Failure of classical traffic and transportation theory: The maximization of the network throughput maintaining free flow conditions in network

TL;DR

This paper identifies physical conditions for maximizing network throughput while maintaining free flow, introduces a network capacity measure, and proves the limitations of classical traffic assignment methods like Wardrop's equilibria.

Contribution

It reveals fundamental physical conditions for maximizing network throughput and introduces a new measure called network capacity, challenging classical traffic theory assumptions.

Findings

Physical conditions for free flow network throughput maximization

Introduction of a network capacity measure

Classical traffic assignment methods can deteriorate system performance

Abstract

We have revealed general physical conditions for the {\it maximization} of the network throughput at which free flow conditions are ensured, i.e., traffic breakdown cannot occur in the whole traffic or transportation network. A physical measure of the network -- {\it network capacity} is introduced that characterizes general features of the network with respect to the maximization of the network throughput. The network capacity allows us also to make a general proof of the deterioration of traffic system occurring when dynamic traffic assignment is performed in a network based on the classical Wardrop' user equilibrium (UE) and system optimum (SO) equilibrium.