A Longitudinal Simulator Study to Explore Drivers' Behaviour During Highly-Automated Driving

Six experienced drivers each undertook five 30-min journeys (portrayed as 'daily commutes' i.e. one on each of five consecutive weekdays) in a medium-fidelity driving-simulator engineered to mimic a highly-automated vehicle. Participants were encouraged to act as they might in such a vehicle by bringing with them their own objects/devices to use. During periods of automation, participants were quickly engrossed by their chosen activities, many of which had strong visual, manual and cognitive elements, and required postural adaptation (e.g. moving/reclining the driver's seat); the steering wheel was typically used to support objects/devices. Consistently high subjective ratings of trust suggest that drivers were unperturbed by the novelty of highly-automated driving and generally willing to allow the vehicle to assume control; ratings of situational awareness varied considerably indicating mixed opinions. Qualitative results are discussed in the context of the re-design of vehicles to enable safe and comfortable engagement with secondary activities during high-automation.