In this paper, passenger willingness-to-pay (WTP) for improving the quality levels of a bus service is
examined. Specifically, the objective of this research is to provide a tool for evaluating passenger
willingness-to-pay by considering some qualitative service aspects, in addition to the traditional
quantitative service aspects like travel time and cost. The adopted methodology is built on the calibration
of behavioural models based on user choices. The WTP values are obtained as marginal rates of
substitution between some service quality attributes and travel cost at constant utility. For this purpose,
Multinomial and Mixed Logit models are introduced. The models were calibrated by using the data
collected from an SP experiment in which each user makes a choice between an alternative representing
the current service and two alternatives representing hypothetical bus services. In order to take into
account the randomness of the estimated WTP, the limits of the confidence intervals are calculated.
