Abstract
This paper considers the relationship between transport information systems and the individual choices made. In particular the following are studied: a) the relationship between the accuracy of the information system and the probability of individual discrete choices, b) measurement and the value of the information system and c) estimation of the parameters of individual behaviour and the information system as a whole system. A new model is described which can measure the effects of the information system by a combination of the decision theory under uncertainty and the logit model based on the probabilistic utility theory. The model is described and its validation using stated preference interviews outlined.