| A model of interregional commodity flows, incorporating regional input-output relationships, and the corresponding transportation network flows is formulated and implemented for assessing the economic impacts from an unexpected event. The Integrated Commodity Flow Model (ICFM) integrates a transportation network model with a regional input-output model. The model simultaneously forecasts commodity flow generation, distribution, mode choice, and assignment in a single procedure. The mode choice model forecasts mode share rates using the binary logit model. The model considers both interregional commodity flows and transportation network flows for 13 commodity sectors and two transportation modes for the United States. The model is solved with commodity flow data and transportation networks for the United States using Evans' partial linearization algorithm with Wilson's iterative balancing method. The performance of the model is investigated with regard to parameter estimation, convergence of the solution, and the validity of commodity flow results. Finally, the economic impacts of a catastrophic earthquake are estimated and evaluated by analyzing changes of objective function values, mean shipment distances and commodity flows based on hypothetical scenarios of unexpected events. |
