontal impact, or when the principal direction of vehicle deceleration is in the direction of vehicle travel, or toward the front of the vehicle.
3. Effective occupant protection requires effective occupant restraint by a belt-type restraint system that includes a lower-torso or pelvic/lap belt and an upper-torso shoulder belt or harness.
4. Restraint belts must be positioned so that the forces applied to the occupant in a crash are primarily to the skeletal structures of the shoulders and pelvis.
5. Effective occupant restraint requires that the vehicle seat is effectively secured in the vehicle seat and that it has sufficient strength to support the occupant in a seated posture during impact. These are necessary to prevent the mass of the seat from transferring to the occupant in a crash, and to enable the belt restraints to remain in their preferred locations on the pelvis and shoulders.

In addition to these fundamental principles of occupant crash protection, these standards are based on provisions, requirements, and methods in current federal safety standards, such as FMVSS 213 Child Restraint Systems and FMVSS 209 Seat Belt Assemblies. The standards are also based on a desire to minimize the costs involved in testing to the standards.

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A-5 Why is it important to secure my wheelchair if other vehicle occupants are not restrained?

Answer:
It has been proposed by some wheelchair users that their wheelchairs should not have to be secured in the vehicle when other able-bodied travelers are not using belt restraints. The primary flaw in this argument lies in the distinction between seat securement and occupant restraint. While it is true that occupants of some vehicles, such as transit buses and larger school buses, are not provided with belt-type restraints, or rarely use them if they are provided, it is not true that their seat is not anchored to the vehicle. Thus, the fact that occupants are not restrained does not support the position that wheelchairs should not be secured. In a crash situation, an unsecured wheelchair is an injury hazard to both the wheelchair user and other occupants of the vehicle, just as an unanchored seat would be a hazard. This is especially true for power wheelchairs that can weigh well in excess of 200 lb.

With regard to the issue of wheelchair-seated occupants and occupant restraint systems in the school bus environment, it is also important to recognize that able-bodied students in large school buses are provided frontal crash protection through "compartmentalization," which is achieved through the use of closely spaced, high-backed padded seats. Since the wheelchair-seated student is generally not provided with compartmentalization and may, in fact, be surrounded by other wheelchairs with rigid protruding components, it can easily be argued that there is a need for wheelchair-seated students to use belt-type occupant restraints to achieve a comparable level of crash protection as that available to the able-bodied student. Fortunately, FMVSS 222 now addresses the safety of the wheelchair-seated student by requiring forward-facing wheelchair stations equipped with four-point, strap-type tiedowns and three-point belt-type occupant restraint systems. (See FAQ: Question A-9 for more information on FMVSS 222)

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A-6 Why is it safer to travel in larger vehicles?

Answer:
The simple answer is that it is safer to travel in larger vehicles because larger vehicles tend not to be involved in higher-severity crashes. As previously noted, crash severity is typically measured as the change in speed that the vehicle experiences during an impact event. This change in speed is often referred to as the crash "delta V" and is a measure of the kinetic energy that generates the forces on the occupant that can result in injury. In fact, the energy that an occupant must deal with is proportional to delta V to the second power, or to delta V squared, so that the energy in a 30-mph delta-V crash is more than twice that of a 20-mph delta V crash (i.e., 900 is more than twice 400).

The delta V that a vehicle experiences in a crash is not only a function of how fast it is moving but it's also a function of the mass of the vehicle or object that it strikes. If two vehicles of equal mass impact head on, then both will experience essentially the same delta V, which will be close to the speed of each vehicle at the time of impact. However, when a large vehicle impacts with a smaller vehicle, the smaller vehicle will experience a greater delta V than the larger vehicle - i.e., the small vehicle may actually reverse direction during the impact whereas the larger vehicle will continue to move in the same direction at a somewhat lower speed. For these reasons of physics, and the mix of large and small vehicles on the roadways, the distributions of real-world crash severities for large vehicles is significantly different and lower from that of smaller passenger-size vehicles. For these reasons, it is generally considered safer to travel in larger vehicles. Using larger vehicles to transport heavier occupants and heavy wheelchairs is a good countermeasure to concerns about the disparity between WTORS strength and forces generated by higher wheelchair and occupant masses.

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A-7: Does WC19 apply to all mobility devices and motor vehicles?

