In-vehicle safety devices: Deliverable D1. Guarding Automobile Drivers through Guidance, Education and Technology (GADGET)

What are we actually doing when driving? What human abilities are necessary to perform the task and which factors influence the behaviour? This is discussed as a basis for the chapters to come, which are outlining possible effects of introducing different types of in-vehicle Safety Devices (SDs) from a psychological point of view, as well as methodological requirements to enable the assessment of the safety potential of SDs. The driving task is described as composed of task components at three different hierarchical levels: strategic, tactical and control tasks. The task demands imposed on the driver are met by also three levels of driver control/behaviour: knowledge-based, rule-based and skill-based. To match the task demands by appropriate driving behaviour the driver must possess certain perceptual, cognitive and motor abilities. When the two hierarchical frameworks are combined it is obvious that there is not an inherent unambiguous relationship between driver control (behaviour) and task requirements. It is concluded that driving, after the first novice phase, to a large extent is automatised and performed using behavioural rules (schemas) developed through practising the driving task. The importance of appropriate expectations and predictions is stressed. It is pointed out that implementing various in-vehicle Safety Devices (SDs) will influence the driving task by changing or removing certain sub-tasks and adding others. Examples are given. Another conclusion is that repertoires of driving skills and rules developed by drivers have to be modified when SDs are introduced. Expectations and predictions have to include mental representations of the SD functionalities. SD related factors expected to influence the driving task and the driver behaviour as well as their connection are listed.