Best Practice in SP Design
N Sanko, Ecole Nationale des Ponts et Chaussees, FR;
Stated Preference surveys have now been used for up to twenty years for looking at transport policy issues and a number of schools of practice have developed. Within each school, practitioners improve their methodology but they rarely if ever take account of developments in competing schools. The result is that particular aspects of SP practice are done better in one school than another.
A key stage in conducting an SP study is the experimental design of the survey; this is also one of the areas where there are substantial differences of approach between the schools. A researcher trying to set up a study is therefore faced with a series of practical issues and can have great difficulty in finding his or her way through the jungle of the literature.
The paper reports the findings of a study conducted by RAND Europe to look at the state of practice in experimental design for SP surveys. Comparing the methods used by different schools - in the US, Australia and Japan, as well as in Europe - practical conclusions are drawn as to the best procedures tofollow in the present state of understanding of design procedures. Areas are identified where research is clearly necessary, but in many cases it is possible to make clear recommendations.
The original aspect of the paper, other than comparing the work of the competing SP schools, is in deriving practical step-by-step procedures for choosing the best available design for a given survey.
Association for European Transport