Influence of unexpected events on driving behaviour at different hierarchical levels: a driving simulator experiment

Computer based simulation models of human driving behaviour can be used effectively to model driving and behavioural adaptation to Intelligent Transport System (ITS). This can be a useful step in human centered design of ITS. To construct a comprehensive model of driving behaviour, the interaction between the three levels of the driving task has to be determined. This gives insight into how different driving tasks influence each other. A driving simulator experiment was conducted to determine the relationship between levels of the driving task. The influence of workload on this relationship was determined by giving subjects an additional cognitive task. Subjects had to drive many similar intersections, until an unexpected event occurred. Their reaction on the tactical level to the compensation on the control level was measured. Participants lowered speed and increased headway after having to brake; level of unexpectedness increased this effect. Workload decreased this effect on driving speed