Origin of the Scaling Law in Human Mobility: Hierarchical Organization of Traffic Systems

TL;DR

This paper introduces a hierarchical geographical model that explains the origin of the power-law scaling law in human mobility, aligning well with empirical data and highlighting the role of city organization.

Contribution

The study presents a novel hierarchical traffic system model that reproduces observed human mobility patterns, including power-law distributions and scaling behaviors.

Findings

Model reproduces power-law displacement distribution with exponent -2

Inhomogeneities lead to exponential cutoff in distribution

Results align with empirical human mobility data

Abstract

Uncovering the mechanism leading to the scaling law in human trajectories is of fundamental importance in understanding many spatiotemporal phenomena. We propose a hierarchical geographical model to mimic the real traffic system, upon which a random walker will generate a power-law travel displacement distribution with exponent -2. When considering the inhomogeneities of cities' locations and attractions, this model reproduces a power-law displacement distribution with an exponential cutoff, as well as a scaling behavior in the probability density of having traveled a certain distance at a certain time. Our results agree very well with the empirical observations reported in [D. Brockmann et al., Nature 439, 462 (2006)].