Traffic-driven multi-epidemic spreading in complex networks

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.