Inefficiency of Logit-Based Stochastic User Equilibrium in a Traffic Network Under ATIS

Abstract

This paper makes a contribution to the literature by bounding the travel time inefficiency of the logit-based stochastic user equilibrium (SUE) under Advanced Traveler Information Systems (ATIS). All drivers are divided into two groups, one equipped with ATIS and another without, and both of which follow the logit-based SUE principle in making route choices. The equipped drivers have less degree of travel time variability than the unequipped ones. The inefficiency of the two-user class SUE is defined in two different ways, i.e., in comparison with the SO in terms of total actual system travel time, or in comparison with the corresponding SSO in terms of total perceptive system travel time of all users. The effects of various parameters on the bounds are further investigated. It is found that the inefficiency bound against the SSO is only dependent upon the degree of link congestion and independent of the network topology. In contrast, besides the effect of the degree of link congestion, the increasing of total demand and network complexity will also make the inefficiency bound against the SO go up, while the promotion of ATIS market penetration and perception benefit will reduce the bound.