Transportation involves a large number of complex and interacting relationships that are often difficult to analyze. Modelling involves the simplification and abstraction of the underlying, key relationships that assist this analysis. To this end, the last 40 years of the 20th century have witnessed the development and application of a large number of techniques and procedures directed towards enhancing our understanding of the behaviour of the various agents who impact on transport systems. The toolkit now available to transport modellers has evolved from many disciplines, most notably economics, engineering, psychology, geography and statistics with the focus on studying the behaviour of individuals and groups. The dominating theme of this volume on transport modelling is the study of the behaviour of individuals and organizations and the ways in which these affect the movement of persons, commodities or information.