Effects of human-machine interaction mechanisms on situation awareness in partly automated driving

In recent years, one of the goals of driver assistance systems has been to relieve the driver of parts of his burden of driving. Current developments are able to take over full control of the vehicle in specific use cases. Automated driving in traffic jams is seen as the next step towards automated driving. One of the main challenges is ensuring the driver´s ability to take back responsibility when being driven by the car. The assumption that drivers tend to perform secondary tasks creates a target conflict. Within this context, it is the aim of the current study to analyze the impacts of an exemplary secondary task and certain Human-Machine Interaction (HMI) mechanisms on the driver´s level of situation awareness and the resulting driving safety. The implemented HMI mechanisms are a “driver´s safety device” and a “video image”. While it is hypothesized that the secondary task has a negative influence on situation awareness, the HMI mechanism´s effect is supposed to be positive. In addition, the overall user´s acceptance will also be analyzed. The results show that the implemented driver´s safety device has no effect on situation awareness but is still able to support driving safety by assisting the driver in the execution of actions. The video image has a positive effect on situation awareness but because the complacency-effect is enhanced its effect on driving safety is negligible. As assumed, the secondary task has a negative impact on situation awareness and driving safety.