Analytical Problems in Linking an Activity Model with a Transportation Network Model

Abstract

Various approaches are considered for linking an activity model with a transportation network model. To explore the underlying analytical properties of the linking mechanisms, a prototype model is considered that has a simplified iterative generation–allocation model of the Garin–Lowry type for the activity component, and a trip assignment model for the transportation component. It is seen that there is an inconsistency with regard to activity behaviour under varying travel conditions, that there is no unique steady-state solution, and that the structural parameters are endogenous rather than exogenous to the model.