Comparing values of travel time obtained from residential, workplace and short-term decisions

Abstract

The value of travel time (VTT) is an important element cost-benefit analysis of transportation projects, by encapsulating the willingness to pay of the population for improvements in the transport system. Those values are typically obtained from mobility behaviour data, in form of revealed or stated preference survey data. Although short-term decisions are typically used for this purpose, a growing number of authors is arguing that long-term decisions might provide more meaningful values for the evaluation of transportation projects, as those decisions have a longer-lasting effect on the experienced travel times. This paper uses data, which contains both, short- and long-term experiments, to investigate the impact of different time horizons on the valuation of time. In particular, two different long-term experiments (residential and workplace choice) in the dataset allow to evaluate not only the impact of the time horizon, but also the type of long-term decision. Using a joint model including all relevant choice situations, this paper investigates the difference in the valuation of time coming from different kind of choice experiments. The results show that the chosen time horizon does have a significant effect on the valuation of travel time and cost. Another finding is that the type of long-term decision and the structure of the choice experiment itself also influence the valuation. The resulting VTTs with a sharp decline by about a half for commute trips show an opposite effect to previous work. Thus this paper demonstrates the need for refinement of the definition of such a VTT.