A Simple Contagion Process Describes Spreading of Traffic Jams in Urban Networks

Congratulations to Dr Meead Saberi and his team for the recently published article, “A simple contagion process describes spreading of traffic jams in urban networks”  in Nature Communications. Authors include: Meead Saberi (rCITI UNSW),  Homayoun Hamedmoghadam (Monash Uni), Mudabber Ashfaq (rCITI UNSW), Seyed Amir Hosseini (K. N. Toosi Uni),  Ziyuan Gu (rCITI UNSW),  Sajjad Shafiei (Data61), Divya J. Nair (rCITI UNSW),  Vinayak Dixit (rCITI UNSW), Lauren Gardner (John Hopkins), S. Travis Waller (rCITI UNSW), & Marta C. González (UBerkley)

This study presents a framework describing the dynamics of congestion propagation and dissipation of traffic in cities using a simple contagion process, inspired by those used to model infectious disease spread in a population. We introduce two macroscopic characteristics for network traffic dynamics, namely congestion propagation rate β and congestion dissipation rate μ. We describe the dynamics of congestion spread using these new parameters embedded within a system of ordinary differential equations, similar to the well-known susceptible-infected-recovered (SIR) model.

The spread of traffic jams in urban networks has long been viewed as a complex spatio-temporal phenomenon that often requires computationally intensive microscopic models for analysis purposes.

The proposed contagion-based dynamics are verified through an empirical multi-city analysis, and can be used to monitor, predict and control the fraction of congested links in the network over time.