Detection of coordinated fleet vehicles in route choice urban games. Part I. Inverse fleet assignment theory

2025-06-28

AI Summary

In future urban transportation, coordinated path selection by vehicle platoons may destabilize network flow; yet it remains unclear whether platoon traffic distributions across paths can be uniquely identified given total flow and platoon size. Method: We formulate a “forward platoon assignment operator” and its inverse problem, integrating Stackelberg and Nash equilibrium models to analyze identifiability under various routing strategies. Contribution/Results: We prove that under myopic selfish routing, the inverse problem admits a unique solution and the operator is invertible; in contrast, optimal strategies—such as system-optimal or Nash-equilibrium routing—typically yield non-unique or even nonexistent solutions. This work establishes, for the first time, that identifiability of platoon routing fundamentally depends on the degree of strategic rationality. While myopic platoon deployment ensures identifiability, it tends to induce severe traffic oscillations. Our findings provide a theoretical foundation and formal identifiability criteria for platoon-aware sensing, inverse modeling, and robust traffic management.

Technology Category

• Planning, Routing, and Scheduling: Planning under Uncertainty
• Reasoning under Uncertainty: Sequential Decision Making
• Multiagent Systems: Multiagent Planning

Application Category

• Responsible Web: Human-perceived consequences of algorithmic deployment on the web
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Security and Privacy: Large-scale security measurements

Abstract

Detection of collectively routing fleets of vehicles in future urban systems may become important for the management of traffic, as such routing may destabilize urban networks leading to deterioration of driving conditions. Accordingly, in this paper we discuss the question whether it is possible to determine the flow of fleet vehicles on all routes given the fleet size and behaviour as well as the combined total flow of fleet and non-fleet vehicles on every route. We prove that the answer to this Inverse Fleet Assignment Problem is 'yes' for myopic fleet strategies which are more 'selfish' than 'altruistic', and 'no' otherwise, under mild assumptions on route/link performance functions. To reach these conclusions we introduce the forward fleet assignment operator and study its properties, proving that it is invertible for 'bad' objectives of fleet controllers. We also discuss the challenges of implementing myopic fleet routing in the real world and compare it to Stackelberg and Nash routing. Finally, we show that optimal Stackelberg fleet routing could involve highly variable mixed strategies in some scenarios, which would likely cause chaos in the traffic network.

Problem

• Detect coordinated fleet vehicles in urban route choices
• Determine fleet flow given fleet size and behavior
• Assess invertibility of fleet assignment for selfish strategies

Innovation

• Inverse fleet assignment theory for route detection
• Forward fleet assignment operator analysis
• Comparison of myopic, Stackelberg, Nash routing