Answer:
Yes. WC19 requires that wheelchairs be crash tested in frontal-impact conditions that are applicable to a passenger-size vehicle - i.e., 30 mph, 20 g. Therefore, wheelchairs that comply with WC19 can be considered suitable for occupancy in all types of motor vehicles. The standard also applies to all types of wheelchairs, as long as the wheelchair allows the wheelchair user to attain a seated position, as defined by a seatback angle of 30 degrees or less to the vertical and a seat angle of 30 degrees or less to the horizontal. If these conditions are met, any child or adult wheelchair that complies with the requirements of the standard can be labeled and marketed as a WC19 wheelchair, including manual wheelchairs, powered wheelchairs, scooters, strollers and tilt-in-space wheelchairs. For wheelchairs designed only for children under 22 kg (about six years old), additional requirements are being developed for wheelchair-anchored belt restraints that must be anchored to (i.e., integrated into) the wheelchair.

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A-8: If I have a specific disability will I be at greater risk?

Answer:
It is important to recognize that tolerance to injury in motor-vehicle crashes varies widely across the population. Thus, elderly people are more likely to be injured or killed in a crash than are young people, and females are often more susceptible to injury than are males. It is therefore likely that people with certain disabilities will sustain certain types of injuries more often in a crash than people without those disabilities. However, regardless of the variation in injury tolerance, all people are less likely to be injured if they are provided with effective and properly positioned belt restraints and supportive and properly secured seating.

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A-9: Where can I get information about the requirements for school buses related to wheelchair transport?

Answer:
The federal regulations governing the design and construction of yellow school buses are contained in Federal Motor Vehicle Safety Standard (FMVSS) 222. FMVSS 222 is administered by the National Highway Transportation Safety Administration (NHTSA). Section S5 of FMVSS-222 deals with transportation of wheelchair-seated students in school buses, and includes the following statements:

S5.4 Each school bus having one or more locations designed for carrying a person seated in a wheelchair shall comply with S5.4.1 through S5.4.4 at each such wheelchair location.

S5.4.1 Wheelchair securement anchorages. Each wheelchair location shall have not less than four wheelchair securement anchorages complying with S5.4.1 through S5.4.1.3.

S5.4.1.1 Each wheelchair securement anchorage shall have a wheelchair securement device complying with S5.4.3 attached to it.

S5.4.1.2 The wheelchair securement anchorages at each wheelchair location shall be situated so that:

1. a wheelchair can be secured in a forward-facing position.
2. the wheelchair can be secured by wheelchair securement devices at two locations in the front and two locations in the rear.
3. the front wheel of a three-wheeled wheelchair can be secured.

S5.4.1.3 Each wheelchair securement anchorage shall be capable of withstanding a force of 13,344 Newtons applied as specified in paragraphs (a) through (d) of this section. When more than one securement device shares a common anchorage, the anchorage shall be capable of withstanding a force of 13,344 Newtons multiplied by the number of securement devices sharing that anchorage.

1. The initial application force shall be applied at an angle of not less than 30 degrees, but not more than 60 degrees, measured from the horizontal. (see figure 4)
2. The horizontal projection of the force direction shall be within a horizontal arc of +45 degrees relative to a longitudinal line, which has its origin at the anchorage location and projects rearward for an anchorage whose wheelchair securement device is intended to secure the rear of the wheelchair. (see figure 4)
3. The force shall be applied at the onset rate of not more than 133,440 Newtons per second.
4. The 13,344 Newton force shall be attained in not more than 30 seconds, and shall be maintained for 10 seconds.

S5.4.2 Wheelchair securement devices. Each wheelchair securement device shall:

1. If incorporating webbing or a strap
   1. comply with the requirements for Type 1 safety belt systems in S4.3, S4.3, and S4.4(a) of FMVSS No. 209, Seat Belt Assemblies; and
   2. provide a means of adjustment to remove slack from the device.
2. If not incorporating webbing or a strap, limit movement of the wheelchair through either the equipment design or a means of adjustment.

S5.4.3 Wheelchair occupant restraint anchorages share S5.4.3.1 Each wheelchair location shall have:

1. not less than one anchorage for the upper end of the upper torso restraint; and
2. not less than two floor anchorages for wheelchair occupant pelvic and upper torso restraints.

S5.4.3.2 Each wheelchair occupant restraint floor anchorage shall be capable of withstanding a force of 13,344 Newtons applied as specified in paragraphs (a) through (d). When more than one wheelchair occupant restraint share a common anchorage, the anchorage shall be capable of withstanding a force of 13,344 Newtons multiplied by the number of occupant restraints sharing that anchorage.

