Active Vehicle Motion as Feedback during Different Levels of Automation

Different levels of automation require various tasks of the driver. During assisted and partially automated driving, the driver has to supervise the system and the environment, whereas the driver can engage in non-driving related tasks during highly automated driving. A future vehicle can combine various level of automation. The system should transparently feed back information about the system's state and its intentions in order to support the driver in his tasks. Therefore, the feedback should be comprehensible, comfortable, and useful for the driver. A driving study (N =60) in which an automation system performed vehicle guidance was conducted in real traffic on a highway. Participants were split into three different levels of automation (assisted, partially automated, and highly automated driving) and experienced two feedback concepts, one having active vehicle motions and one without motions. The results revealed that both feedback concepts were trustworthy, accepted and comfortable. However, it also became apparent that the ratings for both feedback concepts depended on the different levels of automation. Moreover, experience with adaptive cruise control had a significant influence on the evaluation.