(Over)Trust in Automated Driving: The Sleeping Pill of Tomorrow?

Both overtrust in technology and drowsy driving are safety-critical issues. Monitoring a system is a tedious task and overtrust in technology might also influence drivers' vigilance, what in turn could multiply the negative impact of both issues. The aim of this study was to investigate if trust in automation affects drowsiness. 30 participants in two age groups conducted a 45-minute ride in a level-2 vehicle on a real test track. Trust was assessed before and after the ride with a subjective trust scale. Drowsiness was captured during the experiment using the Karolinska Sleepiness Scale. Results depict, that even a short initial system exposure significantly increases trust in automated driving. Drivers who trust the automated vehicles more show larger signs of drowsiness what may negatively impact the monitoring behavior. Drowsiness detection is important for automated vehicles, and the behavior of drowsy drivers might help to infer trust in an unobtrusively way.