Implementation and estimation of a combined model of interregional, multimodal commodity shipments and transportation network flows

A combined model of interregional, multimodal commodity shipments, incorporating regional input-output relationships, and the associated transportation network flows is formulated as an alternative to the traditional four-step travel forecasting procedure of trip generation, distribution, mode choice, and assignment. The paper describes the formulation of the model, its solution using US interregional commodity shipment data, estimation of key parameters, and evaluation of the performance of the model with the observed data. The model was implemented to predict interregional commodity shipments by roads and railways among regions of the US when these networks were disrupted by earthquakes or other natural events.