The Value of Information in Selfish Routing

Path selection by selfish agents has traditionally been studied by comparing social optima and equilibria in the Wardrop model, i.e., by investigating the Price of Anarchy in selfish routing. In this work, we refine and extend the traditional selfish-routing model in order to answer questions that arise in emerging path-aware Internet architectures. The model enables us to characterize the impact of different degrees of congestion information that users possess. Furthermore, it allows us to analytically quantify the impact of selfish routing, not only on users, but also on network operators. Based on our model, we show that the cost of selfish routing depends on the network topology, the perspective (users versus network operators), and the information that users have. Surprisingly, we show analytically and empirically that less information tends to lower the Price of Anarchy, almost to the optimum. Our results hence suggest that selfish routing has modest social cost even without the dissemination of path-load information.Comment: 27th International Colloquium on Structural Information and Communication Complexity (SIROCCO 2020

A retrospective on Beckmann, McGuire and Winsten's "Studies in the Economics of Transportation"

This article describes the impact and influence of the book, "Studies in the Economics of Transportation", by M. Beckmann, C.B. McGuire and C.B. Winsten, published in 1956 by Yale University Press. Our focus is on the book's impacts on innovations in modeling, methodological developments and applications in transportation, regional science and other disciplines, which continue to this day. Copyright RSAI 2005.

Routing on a Ring Network

International audienceWe study routing on a ring network in which traffic originates from nodes on the ring and is destined to the center. The users can take direct paths from originating nodes to the center and also multihop paths via other nodes. We show that routing games with only one and two hop paths and linear costs are potential games. We give explicit expressions of Nash equilibrium flows for networks with any generic cost function and symmetric loads. We also consider a ring network with random number of users at nodes, all of them having same demand, and linear routing costs. We give explicit characterization of Nash equilibria for two cases: (i) General i.i.d. loads and one and two hop paths, (ii) Bernoulli distributed loads. We also analyze optimal routing in each of these cases

Solving Congestion Toll Pricing Models

: Recently a methodology for traffic networks has been developed which extracts congestion toll sets such that the tolled user equilibrium is system optimal. Properties of toll sets, such as convexity, are investigated, as well as relationships with other problems. For a given toll set, various objectives can be defined and optimized with respect to the tolls. Examples include minimizing the total tolls collected, minimizing the number of toll booths and constraining net tolls collected to be zero. We illustrate with an example and report on our computational experience with the Stockholm network. 1.1 INTRODUCTION Congestion toll pricing addresses the classic traffic assignment problem for which Wardrop enunciated two principles of traffic flow: user-optimal behavioral hypothesis and the notion and system-optimality. (See [7] for a recent review of the traffic assignment problem and [12] for a recent volume of papers on road pricing.) The traditional objective of congestion pricing h..

Reaction Function Based Dynamic Location Modeling in Stackelberg–Nash–Cournot Competition

We formulate a dynamic facility location model for a firm locating on a discrete network. It is assumed that this locating firm will act as the leader firm in an industry characterized by Stackelberg leader–follower competition. The firm’s I competitors are assumed to act as Cournot firms and are each assumed to operate under the assumption of zero conjectural variation with respect to their I–1 Cournot competitors. Using sensitivity analysis of variational inequalities within a hierachical mathematical programming approach, we develop reaction function based dynamic models to optimize the Stackelberg firm’s location decision. In the second half of this paper, we use these models to illustrate through a numerical example the insights yielded by our approach. Copyright Springer Science+Business Media, LLC 2007Dynamic Stackelberg equilibrium location modeling, Reaction functions,