The effect of footway crossfall gradient on wheelchair accessibility.
Doctoral thesis, UCL (University College London).
This thesis investigates the effect of footway crossfall gradients (0 %, 2.5 % and 4 %) on wheelchair accessibility. This is done by instrumenting both a self-propelled and attendant-propelled wheelchair and asking a convenience sample of people to push the wheelchair in a straight line. Accessibility has been measured using the Capabilities Model. In particular the provided capabilities of the wheelchair users have been measured. These have been modelled as the interactions between the user and the wheelchair, specifically the amount of force it takes to start the wheelchair, the work needed to keep the wheelchair moving and the force needed to stop the wheelchair. It is found that although the amount of work needed to traverse a footway remains constant regardless of crossfall gradient, a positive crossfall requires a second provided capability: the ability to apply different levels of force, and as a result work, to the upslope and downslope sides of the wheelchair. How people produce this difference of force is investigated. It is found that for self-propulsion, there are four strategies employed: the first is to reduce the force on the upslope side by pushing less hard, the second to increase the force on the downslope side by pushing harder, the third is to apply braking forces to the upslope wheel and fourthly to travel at a slower speed. These are either used independently or in combination. For the crossfall gradients tested it was found that attendants did not have to apply a negative (pulling) force to the upslope handle, and were able to combat the increased gradient by simply pushing harder on the downslope side. The thesis concludes that current crossfall guidelines of 2.5% seem reasonable, and that inexperienced users may struggle when these guidelines are exceeded.
|Title:||The effect of footway crossfall gradient on wheelchair accessibility|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Civil, Environmental and Geomatic Engineering|
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