While the volumes hitherto published in the Springer Series in Synergetics have been devoted almost exclusively to the self-organized formation of structures in physics, chemistry and biology, the present monograph by Weidlich and Haag deals with the formation of "structures" (or "patterns") in society. At first glance it would seem a daring enterprise to deal with the complex processes in society using concepts and methods first developed in physics. But over the past decade it has been shown that there is a large class of phenomena in a variety of fields to which unifying concepts can be applied. This is particulary true of situations in which a system composed of many parts or individuals acquires a new structure on macroscopic scales. Indeed, this is the definition of synergetics which I formulated more than a decade ago, and which formed the basis of my survey on the profound analogies in the behaviour of complex systems, includ ing those of sociology (H. Haken: Synergetics. An Introduction, Volume 1 of this series). As I have pointed out on many occasions, the universal validity of these concepts is neither accidental nor is it caused by a mere extension of physical rules to other fields, but is instead a consequence of deep-rooted struc tural properties of systems of interacting parts which are due to rigorous mathe maticallaws. Generally speaking, concepts and methods originally used in physics can be applied to sociological phenomena in two ways."

Gone are the days when mobility was nearly always a question of having a vehicle. Today the issue of road capacity is becoming ever more pressing. Even the safest, most comfortable and 100% emissions-free vehicle is only of limited use if it is stuck in a traffic jam. Mobility is a key human need and an important factor in the economy. It is a matter of logic that a com pany like DaimlerChrysler should make every endeavor to safeguard mo bility, thereby fulfilling humanity's economic, social and environmental needs. Nonetheless, traffic and mobility problems are the inevitable result of a concentration of people and markets. Bombay, Lagos, Shanghai, Jakarta, Sao Paulo, Cairo, Mexico City - virtually half of the world's population is urban-based, and the majority live in the metropolitan regions of the Third World. The mega-cities in the so-called developing nations are facing a dramatic increase in traffic levels. Gridlock looms on the horizon. Should traffic-choked streets become a permanent and daily occurrence, economic development will be held in check and pollution will spiral."