Traffic-driven multi-epidemic spreading in complex networks

¹ School of Traffic and Transportation, Shijiazhuang Tiedao University - Shijiazhuang 050043, PRC
² Jiyuan Vocational and Technical College - Jiyuan 459000, PRC
³ School of Computer and Information, Anhui Normal University - Wuhu 241003, PRC
⁴ School of Engineering Science, University of Science and Technology of China - Hefei 230026, PRC
⁵ Department of Engineering Mechanics, Shijiazhuang Tiedao University - Shijiazhuang 050043, PRC

Received: 31 July 2025
Accepted: 1 October 2025

Abstract

While extensive research has explored traffic-driven epidemic spreading, the co-evolution of interdependent epidemics —where one dynamically regulates the spreading of the other— remains uncharted territory. Through integrating theoretical analysis with network-based traffic dynamics, we reveal distinct epidemic thresholds governed by traffic states and interaction mechanisms. In free-flow regimes, the epidemic threshold of epidemic B is dynamically modulated by the spread of epidemic A, exhibiting suppression-induced elevation or synergy-driven reduction contingent on the spread scope of epidemic A and the parameter α. During congestion phases, traffic load systematically amplifies epidemic spreading below critical traffic levels, while crossing this threshold triggers cooperative or competitive interactions contingent on coupling mechanisms. These findings elucidate how the interplay between traffic dynamics and epidemic interdependencies governs spreading thresholds, offering a framework for designing adaptive containment strategies in networked systems.