Understanding Explanation Content for Cognitive and Affective Trust in Automated Vehicles

Trust is essential for the adoption and success of automated vehicles (AVs); however, many users remain skeptical about transferring control to these technologies. To build trust, AVs can provide explanations about their decisions, but what types of explanations matter most? This research explores how different kinds of AV explanations—describing what the vehicle is doing, explaining why it is doing it, or combining both elements—influence user trust. Through an experiment involving 121 U.S. drivers who viewed simulated driving scenarios, this study examined the effects on cognitive trust (related to perceptions of reliability and competence) and affective trust (related to emotional connection). The results indicate that providing explanations significantly improves cognitive trust compared to offering no explanations at all. More importantly, explanations that include reasons for actions particularly enhance affective trust, helping users feel emotionally connected to AVs. This study highlights the importance of transparent communication in AV design, showing that effective explanations are crucial not only for fostering user understanding but also for developing lasting emotional connections. These insights can guide future AV designs that encourage broader public acceptance and trust in automated driving technologies.