Introducing trip frequency: scientists add a new key component in human mobility studies

There is a new simple, robust, scaling law in the studies of human travel, that includes a component rarely considered in previous theories: visitation frequency, i.e. the number of trips that someone makes to a location per unit of time. In a new paper recently out in Nature, a team of researchers including former ISI affiliate Michael Szell suggests that the number of visitors to any location decreases as the inverse square of the product of their visiting frequency and travel distance.

Based on the analysis of mobile-phone tracking data in several urban systems around the globe, the study brings a great novelty in comparison with existing models – such as the gravity law or the radiation model – that concentrate on the purely spatial dependence of mobility flows and do not capture the varying frequencies of recurrent visits to the same locations.

Findings corroborate long-standing conjectures in human geography, scientists say, and allow for predictions of recurrent flows, providing a basis for applications in urban planning, traffic engineering and the mitigation of epidemic diseases.

“The universal visitation law of human mobility”, Markus Schläpfer, Lei Dong, Kevin O’Keeffe, Paolo Santi, Michael Szell, Hadrien Salat, Samuel Anklesaria, Mohammad Vazifeh, Carlo Ratti & Geoffrey B. West. Nature, 26th May 2021.