What determines patterns of human mobility flow

 

FILIPPO SIMINI

UNIVERSITÀ DEGLI STUDI DI PADOVA

 

The study of human mobility has drawn increasing interest in the last years, driven by the need for better urban planning, transportation design and epidemic control and by the data availability. Many of these applications are based on empirical laws like the gravity law, capable of fitting the data on commuting flows between pairs of locations in terms of few adjustable parameters which are context dependent. However a fundamental and robust modeling framework to explain the observed patterns has not yet been proposed. Here we present a simple model reflecting the human behaviour/attitude in the choice of trips within a whole country. The model capture the intrinsic stochastic nature of the trip choice, and the only needed input is the spatial population distribution of the country. The model predicts patterns of mobility flow which are statistically indistinguishable from the corresponding patterns as determined using three data-sets --the call records of cell-phone users and work-flows from US census 2000 and Portugal census 2001. This goes beyond the simple prediction of the commuting fluxes, which in the present approach are obtainable as expectation values. The probability distributions of the human mobility between pairs of locations, with given population, at a given distance are shown to depend only on a characteristic mobility flow scale and flow fluctuations are of the same order as the average flow itself.