  In this paper we deal with the study of travel flows and patterns of people
in large populated areas. Information about the movements of people is
extracted from coarse-grained aggregated cellular network data without tracking
mobile devices individually. Mobile phone data are provided by the Italian
telecommunication company TIM and consist of density profiles (i.e. the spatial
distribution) of people in a given area at various instants of time. By
computing a suitable approximation of the Wasserstein distance between two
consecutive density profiles, we are able to extract the main directions
followed by people, i.e. to understand how the mass of people distribute in
space and time. The main applications of the proposed technique are the
monitoring of daily flows of commuters, the organization of large events, and,
more in general, the traffic management and control.
