Study on the Impact of Ehmi on the Interaction between Cyclists and Fully Autonomous Vehicles

Fully autonomous vehicles (FAVs) have the potential to improve road safety and reduce traffic congestion and emissions, but many are skeptical due to the lack of drivers. To compensate for the lack of a driver in a FAV, an external human-machine communication interface (eHMI) can be used to communicate with other users on the road. However, the effect of eHMI on cyclists' self-perception remains uncertain. The purpose of this study was to investigate the effects of eHMI technology on cyclists' behavior and safety awareness. Demographic information (such as gender, age, and education level), road behavior (violations, mistakes, positive behaviors), and their acceptance of FAVs (social norms, attitudes, behavioral intention etc.) are collected through online surveys. Six scenarios in which cyclists interact with cars are designed. In each scenario, the potential collision risk was simulated, and the impact of eHMI on cyclists' self-protection intentions (such as braking, lane change, etc.) was analyzed by comparison. A total of 895 respondents took part in the survey. The findings indicated that male and younger cyclists exhibited a higher level of acceptance towards FAVs. Cyclists who had an accident within the past two years were more willing to share the road with FAVs. The younger cyclists demonstrated superior responsiveness and comprehension of the eHMI signal in comparison to their older counterparts. Additionally, cyclists with a higher level of education exhibited enhanced utilization ability of eHMI information and displayed more self-protective behavior. The research will offer significant theoretical and practical insights for the advancement of human-machine interactions in the context of FAVs and cyclists.