Physiological measurements of passengers in self-driving cars encountering unexpected road events

In a preliminary analysis investigating the EEG and eye movement patterns of car passengers’ significant differences were reported in human driven and self-driving trials [15]. The differences suggested a preference and lower levels of anxiety in human driven conditions. The aim of the study reported here was to relate these differences to unexpected road events in real life passenger experience. These events were quick path corrections due to unforeseen obstacles on the path (deer and human shaped dummies). Every passenger went through both human and self-driving trials. The order of trials was balanced. Besides EEG and eye movements head movements and blinking frequencies were also recorded. Overall EEG and eye-tracking results were comparable to the preliminary findings showing the same overall differences between conditions. Analyses targeting the unexpected events showed moderate affective preferences for human drivers in the EEG data. Analyses of eye movements and head movements revealed larger multifractal spectrum differences for events vs smooth travel compared to human vs self-driving conditions. Blinking frequencies during the trip were lower during unexpected events, indicating higher levels of alertness.