Futility of being selfish in optimized traffic

Optimizing traffic flow is essential for easing congestion. However, even when globally optimal, coordinated, and individualized routes are provided, users may choose alternative which offer lower individual costs. By analyzing the impact of selfish route choices on performance using cavity method, we find that a small ratio improves global uncoordinated transportation networks but degrades efficiency optimized systems. Remarkably, compliant always gain in former latter, under some parameter conditions. The theoretical results good agreement with large-scale simulations. Iterative switching by fraction leads to Nash equilibria close optimal routing solution. Our framework also generalizes use originally developed study equilibrium states, analyze iterative game-theoretical problems. These shed light feasibility congestion coordination not all vehicles follow coordinated routes.