A MORE GENERAL MODEL OF INDIVIDUAL DEPARTURE TIME CHOICE --TRANSPORTATION PLANNING METHODS. PROCEEDINGS OF SEMINAR C HELD AT THE PTRC SUMMER ANNUAL MEETING, BATH UNIVERSITY ENGLAND, 7-11 SEPTEMBER 1987, VOLUME P290

Abstract

A more general model of individual departure time choice based on notions of utility theory. The empirical evidence on travel time variability indicates that the patterns of day-to-day and intra-peak variability are relatively straightforward to describe in statistical terms and display a high degree of uniformity across a wide variety of modal and urban settings. The recognition of travel time variability effects means that travel choices must be treated as choices amongst distributions of outcomes. Thus, departure time choices in conditions of variable travel time correspond to choices amongst distributions of outcomes such as the actual travel time and the lateness or earliness of arrival at the destination. Travellers will allocate a time for a journey which represents a balancing of these uncertain outcomes. The effective travel time which a traveller allocates for a journey may well be different (and is typically greater) than the expected travel time. The paper develops models of individual departure time choice in which uni-dimensional utility theory is employed to provide a consistent framework for modelling travel demand under uncertainty. The paper explores the properties of these models and shows that they represent a generalisation of a number of existing approaches in the literature.(a) for the covering abstract of the seminar see IRRD 816404.