An integrated behavioral model of the land-use and transport systems with network congestion and location externalities

The agents' decisions, from their residential location to their members' trip choices through the network, are jointly analyzed as an integrated long term equilibrium in which the location, travel decisions, and route choices are represented by logit or entropy models. In this approach, consumers optimize their combined residence and transport options represented as paths in an extended network built by connecting the transport sub-network to a fictitious sub-network that represents land-use and transport demand options. We model a static land-use and transport equilibrium by considering road congestion and location externalities. The latter include trip destination choices based on land-use attractions, as well as endogenous neighborhood characteristics that determine residential choices and segregation phenomena. The model can deal with heterogeneous populations and locations as well as multiple trip purposes, though it assumes only private transport modes. In a previous paper we studied the case with road congestion externalities only, characterizing equilibria by a strictly convex and coercive unconstrained minimization problem. This characterization fails for more general externalities, so we restate the model as a fixed-point problem, establishing the existence of equilibria, providing sufficient conditions for its uniqueness and for the convergence of a fixed-point iteration. A small numerical example is used to illustrate the model. (C) 2009 Elsevier Ltd. All rights reserved.