Evidence on the distribution of values of travel time savings from a six-week diary

Abstract

This paper presents the results of a series of mixed logit models focusing on the distribution of the values of travel time savings. The parametric assumptions include both normal and various bounded distributions derived from the normal (log-normal, Johnson's Sb and a censored normal). The full model, which also incorporates a number of time budget related variables, indicates that a small, but relevant share of the respondents might not value time savings, or would rather extend the journey. This share is consistent with results from other studies. A series of models for the different types of tours indicate even higher potential shares in situations with typically fewer binding time constraints. The RP data used is derived from the six week travel diary Mobidrive. The observations from Karlsruhe are summarised at the level of the tour.