ABSTRACT
The third millennium will be urban. Today, almost 50% of the world's population is urban. Forty years of exceptional demographic change have had impacts upon the features of cities all over the world. Thi phenomenon has specific manifestations over the five continents in terms of population concentration, the density of buildings, economic activities and services, transportation development and traffic flows, etc. But what are the similarities between Atlanta and Calcutta, Florence and Bamako? Do cities have the same cognitive representation, the same reality? Do cities share similar historical heritages or growth trends?
