Revisiting Clear Floor Area Requirements for Wheeled Mobility Device Users in Public Transportation.

Current accessibility standards in the U.S. prescribe minimum dimensions for 'clear floor area' to accommodate wheeled mobility device (WhMD) users on transportation vehicles. Prior research on the anthropometry of WhMD users ( = 500) indicates that these dimensions are too small to accommodate the size of many occupied wheeled mobility devices, especially power chairs and scooters. This paper describes a development project designed to update the evidence for these technical criteria and communicate them to the vehicle designers and accessibility standards developers in a manner that would facilitate making good decisions. An interactive web-based design tool was developed for determining the dimensions of clear floor area to achieve a user-specified level of physical accommodation based on occupied device length and width measurements taken on 500 WhMD users. The web-based design tool is now available to practitioners who seek to accommodate a wider range of WhMD users than the minimum standards required by regulations. The design tool is also intended as a visual evidence base for regulatory activity and universal design practice with higher ambitions. The advent of driverless automated vehicles will increase the importance of accessibility and usability to accommodate the diversity of riders with disabilities. Clear floor space to enable independent ingress, interior circulation and egress among WhMD users will be a foremost concern. The transportation industry, standards developers, disability advocates, mobility device manufacturers and prescribers need to understand the limitations of current accessibility standards and work to address these limitations through updated vehicle design standards and policies.