Universality in City Morphology and the Morphology of a City and its Implications for City Evacuation Plans

Street networks play a crucial role in the emergence of vehicular traffic. Here we present an experimental analysis of the street networks of several European cities (London, Paris, Rome, Modena). This analysis evidences the existence of universal properties in the morphology of different cities, which is captured by a model for the dynamics of city growth. Then, we discuss the implications of our findings for the development of city evacuation plans, whose efficiency is of paramount importance for cities threatened by natural hazards, such as volcanoes.