Development of Surface Roughness Standards for Pathways Used by Wheelchair Users: Final Report

5. Conclusions

WC users are exposed to WBVs that can be harmful and uncomfortable. Some characteristics of the WC can be adjusted to minimize these WBVs such as adding suspensions systems, using larger more compliant wheels, etc. However, any changes to a WC to reduce vibrations can cause negative outcomes to other performance properties such as its weight and resistance to propelling. This study found that surface characteristics, more specifically surface roughness, can have a large impact on the WBVs that WC users are exposed to.

Engineered surfaces showed that there is a high correlation between surface roughness and the WBVs which WC users are exposed to as well as their perceived comfort level while traveling over these surfaces. Manual WCs users are more susceptible to harmful WBVs, and as surface roughness increases, they are exposed to a larger increase in vibrations than power WC users.

A standard is being developed that would restrict new surfaces from being installed that would likely result in harmful WBVs to WC users who will use that surface to access their community. The goal is for the standard to be developed with and approved by ASTM International and then approved by the United States Access Board. The standard will then be used by city planners, construction workers, surveyors, etc. to evaluate if a current surface meets the standard or should be replaced. Software will also be developed to determine if a new design for a surface will meet the standard once it is installed.