Autonomous driving with an agent: speech style and embodiment

A driving agent can be an effective interface to interact with drivers to increase trust towards the autonomous driving vehicle. While driving research on agent has mostly focused on the voice-agent, little empirical findings on the robot-agent were reported. In the present study, we compared three different agents (informative voice-agent, informative robot-agent, and conversational robot-agent) to investigate their effects on driver perception in Level 5 autonomous driving. A driving simulator experiment with an agent was conducted. Twelve drivers experienced a simulated autonomous driving and responded to Godspeed questionnaire, RoSAS questionnaire, and social presence. Drivers rated the conversational robot-agent as significantly more competent, warmer, and providing higher social presence than the other two agents. Interestingly, despite this emotional closeness, drivers' attitude toward the conversational robot-agent was contradictory. They mostly chose the conversational robot-agent as the best option or the worst option. Findings of the present study are meaningful as a first step of exploring the potential of various types of in-vehicle agents in the context of autonomous driving.