Mitigating psychological discomfort during automation error: A mixed methods research

Automated driving errors can threaten occupants' psychological comfort, creating a need for effective in-vehicle recovery communication. Recovery strategies refer to communicative system responses delivered after automation errors to mitigate negative impacts and restore positive interaction. This mixed-methods study examined how four recovery strategies (explanation, apology, promise, and denial) and two speech styles (machine-like and human-like) influence occupants' psychological comfort, operationalized as perceived safety and pleasure, after an automation error. Thirty-four participants completed a within-subjects driving simulator experiment and semi-structured interviews. Explanation and promise most effectively improved both dimensions, whereas denial impaired occupant experience. Apology showed a style-dependent reversal: human-like apology increased pleasure but reduced perceived safety. Machine-like delivery produced stronger overall benefits for perceived safety, but speech-style effects depended on strategy content. These findings suggest that recovery communication should align strategy content with the informational demands of the event and the expressive register of delivery.