Exploring the Behaviour of Distracted Drivers during Different Levels of Automation in Driving

Increased levels of automation in driving can reduce drivers’ situation-awareness and cause erratic changes to workload and skills degradation following prolonged exposure. In addition, drivers (particularly those who are vulnerable to the onset of boredom/fatigue) may engage in non-driving related, and potentially distracting, secondary tasks. Understanding the behavioural cues associated with this change in driver state can assist in the design and development of future driver monitoring systems that intervene in instances where a driver exhibits ‘high’ levels of distraction. The aim of this study was to explore the behavioural cues associated with distraction caused by a non-driving related secondary task (pseudo-text reading) during manual, partially-automated and highly-automated driving in a mediumfidelity driving simulator. Results from thirty drivers show that highly-automated driving was characterised by reduced workload, increased secondary task times and longer in-vehicle glances, compared to manual and partially-automated driving. In contrast, partially-automated driving was characterised by high workload, poor secondary task performance and low levels of situation awareness. Furthermore, primary and secondary task performance immediately following take-over during partiallyautomated driving was significantly compromised. The results indicate that the same type of ‘distraction’ can elicit different behavioural cues depending upon the level of automation within driving. This information can be used to further the development of future driver monitoring systems.