Differences in the levels and the transverse and longitudinal gradients on sidewalks can seriously hinder the mobility of wheelchair users. On sidewalks where such differences and gradients are minor, the mobility of wheelchair users can be seriously hindered by surface unevenness in the case of rough sidewalks. This paper analyzes the longitudinal profiles of sidewalks in service and torque data for traveling wheelchairs with the goal of proposing a method for evaluating the surface unevenness of sidewalks based on the travel resistance imposed on wheelchairs. A test track with variable gradients and unevenness was traveled by panel members, who were then asked to rate the subjective discomfort of the test track. The study revealed a strong correlation between the surface unevenness values calculated by the proposed method and the discomfort rating offered by the panel members.