OVERTAKING AND UTILITY MAXIMIZATION: A MODELLING EXERCISE --ROAD USER BEHAVIOR. THEORY AND RESEARCH. PAPERS PRESENTED AT THE 2ND INTERNATIONAL CONFERENCE ON ROAD SAFETY HELD IN GRONINGEN, NETHERLANDS, AUGUST 1987

People undertake a trip because they expect some benefit - whether material or immaterial from it. In order to achieve that benefit costs must be made first. There is optimization in the sense that, given some predetermined benefit the less costs required the better. Preferably, the sum of costs and benefits should be at a maximum. Theorizing which recognizes the rationale of travelling as paraphrased here comes under the heading of utility maximization theory. Driver speed choice may be modelled by means of a utility maximization model, balancing expected travel costs and expected accident loss against profits to be made when the destination is reached. The model provides a description of the phenomena of partial and perfect risk compensation. At the operation level the model incorporates momentary deviations from the optimal speed as the impetus for correct behaviour. The model's implications in a special case are discussed in terms of behavioural changes, accident rates and the degree of risk compensation to be expected as a result of the introduction of the safety measures specified in that case. For the covering abstract of the conference see IRRD 815404.