Exploring the Impact of Haptic Feedback Locations and Mid-air Haptic Technology on Driver's Takeover Performance in Automated Vehicles

Automated vehicles enable drivers to engage in non-driving-related tasks, shifting their roles and introducing challenges for effective human-machine interfaces in managing takeover requests. This study examines the impact of haptic feedback locations (i.e., hand and face) and technologies (i.e., vibrotactile and ultrasonic mid-air haptic) on the driver's takeover performance. In the experiment with 32 participants, results showed that feedback on the face led to significantly faster simple reaction times than on the hand. Additionally, vibrotactile feedback resulted in quicker takeover reaction time and lane change time compared to mid-air haptic technology. These findings highlight the importance of feedback location and technology in safety-critical scenarios and offer insights for designing more intuitive and effective takeover request mechanisms to improve driving safety in future automated vehicles.