1. The initial application force shall be applied at an angle of not less than 45 degrees nor more than 80 degrees, measured from the horizontal (see Figure 5).
2. The horizontal projection of the force direction shall be within a horizontal arc of +45 degrees relative to a longitudinal line, which has its origin at the anchorage and projects forward. (see Figure 5.)
3. The force shall be applied at an onset rate of not more than 133,440 Newtons per second.
4. The 13,344 Newton force shall be attained in not more than 30 seconds, and shall be maintained for 10 seconds.
5. When a wheelchair securement device and an occupant restraint share a common anchorage, including occupant restraint designs that attach the occupant restraint to the securement device or the wheelchair, the loads specified by

S5.4.1.3 and S5.4.3.2 shall be applied simultaneously, under the conditions specified in S54.3.2 (a) and (b). (see Figure 6.)

S5.4.3.3 Each anchorage for a wheelchair occupant upper torso restraint shall be capable of withstanding a force of 6,672 Newtons applied as specified in paragraphs (a) through (d).

1. The initial application force shall be applied at a vertical angle of not less than zero degrees, but not more than 40 degrees below a horizontal plane, which passes through the anchorage. (see Figure 7.)
2. The projection of the force direction onto the horizontal plane shall be between zero and 45 degrees as measured from a longitudinal line with its origin at the anchorage and projecting forward. (see Figure 7.)
3. The force shall be applied at the onset rate of not more than 66,720 Newtons per second.
4. The 6,672 Newton force shall be attained in not more than 30 seconds, and shall be maintained for 10 seconds.

S5.4.4 E Wheelchair occupant restraints

1. Each wheelchair location shall have wheelchair occupant pelvic and upper torso restraints attached to the anchorages required by S5.4.3.
2. Each wheelchair occupant restraint shall comply with the requirements for Type 2 safety belt systems in S4.2, S4.3, and S4.4 (b) of FMVSS No. 209, Seat Belt Assemblies.

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A-10: What does ADA say about wheelchair transport on public transit vehicles?

Answer:
The Americans with Disabilities Act (ADA), signed into law in 1990 by President George Bush Sr., does contain requirements specific to wheelchair access, location, and the strength of wheelchair tiedown devices. An excerpt from the ADA follows:

1192.23
(d) Securement devices

(1) Design load. Securement systems on vehicles with GVWRs of 30,000 pounds or above, and their attachments to such vehicles, shall restrain a force in the forward longitudinal direction of up to 2,000 pounds per securement leg or clamping mechanism and a minimum of 4,000 pounds for each mobility aid. Securement systems on vehicles with GVWRs of up to 30,000 pounds, and their attachments to such vehicles, shall restrain a force in the forward longitudinal direction of up to 2,500 pounds per securement leg or clamping mechanism and a minimum of 5,000 pounds for each mobility aid.

(2) Location and size. The securement system shall be placed as near to the accessible entrance as practicable and shall have a clear floor area of 30 inches by 48 inches. Such space shall adjoin, and may overlap, an access path. Not more than 6 inches of the required clear floor space may be accommodated for footrests under another seat provided there is a minimum of 9 inches from the floor to the lowest part of the seat overhanging the space. Securement areas may have fold-down seats to accommodate other passengers when a wheelchair or mobility aid is not occupying the area, provided the seats, when folded up, do not obstruct the clear floor space required.

(3) Mobility aids accommodated. The securement system shall secure common wheelchairs and mobility aids and shall either be automatic or easily attached by a person familiar with the system and mobility aid and having average dexterity.

(4) Orientation. In vehicles in excess of 22 feet in length, at least one securement device or system required by paragraph (a) of this section shall secure the wheelchair or mobility aid facing toward the front of the vehicle. In vehicles 22 feet in length or less, the required securement device may secure the wheelchair or mobility aid either facing toward the front of the vehicle or rearward. Additional securement devices or systems shall secure the wheelchair or mobility aid facing forward or rearward. Where the wheelchair or mobility aid is secured facing the rear of the vehicle, a padded barrier shall be provided The padded barrier shall extend from a height of 38 inches from the vehicle floor to a height of 56 inches from the vehicle floor
with a width of 18 inches, laterally centered immediately in back of the seated individual. Such barriers need not be solid provided equivalent protection is afforded.

