An Algorithm for the Stochastic User Equilibrium Problem

Olof Damberg, Jan T. Lundgren and Michael Patriksson
Department of Mathematics
Linköping Institute of Technology
S-581 83 Linköping
Sweden

ABSTRACT:

In this paper we present a new algorithm for the approximate solution of the
logit-based stochastic user equilibrium problem. 
The main advantage of this algorithm is that
it provides route flows explicitly, of particular interest in the evaluation
of route guidance and information systems;
in previously proposed methods for the stochastic user equilibrium problem,
only link flows are provided.
The proposed algorithm alternates between two main phases. In the subproblem
phase, profitable routes are generated. In a restricted master problem, a
descent method is used to solve the restriction to the original problem to the
subset of the total set of routes generated so far.
We present and evaluate alternative strategies for generating routes
algorithmically, and discuss the possibility of utilizing such strategies for
reducing the inherent problem of overlapping route flows in logit-based
traffic models.