A theoretical framework and methodology for characterising national urban systems on the basis of flows of people: Empirical evidence for France and Germany

In advanced economies, flows play an important part in connecting urban nodes. This paper sets up a framework for identifying and classifying the pattern of the urban systems from an interaction perspective. Three S-dimensions are proposed (that is, the strength of interaction, the symmetry of interaction and the structure of the network) and a set of indices that are important for characterising network configurations. Using the European long-distance mobility database (DATELINE), the framework is applied to examine the pattern of interaction between functional urban areas (FURs) in France and Germany. The analysis is carried out separately for three journey purposes: business, holiday and leisure. The results reveal that national urban systems embrace a wide variety of constellations and that considerable variation in these constellations can be observed across journey purposes and countries. Overall, the authors are confident that the proposed framework provides a useful analytical tool for characterising the configurations of urban systems.