Abstract
One way of studying someone's travel behaviour has been the analysis of his individual trips, linked as they are from real origin to real destination. Another way, still under development, is studying the total trip pattern of a person over the whole day, a lot of trips being interdependent. This article means to give a general orientation towards the history of the models concerned and to draw a picture of future developments. Not only factors related to the individuals should be taken into account, but also variables concerning the community as a whole.