Solution Algorithms for Stochastic Dynamic User-Optimal Route Choice Models

Abstract

Chapter 8 described two logit-type SDUO route choice models which are stochastic generalizations of deterministic dynamic user-optimal route choice models previously presented in Chapters 5 and 7. To solve these models for large networks, we need to develop solution algorithms avoiding route enumeration. Thus, the stochastic dynamic network algorithms in this chapter are link-based procedures that avoid route enumeration and perform dynamic assignments using only link and node variables. Some new notation is presented in Section 9.1. In Sections 9.2 and 9.3, two multiple-route dynamic route choice algorithms (DYNASTOCH) similar to Dial’s efficient-route algorithm (STOCH) are suggested to solve two discrete-time flow-independent instantaneous and ideal SDUO route choice models. Then, the discrete formulation of the flowdependent instantaneous SDUO route choice model is presented in Section 9.4 and a solution algorithm is presented to solve this model. In Section 9.5, the discrete formulation of ideal SDUO route choice model is presented and a solution algorithm is also proposed. In both solution algorithms for the flow-dependent SDUO route choice models, the DYNASTOCH algorithms are used to solve their subproblems so that explicit route enumeration can be avoided. The method of successive averages (MSA) and other methods are suggested to solve the one-dimensional search problems. Numerical examples are presented in Section 9.6 to illustrate the solution of the proposed algorithms.