The role of take-over cue informativity in interrupted take-over requests in a semi-automated driving scenario

In semi-automated driving, take-over requests (TOR) signal the driver to take over control, if the car's driving system is not able to handle a particular traffic situation autonomously. While previous research indicated that providing informative TORs aids take-over behavior, related experimental research on task cuing suggested that informative cues might also be harmful, if interrupted by another task. Hence, the present study tested whether the advantage of informative TORs diminishes if after a TOR cue an interrupting task is presented. This should resemble a scenario, where drivers are about to take over control in response to a TOR, but then are distracted, for example by an incoming phone call. To this end, we presented participants with videos of a semi-automated driving situation, where task-specific informative or generic, non-informative TOR cues indicated an upcoming take-over action. Crucially, in half of the trials, this TOR cue was interrupted. Results showed informative TOR cues to generally improve take-over performance, but the interrupting task to reduce the advantage of providing informative TORs. However, this effect took some time until it reached its maximum and vanished with further practice. In sum, the present study identified interrupting, distracting information and practice as factors moderating the effectiveness of TOR cues, which demand further consideration in the research of semi-automated driving.