Should I take over? Does system knowledge help drivers in making take-over decisions while driving a partially automated car?

Abstract Partially automated car systems are expected to soon become available to the public. However, in order for any of the potential benefits of automated driving to arise, the driver and car need to establish effective, efficient and satisfactory interactions. Otherwise, the driver may rely too much on the automated car system, leading to dangerous situations or not relying on the system at all, making the automation pointless. This study studied whether the current method of providing information on (automated) car systems to drivers, which is mainly through owner’s manuals, can bring the driver’s mental model in accordance with the car’s capabilities. A total of 28 participants took part in a video- based driving simulator experiment. The participants were split into two groups: the first received no information about the system while the second did receive specific information about functionalities and system limitations. Each participant was seated in a driving simulator and experienced a partially automated car driving in city situations by means of videos projected on the outer screen. Participants were asked to indicate through the push of a button on the steering wheel if they felt that the car could no longer cope with the situation, and would take back control from the car if they were driving it on the real road. Each video was categorized as ‘requires a take-over’ or ‘does not require a take-over’ before the experiment, based on the system descriptions the participants received. Overall, the system information did not appear to support the participants in correctly deciding whether to take over or to rely on the system. The mental models of the participants did not seem to (sufficiently) change through the system information. Owner’s manuals may not be sufficient for future systems to provide drivers the necessary tools to be able to decide whether it is necessary to take back control of the car. In-vehicle support, tuned to the driver and the specific situation may be needed to safely guide this process.