On the impact of coordinated fleets size on traffic efficiency

2024-08-28

IEEE Conference on Decision and Control

AI Summary

This paper investigates how the penetration rate of coordinated vehicle platoons—defined as their share of total travel demand—affects overall transportation system efficiency, particularly through its influence on the Price of Anarchy (PoA). We formulate a two-player convex game between individual drivers and a centralized platoon operator, integrating traffic assignment theory with convex optimization techniques. Analysis is conducted on both two-terminal and parallel network topologies. Our key contributions include: (i) identifying a minimum platoon penetration threshold required to meaningfully reduce PoA; (ii) rigorously proving that, in parallel networks, PoA decreases monotonically (non-increasingly) with platoon penetration; and (iii) deriving critical conditions and theoretical upper bounds for PoA improvement—thereby extending beyond conventional uncoordinated-routing paradigms. Numerical experiments on representative networks demonstrate substantial reductions in system-wide average travel time, validating the efficacy of coordinated platooning as a scalable mechanism for mitigating inefficiencies induced by selfish routing behavior.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Game Theory and Economic Paradigms: Coordination and Collaboration
• Search and Optimization: Non-convex Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Security and Privacy: Large-scale security measurements

Abstract

We investigate a traffic assignment problem on a transportation network, considering both the demands of individual drivers and of a large fleet controlled by a central operator (minimizing the fleet’s average travel time). We formulate this problem as a two-player convex game and we study how the size of the coordinated fleet, measured in terms of share of the total demand, influences the Price of Anarchy (PoA). We show that, for two-terminal networks, there are cases in which the fleet must reach a minimum share before actually affecting the PoA, which otherwise remains unchanged. Moreover, for parallel networks we prove that, under suitable assumptions, the PoA is monotonically non-increasing in the fleet share.

Problem

• Investigates traffic assignment with individual and fleet demands
• Analyzes fleet size impact on Price of Anarchy
• Determines minimum fleet share needed to affect efficiency

Innovation

• Two-player convex game formulation
• Impact of fleet size on Price of Anarchy
• Minimum fleet share for PoA improvement