Abstract
When social values change travel demand forecasting should adapt to those changes. In this paper I have argued that indeed there is such a change, and that it involves a shift from socio-economic factors towards psychological and lifestyle factors as trip determinants. Psychology can be an aid to travel demand analysis, but it apparently can only fulfil that role if it is also accepted as a guide at the same time. Consequently, the rhetorical question that served as the title of this contribution should be restated before it can be answered in the affirmative: psychology should be both aid and guide for travel demand analysis.