In the context of automated driving, a monitoring request (MR) is a means to prepare drivers for a take-over event. However, driver compliance may be an issue because not all MRs require a take-over. In this study, we investigated how drivers’ compliance with MRs was associated with previously experienced scenarios. The compliance level was measured based on drivers’ eye, hand, and foot preparatory behaviours retrieved from manual video observation. Although drivers showed good overall compliance by looking up to the road in response to MRs in all cases, hand and foot preparatory behaviour appeared to deteriorate after experiencing an MR without a critical event, and increased after a take-over event. Results further showed a positive association between preparatory behaviour and take-over performance.@en

An important question in automated driving research is how quickly drivers take over control of the vehicle in response to a critical event or a take-over request. Although a large number of studies have been performed, results vary strongly. In this study, we investigated mean take-over times from 129 studies with SAE level 2 automation or higher. We used three complementary approaches: (1) a within-study analysis, in which differences in mean take-over time were assessed for pairs of experimental conditions, (2) a between-study analysis, in which correlations between experimental conditions and mean take-over times were assessed, and (3) a linear mixed-effects model combining between-study and within-study effects. The three methods showed that a shorter mean take-over time is associated with a higher urgency of the situation, not using a handheld device, not performing a visual non-driving task, having experienced another take-over scenario before in the experiment, and receiving an auditory or vibrotactile take-over request as compared to a visual-only or no take-over request. A consistent effect of age was not observed. We also found the mean and standard deviation of the take-over time were highly correlated, indicating that the mean is predictive of variability. Our findings point to directions for new research, in particular concerning the distinction between drivers’ ability and motivation to take over, and the roles of urgency and prior experience.@en