(5) Movement. When the wheelchair or mobility aid is secured in accordance with manufacturer's instructions, the securement system shall limit the movement of an occupied wheelchair or mobility aid to no more than 2 inches in any direction under normal vehicle operating conditions.

(6) Stowage. When not being used for securement, or when the securement area can be used by standees, the securement system shall not interfere with passenger movement, shall not present any hazardous condition, shall be reasonably protected from vandalism, and shall be readily accessed when needed for use.

(7) Seat belt and shoulder harness. For each wheelchair or mobility aid securement device provided, a passenger seat belt and shoulder harness, complying with all applicable provisions of 49 CFR part 571, shall also be provided for use by wheelchair or mobility aid users. Such seat belts and shoulder harnesses shall not be used in lieu of a device which secures the wheelchair or mobility aid itself.

For more information see: http://www.access-board.gov/transit/html/vguide.htm

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A-11: Where can I get more detailed information about the activities of the standards working groups (draft standards, meeting minutes, reference documents, etc.)?

Answer:
The RERC on Wheelchair Transportation Safety has an archival web-site that contains documents from the period when wheelchair transport and seating standards were being developed. This site may be found by directing your web browser to: http://www.wheelchairstandards.pitt.edu/

Use the navigation bar to locate:

• ANSI/RESNA-SOWHAT-WC19: Wheelchairs Used as Seats in Motor Vehicles
• SAE-J2249: Wheelchair Tiedown and Occupant Restraint Systems
• ISO- 10542: Wheelchair Tiedown and Occupant Restraints
• ISO-7176-19: Wheelchairs for Use in Motor Vehicles
• ISO- 16840-4: Seating Devices for Use in Motor Vehicles

Within each organization you can also download a copy of meeting minutes, the draft standard prepared by the working group, or in some cases, copies of specific reference documents.

You will need a copy of Adobe Acrobat on your computer to open the file that is downloaded to your computer, since it will be in the .pdf format. If you don't already have one, you can download a free copy of Acrobat from Adobe.

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A-12: How can I help move this effort forward more quickly?

Answer:
Many manufacturers of both tiedowns/occupant restraint devices and wheelchairs have actively participated in the development of the standards as well as in testing their products to the standards. This has been a significant financial investment by the manufacturers to improve the transport safety of their products. Since compliance with the standards is voluntary, there are unfortunately still products that are being marketed that are clearly intended for use in motor vehicles that have not been tested to the standards. The single most effective way to rectify this problem is for consumers, parents, caregivers and prescribers to request, and whenever possible, purchase only products that have been tested to one or more of the appropriate transport standards. If the product is in compliance, it should be so labeled on the product.

For those interested in becoming more directly involved in the standards development process, there is a way that you can be added to the e-mail lists or working groups. The standards working groups are always open to manufacturers, researchers, transporters, consumers and clinicians who wish to contribute their experiences and participate in the research, testing, discussions, and debates that move the work forward. Although several of the key standards have now been completed, all standards are reviewed at least every five years, and are modified more frequently, if necessary. Secondly, new areas of standards development are now underway to in the initial development effort. For more information on how to become involved:

1. For the ANSI/RESNA Committee on Wheelchairs and Transportation (COWHAT) in the USA, contact Larry Schneider, Chair, RESNA COWHAT at lws@umich.edu
2. For International (ISO) Working Group or WG-6, contact the chair, Aleid Hekstra at edpc@handicom.nl

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A-13: Where can I get a complete copy of the current industry standards?

Answer:

In the United States:

The ISO standards were developed with strong participation from the U.S., therefore the harmonization between the US and the ISO efforts are much closer. At present, the completed U.S. transportation standards are as follows:

1. SAE J2249 (WTORS): Wheelchair Tiedown and Occupant Restraint Systems-for Use in Motor Vehicles (January 1996)

Source: Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096-0001. 1-877-606-7323 (U.S. and Canada only) or 724/776-4970 (outside the U.S. and Canada)
Web: http://206.160.145.240/about/contact.htm

As of March 2002, both SAE J2249 and J2252 are under revision and will be included in a new ANSI/RESNA Wheelchair Standards Volume 4 for standards and related documents dealing with transportation of wheelchair-seated occupants. This should increase harmonization with their more recently completed ISO counterparts. Note that, for the WTORS standard, the approach in the U.S. has been to develop one all-encompassing standard for wheelchair tiedowns and occupant restraints, whereas in the ISO, the approach has been to develop interrelated parts as indicated below.

