Analysis of time delay in user´s awareness of ACC system mode transitions

This study investigates a mode confusion factor formal methods like the composite model analysis do not address. Our focus is placed on the user´s actual mental model about a mode-based automated system behavior. We try to examine effects of the user´s model of the mode mechanism onto mode awareness performance even when the user interface provides a correct and succinct description of the system. A driving simulator experiment using the ACC system is used to evaluate how much influence incorrect parts of the driver´s mental model have on his/her response time taken for detecting mode changes.