ABSTRACT
Psychophysiological techniques have been applied to the study of driving behaviour for over twenty-five years. The rationale behind this particular technique is rooted in the Yerkes-Dodson model which describes the relationship between performance and arousal (Yerkes and Dodson, 1908). According to the Yerkes-Dodson model, optimal task performance is achieved when the human evokes an optimal ‘quantity’ of Psychophysiological arousal. Any deviation above or below this Psychophysiological ‘ideal’ results in a decline of human performance. If arousal rises above the optimal level, performance deteriorates due to the operator being overloaded or under stress. Conversely if arousal falls below the optimal, the operator becomes bored and/or fatigued resulting in a similar decline in task performance. It does not take a great deal of imagination to see the implications of this model within the context of driving behaviour. The decline of driving performance due to the influence of Psychophysiological arousal was characterized by Wildervanck et al. (1978) in terms of different traffic environments. These authors assumed that monotonous highway driving deteriorated due to boredom or ‘underload’, whereas busy town driving declined due to stress or ‘overload’.