1. ANSI/RESNA WC19: Wheelchairs Used as Seats in Motor Vehicles (May 2000)

Source: RESNA: 1700 North Moore Street, Suite 1540, Arlington, VA 22209-1903
Phone: 703-524-6686
Fax: 703-524-6630
TTY: 703-524-6639
e-mail:info@resna.org
Web: http://www.resna.org

International Standards or ISO:

1. 10542-Part 1: Wheelchair Tiedown and Occupant Systems- General requirements and test methods for all systems (Spring-2001)
2. 10542-Part 2: Wheelchair Tiedown and Occupant Systems- Four point strap-type tiedown systems (Spring-2001)

The current plans call for the ISO 10542 standard to ultimately contain five parts:

• 10542-Part3: Wheelchair Tiedown and Occupant Systems-Docking Systems (2003)
• 10542-Part4: Wheelchair Tiedown and Occupant Systems-Clamping Systems (2002)
• 10542-Part5: Wheelchair Tiedown and Occupant Systems-Systems for Specific Wheelchairs (2002)
• ISO 7176-19: Wheelchairs: Wheelchairs for Use in Motor Vehicles (Summer, 2001)
• ISO 16840-4: Wheelchairs seating: Seating Devices for Use in Motor Vehicles (2003)

Source: http://www.iso.ch/iso/en/ISOOnline.openerpage

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A-14: Where can I get more information about products that conform to the industry standards related to wheelchair transport safety?

Answer:
For more information on the products from specific manufacturers, we suggest you contact your local supplier on the manufacturer directly. The * indicates that these manufacturers actively participated in the development of the standards. Use the hyperlink to go to the manufacturer's website.

A. Wheelchair Securement and Occupant Restraint Products

*Sure-Lok 866 787-3565 www.sure-lok.com

*Q’Straint 800 987-9987 www.qstraint.com

New Haven Equipment 213 749-8181 www.newhaven-usa.com/

Ortho Safe Systems 609 587-9444 www.njcost.com/ortho_safe.htm

EZ Lock, Inc. 225 926-2403 www.ezlock.net/

B. Transport Wheelchair Products

See the complete listing of crash-tested and WC19 compliant mobility products on this site.

C. Wheelchair Seating Products

See the complete listing of crash-tested and WC19 compliant seating products on this site.

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A-15: What is the Rehabilitation Engineering Research Center (RERC) on Wheelchair Transportation Safety (WTS)?

Answer:
This Rehabilitation Engineering Research Center (RERC) is a five-year project (November 2006 to October 2011) funded by the National Institute of Disability and Rehabilitation Research (NIDRR). It is focused solely on the issues of transportation safety for occupants of motor vehicles who remain seated in their wheelchair. The RERC on WTS is a partnership between the University of Michigan Transportation Research Institute, the University of Louisville's Speed School of Engineering, the University of Pittsburgh's Department of Rehabilitation Science and Technology and the University of Colorado's Assistive Technology Partners.

In addition to focusing on research and development activities concerned with occupant protection for wheelchair travelers in side and rear impacts, the RERC also addresses issues of improved restraint systems and wheelchair seating systems. In addition, however, the RERC will expend considerable effort on the development and implementation of additional standards and on the dissemination of information related to these standards. Its goal is to focus its resources on the issues surrounding providing safer transportation and improved crash protection for wheelchair-seated travelers. The website address for the RERC on WTS is: http://www.rercwts.org/

The current RERC follows the first RERC on Wheelchair Transportation Safety (2001 to 2006). The work of the first RERC is archived on this website in the research section at http://www.rercwts.org/RERC_WTS_Research/RERC1_WTS_Research/RERC_WTS_res.html It forms the foundation for our current work.

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Group B. Questions: Wheelchair Tiedown and Occupant Restraint Standards (WTORS)

Question B-1: What are the requirements for tiedown and restraint products in order to comply with the wheelchair tiedown and occupant restraint standards? (WTORS: SAE J2249 and ISO 10542)?
Question B-2: What is the difference between an integrated and an independent occupant restraint system?
Question B-3: What do I do with very heavy wheelchairs? Will the wheelchair tiedowns be strong enough?
Question B-4: What should I do if I use a very heavy wheelchair that may generate forces that exceed the strength capacity of existing tiedown devices in a severe crash?
Question B-5: If I have a wheelchair with a tilting seat frame, what is the best way to secure the wheelchair to the vehicle?

