Institute for Transport Studies (ITS)

Developments in experimental design for stated choice surveys and alternative preference elicitation procedures

Supervisors: Professor Stephane Hess, Dr Jeremy Toner

The analysis of travel behaviour requires as its main input data on travel decisions (choices) made by individual respondents. However, in many situations, data on real world choices is either not available or is not suitable for the purposes of the proposed analysis. As a result, an increasing number of studies rely on data collected through surveys which present respondents with hypothetical choice scenarios. Data from such stated preference (SP) surveys are used not only in academic work but also form the backbone of many studies advising policy makers in scenarios as wide ranging as the building of new roads, the introduction of road pricing or the investment in new rolling stock.

The majority of work using SP methods now makes use of stated choice (SC) surveys, in which respondents are asked to choose their most preferred option amongst a set of mutually exclusive alternatives. Approaches such as ranking or rating exercises have been largely discredited in a transport context, as have transfer price methods, which aim to directly obtain the willingness by respondents to pay for developments or improvements. However, outside a transport environment, these methods are experiencing a renaissance, and new developments, such as best-worst, a halfway measure between choice and full ranking, are gaining in popularity. At the same time, in transport and elsewhere, researchers are constantly devising new methods to improve the efficiency of the various available survey techniques. The net outcome is that there is substantial confusion at the user end, with practitioners often unsure which approach would be most applicable in their given context.

The aim of this PhD project would be to conduct an in depth comparison of the different available methods, highlighting which approaches are most adequate in what context. Additionally, the work would look at the potential for combining various existing methods. Finally, where appropriate, further methodological developments would be made.

Recommended reading:

Louviere, J.J., Hensher, D.A. and Swait, J.D. (2000) Stated Choice Methods: Analysis and Application. Cambridge University Press.

PTRC (2000) Stated Preference Modelling Techniques. A compilation of major papers from PTRC’s meeting and conference material. Edited by J de D Ortuzar. PTRC, London.

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