Abstract
This paper considers how road safety measures can influence driving behaviour. Ajzen's `Model of Planned Behaviour' is applied to traffic behaviour and an extension to the model suggested. The `Theory of Reasoned Action' is outlined. The importance of a) subjective norms, b) weighing attitudes and norms, c) subjective safety, d) controlability and e) the role of past experience are discussed. Examples of traffic related behaviour are given to support various aspects of the model. The model is then applied to a hypothetical safety measure in order to illustrate the steps taken in analysing its effects.