B-1: What are the requirements for tiedown and occupant restraint products to comply with the wheelchair tiedown and occupant restraint standards (WTORS: SAE J2249 and ISO 10542)?

Answer:
Although there are some differences between the US (SAE-J2249) and the ISO (10542-1/2) standards, the general requirements and test methods are essentially identical and may be summarized as follows:

The standards apply to WTORS:

• that include all different types of wheelchair securement systems,
• with belt-type occupant restraint systems,
• with both passengers and drivers (adults only-ISO),
• for use in both public and private vehicles,
• for use with all wheelchairs including scooters, and
• for use with forward-facing wheelchairs in the vehicle.

The standards require that:

• pelvic and shoulder restraints be used in the tests and recommend use of both belts during transport, especially in vehicles that have occupant restraint belts normally installed,
• a dynamic 30 mph (48kph) frontal-impact test be used to confirm the performance of the WTORS,
• the end fittings on tiedown straps meet a specific design so that the end fitting will readily latch to the mating receptacle on the transport-compliant wheelchair,
• the product be permanently labeled as to the test passed,
• instruction and warnings be provided for both installers and users.

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B-2 What is the difference between an integrated and an independent occupant restraint system?

Answer:
An independent occupant restraint system is a vehicle-anchored belt restraint system that is anchored "independent" of the occupant’s seat or wheelchair to the vehicle structures. In an integrated restraint system, the anchor points for the restraint system are on the seat or wheelchair - i.e., it is a seat- or wheelchair-integrated restraint system. Integrated restraint systems are becoming more common in automobiles because the belts generally fit and perform better when they are anchored closer to the occupant on the vehicle seat. It is also possible to have a partially integrated restraint system, where only the pelvic belt is anchored to the wheelchair or vehicle seat, but the upper end of the shoulder belt is anchored to the side-wall of the vehicle. This, in fact, is what is required as an option on all WC19 wheelchairs after May 2002. If a wheelchair user chooses this option, he/she can have a pelvic/lap belt installed on the wheelchair that will include hardware for a standard interface connection to the lower end of a vehicle-anchored shoulder belt.

It is also possible to have a totally integrated belt restraint system where the anchor points for both the upper and lower torso belts are on the wheelchair. However, the upper anchor points will place high forces on the upper part of a wheelchair backrest in a frontal crash, and most wheelchair backrests would not be able to withstand these forces without significant design modifications. The totally integrated restraint system is probably most feasible and most important for smaller children, but the partially integrated pelvic/lap belt should be feasible for most wheelchair users and will improve pelvic belt performance, reduce the tendency for lap-belt "submarining" (i.e., going under the lap belt), and reduce interference with the wheelchair user's personal space when installing a belt restraint in a motor vehicle. For these reasons, WC19 requires wheelchairs to provide the wheelchair user with the option of using a wheelchair-anchored pelvic belt after May 2002.

Note: The term restraint is used exclusively in reference to the wheelchair occupant and the term tiedown or securement is used exclusively in reference to the wheelchair. A wheelchair is not restrained but is tied down or secured. An occupant is not secured, but is restrained in a motor vehicle.

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B-3 What do I do with a very heavy wheelchair? Will the wheelchair tiedowns be strong enough?

Answer:
SAE J2249 requires dynamic testing of wheelchair securement systems in a 30-mph frontal impact using a rigid surrogate wheelchair that weighs 187 lb. Clearly, the static mass of some commercial wheelchairs is greater than this surrogate wheelchair. In addition, if wheelchair occupants use belt restraints that anchor to the wheelchair (i.e., integrated) or even wheelchair-attached postural belts, the forces on the wheelchair securement system may be higher in a 30-mph crash than those to which the securement system has been tested.

What this means is that, under some relatively severe crash conditions, the user of a very heavy wheelchair may be at somewhat greater risk than the user of a lighter wheelchair. However, in considering this apparent disparity between SAE J2249-required WTORS strength and potential real-world loading scenarios, it is important to remember that the likelihood of a 30-mph crash is low even in vans and minivans. The likelihood is even lower in larger vehicles such as school buses and transit buses. Thus, for the large majority of frontal crashes, the user of a very heavy wheelchair that meets WC19 will still be provided with effective wheelchair securement. If the desire is to reduce the risk to the wheelchair occupant in higher severity crashes when traveling in vans and minivans, then additional tiedown straps can be installed for use with a heavier WC19-compliant wheelchair.

