Improving Time to Take Over Through HMI Strategies Nudging a Safe Driving State

In scenarios of partially autonomous driving, drivers can easily become distracted and engage in secondary activities unrelated to driving. However, when it becomes necessary to take-over the control, they must be in the right conditions to resume driving safely. This article explores the design and evaluation of a Human-Machine Interface (HMI) that, leveraging the knowledge of the driver’s state enabled by intelligent driver monitoring systems, helps the driver stay focused on the road in case of distraction and relax in case of agitation. The article presents the results of an experimental campaign in a driving simulator with 11 participants, aimed at measuring the advantage in terms of take-over reaction times with or without the proposed solution. This advantage was measured in terms of hands-on-wheel time through video analysis and eyes-on-road time through eye-tracking data analysis. The results demonstrate significant advantages both in terms of reaction times and from the perspective of user experience. The study allowed the identification of new research insights for further exploration of interface strategy.