Abstract
When wheelchair users drive a vehicle, they have to use driving support equipment to compensate for their disability. Also, the drivers are forced to match themselves to the vehicle. For safety improvement, it is important that the driving environment is streamlined in regard to physical function. The purpose of this research is to understand the operational characteristics and physical conditions of wheelchair users when driving, and to study the driving environment in order to reduce driving load. In this research, movements of the head and muscle load of the shoulders and lower arms were analyzed while driving on curves, and the compatibility for wheelchair users on a driving environment, which was basically designed for physically unimpaired people, was studied. As a result, it was found that around the end of the curve, the balance between centrifugal force and maintaining body posture collapsed and, therefore, the body balance became unstable. In this situation, the steering operation is affected and, consequently, there is a risk of the vehicle swerving. Also, the acceleration-break lever or steering wheel was used to maintain body balance, so it became difficult to adjust operation of the vehicle, and it also became difficult to drive along the correct course of the road.