Remember that WC19 requires that wheelchairs with a mass up to 400 lb be successfully crash tested at 30 mph. Thus, heavy WC19-compliant wheelchairs, regardless of their mass, have demonstrated that they can deal with the forces generated by their own mass in a 30-mph frontal crash using the securement points provided and specified in the manufacturers literature. Therefore, the use of a heavy wheelchair that has been tested to the WC19 standard will reduce the risk of ineffective wheelchair securement for most real-world crashes.

Finally, the disparity between the dynamic strength of wheelchair tiedowns and the potential loads imposed by heavy wheelchairs continues to be concern. It is useful to realize that there has been, and continues to be, a much greater disparity between the strength of SAE J2249-compliant tiedowns and most non-WC19-compliant wheelchairs that are secured in vehicles by these tie-downs. In these situations, the wheelchair is the weak link in the system. This issue of disparity in strength between wheelchair and securement system is much more prevalent and a much greater concern in occupant safety for wheelchair-seated travelers than is the disparity between the potential loads imposed on wheelchair tiedowns by heavy wheelchairs in high-severity crashes. Thus, while the concern for strength limitations of wheelchair tiedowns should be a consideration when transporting occupants in heavy wheelchairs, it needs to be kept in the proper perspective with regard to the overall merits and benefits of using wheelchairs that comply with WC19.

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B-4: If I use a very heavy wheelchair that may exceed the capacity of existing tiedown devices, when should I use additional tiedown straps?

Answer:
The question of when and whether to use additional tiedown straps is up to the wheelchair user, the transit provider, etc. and depends on a number of factors. The answer probably also depends on whether the wheelchair complies with a transport standard (WC19), as will be explained shortly. For heavy wheelchairs that do NOT comply with the transport standard, the more straps the better. However, finding four suitable securement points (much less, more than 4!) is problematic on many wheelchairs, and of course none of these additional securement points have been dynamically tested.

The need for additional straps also depends on the type of vehicle and transit mode. For large city buses and large school buses, more than four straps is probably not warranted, especially for transport-tested wheelchairs, since this type of vehicle is very unlikely to ever experience a 30-mph crash to which tiedown straps that comply with tiedown standards have been tested.

Another factor that could influence the decision about whether and when to use additional tiedowns is whether the occupant is restrained by belts that anchor to the wheelchair (i.e., integrated restraints) or restraint belts that anchor directly to the vehicle. In other words, when the occupant restraint loads are combined with the heavy wheelchair loads, the combination may exceed the capacity of only two rear tiedown straps.

For a WC19 compliant wheelchair, the standard allows wheelchairs that weigh more than 275 lbs. to provide for more than four securement points (e.g., 3 or 4 in the back). It also requires that the manufacturer's presale literature indicate the number of securement points and tiedown straps used in the frontal impact test, if the number is greater than the minimum of four. Note that wheelchairs weighing less than 275 lb must pass the test with only four securement points and that wheelchairs weighing more than 275 lbs don't have to provide more than four securement points.

However, whether or not a wheelchair has been tested with four, or more than four tiedown straps, the decision of whether to use four or more tiedowns in the real world may be different. For example, if a 280 lb wheelchair is tested using five securement points with three of these for rear securement, a transit provider for large city buses or large school buses might decide to use only two of these rear securement points, since a large vehicle is extremely unlikely to ever experience anything close to a 30 mph impact. Similarly, if a 200 or 250 lb wheelchair is used in a van-sized vehicle that travels the highways, the user or transit provider might decide to use four rear tiedown straps instead of just two, particularly for occupants with a pelvic belts anchored to their wheelchairs. This can be done because the geometry of the securement points required by the standards will allow two tiedown straps to be attached to each of the rear securement points.

In summary, the questions about whether to use more than four tiedown straps for heavier wheelchairs and for situations with wheelchair-integrated restraints, and at what wheelchair mass to implement additional tiedowns do not have simple answers. The answers depend not only on the type of vehicle and travel mode, but also on how much additional risk you are willing to trade off for the convenience of using only four tiedown straps instead of more than four straps. If you are very conservative and don't want any additional risk, and are willing to put up with additional time and effort to secure a wheelchair, then you might decide to use four rear tiedown straps in a van-sized vehicle whenever the wheelchair mass exceeds 250 lbs. However, if you are willing to take some additional risk (maybe not protect the wheelchair occupant quite as well in 25 - 30 mph impacts, because reduced time and effort is very important) then you might not use more than two rear tiedown straps for wheelchairs that weigh as much as 250 lb in a van-sized vehicle. At no time, however, should one use less than four transport-tested tiedown straps, two in the rear and two in the front.

