A Strategic Institute Program (SIP) on 'Driver Behaviour Models' is currently running at the Institute of Transport Economics (TOEI). The program was established in 1998 and will end in 2002. Main reasons for establishing the program has been a lack of satisfactory driver behaviour models in traffic safety research, disagreement on the theoretical bases for understanding driver behaviour, and the fact that driver behaviour models, to a large extent, lack factors concerning information processing and decision-making. A better theoretical base is also strongly needed because of the phenomenon often referred to as risk compensation, i.e. the observation that some traffic safety measures, aimed at reducing the number of traffic accidents, show small or no effect, or even contra-intuitive and adverse effects. In spite of a lot of effort, satisfactory understanding of this phenomenon has not, in the author's view, been reached. Several driver behaviour models have been launched during the years, the oldest one dating back to 1938 (Gibson and Crooks). Other models that have been widely discussed during the 2-3 last decades are, among others, Naeaetaenen and Summala's 'Zero-risk model' (1974), Wilde's 'Risk Homeostasis Theory (1982), Fuller's theory of 'Threat-Avoidance' (1986). No agreement has, however, been achieved concerning driver behaviour models and their ability to predict driver behaviour. Different models are heavily debated and key issues like the perception and monitoring of risk, and the mechanisms involved in information processing and decision making, are still under discussion. One key issue that in the author's view has been neglected for decades, is the role of the emotions. The observations made by Taylor (1964), concerning the constancy of the autonomic galvanic skin response (GSR) across a variety of roads and conditions, were integrated in Naeaetaenen and Summala's 'zero-risk theory proposing that '.... driving is a self-paced task governed by the level of emotional tension or anxiety which the drivers wishes to tolerate' (Taylor 1964, Naeaetaenen and Summala (1974). In the present paper, it is argued that more recent achievements in neurobiology can be applied to support the views propagated by Taylor and Naeaetaenen and Summala. In his book, Descartes' Error: Emotion, Reason and the Human Brain Damasio argues that a separation between neocortex, the structure believed to be responsible for conscious, rational thinking, reasoning, and decision-making, and the old structure of the brain, the limbic system, thought to be responsible for emotions and biological regulation of the body, is too crude and not in accordance with empirical observations. Damasio distinguishes between emotions, defined as bodily responses and changes caused by external stimuli, and feelings, defined as the conscious experiences of these bodily changes and argues that the emotions, and feelings, are the very instruments that make an organism capable of evaluating scenarios and making decisions in any given situation. The present paper discusses the model put forward by Damasio and its implications for understanding risk monitoring, processing of information and decision-making. (A) For the covering abstract of the conference see ITRD no 207828. The reprints are also available at the web - http://www.vti.se/pdf/reports/K18APart1.pdf; http://www.vti.se/pdf/reports/K18APart2.pdf and http://www.vti.se/pdf/reports/K18APart3.pdf.
Abstract