The Rules of the Game.

In formulating travel demand models for planning studies, it is natural to expect that certain rules will apply to the formulation of the 'utility'functions that appear: price must have a negative coefficient, for example. But the issue of what other rules can or should be maintained is not atall clear: should the price variable be linear? should it be uniform across the travel alternatives? etc.. Most particularly, what goes wrong if the rules are broken? The presentation will clarify a number of the issues and lead to a discussion of what should be done in practice. A paper associated with the presentation goes into these issues in much more detail and precision. For the covering abstract see ITRD E135582.