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B-5: If I have a wheelchair with a tilting (tilt-in-space) seat frame, what is the best way to secure the wheelchair to the vehicle?

Answer:
The answer to this question depends somewhat on whether you are dealing with a WC19-compliant wheelchair or a non-WC19wheelchair. For non-WC19wheelchairs that do not have designated securement points and that do not comply with WC19 (People are going to have to deal with this issue for the foreseeable future.) it is generally recommended that both the front and rear securement points be either on the front and back of the seat or on the front and back of the wheelchair frame or base (presuming it is possible to find four relatively strong attachment points on the wheelchair frame on either part of the wheelchair). This is done to minimize the chance of extreme slack developing in the tiedown system which would occur if the seat tilt angle changes, resulting in large changes in distance between points on the wheelchair base at one end of the wheelchair and points on the wheelchair seat at the other end. In addition, it is recommended that these four points be on the seat, since these points will usually provide slightly steeper tiedown strap angles that increase wheelchair stability and reduce upward movement of the wheelchair in a crash situation.

For WC19-compliant wheelchairs, however, it is not as important for all four securement points to be on the seat or on the base. This is because a WC19-compliant tilt-in-splace wheelchair will have been dynamically strength tested using the securement points provided by the manufacturer, wherever they are. It is, however, still preferable for the securement points to be located high on the wheelchair base or seat frame, rather than down low near the floor (note the minimum height allowed by WC19 is 100 mm = 4”) to increase wheelchair stability during transit and reduce upward motion and pivoting of the wheelchair in a frontal crash. However, even though manufacturers are placing securement points lower on some WC19-compliant wheelchair frames than is preferred, these wheelchairs have complied with the WC19 test and have therefore demonstrated effective crash performance with these locations.

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Group C. Questions: Transport Wheelchair Standards (ANSI/RESNA WC19, ISO 7176-19)

Question C-1: What is WC19 and what is its purpose?
Question C-2: Why is WC19 needed?
Question C-3: What is the scope of WC19 and what does it require?
Question C-4: What is the benefit to purchasing a wheelchair that complies with WC19?
Question C-5: What will be different about WC19 wheelchairs?
Question C-6: Does designing a wheelchair to comply with transport standards conflict with the other features and functions of wheelchairs that are important to wheelchair users on a daily basis?
Question C-7: What is the basis for the 30-mph frontal-impact requirement of WC19?
Question C-8: Why does WC19 require that wheelchairs used in transportation be designed for securement using a four-point, strap-type tiedown?
Question C-9: Where should wheelchair securement points be located?
Question C-10: Are there special considerations for locating securement points on wheelchairs with tilt-in-space seating systems?
Question C-11: Should wheelchair manufacturers set special limits on the weight of occupants who can use WC19 wheelchairs?
Question C-12 Do I always need to replace a WC19 wheelchair following a crash or sudden stop?
Question C-13: What tilt and recline angles are acceptable in motor-vehicle transportation and what are the potential negative consequences of reclining an occupant too much?
Question C-14: What does WC19 say about head restraints and what should I do for rear-impact protection?
Question C-15: Will I be denied access to transport vehicles if I do not have a WC19 compliant wheelchair?
Question C-16: Can a non-WC19-compliant wheelchair be retrofitted to include the 4 securement points?
Question C-17: What if I want to secure my wheelchair by something other than a four-point, strap-type tiedown? Can this be crash tested?
Question C-18: Is it OK if I make modifications to a WC19 wheelchair?
Question C-19: What does the standard say about auxiliary equipment on WC19-compliant wheelchairs, such as trays, oxygen tanks, and other add-on equipment that may be necessary for the particular wheelchair user?
Question C-20: Can wheelchair scooters and stroller type wheelchairs comply with WC19?
Question C-21: How do I secure wheelchairs that do not comply with WC19?
Question C-22: Do you have any general information on the ANSI/RESNA WC19 standard that our organization could use in its monthly newsletter?
C-23: What is the difference between ANSI/RESNA WC19 and ISO 7176/19?  If I comply with the requirements of one of these standards, do I comply with the other one?

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