Cross-modal feedback of tactile and auditory stimuli for cyclists in noisy environments

In recent years, with the increasing use of bicycles for environmental and health benefits, the importance of the feedback for cyclists is increasing. Moreover, as bicycles account for 23 % of all traffic accidents in 2022, improving bicycle safety is a crucial challenge. This study aimed to explore methods for enhancing safety and improving feedback to cyclists through auditory and tactile signals. Experiments were conducted using a cycling simulator and cross-modal reaction tests of tactile and auditory signals to simulate bicycle riding under actual external noise environments. The accuracy of the recognition and reaction times for both tactile and auditory signals were evaluated in situations with simulated road traffic sounds. Subsequently, the effectiveness of cross-modal feedback was assessed, optimal signal conditions were examined, and the relationship between variations in environmental noise and optimal auditory signals for cyclists was discussed. The results showed that cross-modal feedback led to faster reaction times, while the recognition accuracy of auditory signals varied depending on environmental noise levels. The present findings suggest the potential of cross-modal feedback to enhance cyclist safety, particularly when optimized for environmental conditions and individual perception. • Back of head is the most effective location for delivering warning signals. • Cross-modal feedback led to faster reaction times. • Recognition accuracy of auditory signals varies depending on environmental noise level.