For applying ISO 26262 to motorcycles, controllability classification (C class evaluation) by expert riders is considered an appropriate technique. Expert riders have evaluated commercial product development for years and can appropriately conduct vehicle tests while observing safety restrictions (such as avoiding the risk of falling). Moreover, expert riders can ride safely and can stably evaluate motorcycle performance even if the test conditions are close to the limits of vehicle performance.
This study aims to construct a motorcycle C class evaluation method based on an expert rider’s subjective evaluation. On the premise that expert riders can rate the C class, we improved a test procedure that used a subjective evaluation sheet as the concrete C class evaluation method for an actual hazardous event. The evaluation sheet included the C class table, in which the classifications are defined by the percentage of representative riders who could avoid harm, and a table of supplementary descriptive items indicating the background behind the C class evaluation result.
Using this method, four expert riders evaluated the C class in tests that reproduced various hazardous events. This study introduced examples of C class evaluations for scenarios involving “unintended acceleration on a straight road” and “insufficient braking force during deceleration”.
The C class evaluation results of this and previous studies were summarized for each hazardous event. From these results, we concluded that the C class evaluation method considered in this study is appropriate for motorcycle C class evaluations.
