'l'he papers contained in this volume were originally presented at the International symposium on New Directions in Urban Systems Modelling held at the University of Waterloo in July, 1983. The papers have been reviewed and rewritten since that time. The exception is the introductory paper written specially by Manfred Fischer and Peter Nijkamp as an introduction to this volume. The manuscript was prepared in the word processing unit in the nepartment of Civil Engineering, university of Waterloo. The sustained work of Mrs. I. Steffler in preparing this manuscript is gratefully acknowledged....