Structure of urban movements: polycentric activity and entangled hierarchical flows

TL;DR

This study analyzes large-scale London subway data to uncover a polycentric urban structure with hierarchical and complex flow patterns, revealing how city centers are interconnected and how smaller flows contribute to the urban mobility network.

Contribution

It introduces a novel analysis of real-time mobility data to reveal the polycentric and hierarchical organization of urban flows, advancing understanding of city dynamics.

Findings

Urban movement patterns are highly heterogeneous in volume.

A polycentric structure with a limited number of major activity centers exists.

Smaller flows exhibit complex, non-hierarchical connection patterns.

Abstract

The spatial arrangement of urban hubs and centers and how individuals interact with these centers is a crucial problem with many applications ranging from urban planning to epidemiology. We utilize here in an unprecedented manner the large scale, real-time 'Oyster' card database of individual person movements in the London subway to reveal the structure and organization of the city. We show that patterns of intraurban movement are strongly heterogeneous in terms of volume, but not in terms of distance travelled, and that there is a polycentric structure composed of large flows organized around a limited number of activity centers. For smaller flows, the pattern of connections becomes richer and more complex and is not strictly hierarchical since it mixes different levels consisting of different orders of magnitude. This new understanding can shed light on the impact of new urban projects on the evolution of the polycentric configuration of a city and the dense structure of its centers and it provides an initial approach to modeling flows in an urban system.