A dynamic input-output model to project U.S. freight transportation demand

Abstract

Understanding and modeling U.S. freight transportation demand is essential for infrastructure planning, the development of transportation-related regulatory frameworks, and the assessment of environmental implications. However, existing models that forecast U.S. freight transportation demand are very complicated and require a vast computational effort. In the following, I develop a simpler, yet more effective, model to project economic performance and the resulting freight transportation demand. I analyze and project economic growth and structural change using an input-output framework. This economic part of my model projects U.S. commodity output values for the next two decades. In the second part of my model, commodity values are transformed into quantities of freight transportation demand. The latter are the basis for deriving environmental implications of growing freight shipment activities. In the analysis of model outputs, I examine a significant trend towards relatively light, high-value commodities, which reflects ongoing dematerialization in the U.S. economy. Nevertheless, these commodities promote a shift towards faster, more energy-intensive freight transport modes, which gives reason for environmental concern and requires regulatory action to support less carbon-intensive freight transportation.