A latent class approach to dealing with respondent uncertainty in a stated choice survey for fare simplification on bus journeys

This article presents the findings of an analysis making use of a stated choice survey looking at bus travellers’ preferences for specific fare structures. Specifically, respondents were given the choice between the current fare structure, which is largely distance based, a fixed fare structure, and a zonal fare structure. It was anticipated that there might be two sources of substantial respondent uncertainty, in relation to the current fare as well as the number of zones a specific journey covers. These two types of uncertainty could create a significant level of bias in the results, and in this article, we put forward a modelling approach based on a latent class structure that allows us to accommodate this respondent uncertainty and avoid the source of bias. Latent class structures are used widely to allow for variations in sensitivities across individual decision makers; here, we show how such a structure is equally well suited to deal with respondent uncertainty expressed through variations in the perceived fares of different journey options.