Reappraising our data sources for value of travel time estimation

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Abstract

The value of travel time (VTT) is often said to be the single most important input used in transport appraisal. Over the last three decades, a substantial body of academic work has improved the analytic toolkit used for deriving these valuations, looking both at the development of more advanced choice modelling approaches as well as non-parametric techniques. While much of the early work on VTT made use of revealed preference (RP) data, since the 1990s, there has been a reliance on stated preference (SP) for such analyses. This presentation re-evaluates the strengths and weaknesses of these two sources of information in the context of new emerging types of real-world data. We show how reliable VTT measures can be obtained using data collected via GPS tracking in the United Kingdom and mobile phone call detail record data from Senegal. Rather than seeking to seeking to replace SP by RP for VTT studies, the presentation then focusses on how future studies can benefit from the strengths of both types of data, while at the same time reducing the risk of behavioural incongruence from SP studies and mitigating the impact of data errors and gaps in automatically collected RP data.

Biography

Stephane Hess is Professor of Choice Modelling and Director of the Choice Modelling Centre at the University of Leeds, where he is based in the Institute for Transport Studies. He is also a part-time Professor of Decision modeling, artificial intelligence (AI) and mobility research at Delft University of Technology. He is Honorary Professor in Choice Modelling in the Institute for Transport and Logistics Studies at the University of Sydney and Honorary Professor of Modelling Behaviour in Africa at the University of Cape Town. Hess is an internationally recognised expert in the data driven study and mathematical modelling of human choice behaviour. He has made contributions to the state of the art in the specification, estimation and interpretation of such models, as well as in facilitating the transition of ideas and approaches across disciplines, notably by also working in mathematical psychology and behavioural economics. Although a majority of his applied work has been conducted in the field of transport, he is also very active in health and environmental economics. Together with David Palma, he is the author of Apollo, a highly flexible and powerful free tool for estimating and applying choice models.