Freight Flow Modeling in the United States

Abstract

This paper overviews the different approaches being used by regional planning agencies to estimate the spatial patterns of freight flows within the United States. The narrative moves from a discussion of current modeling practice to consider how on-going research efforts are moving this practice towards new, improved and increasingly involved modeling frameworks. The discussion emphasizes how data limitations have impacted past and current modeling, and how new data sources can help future efforts. Recent advances in both top-down econometric modeling and bottom-up behavioral modeling are described, both capable of contributing to increasingly complex modeling frameworks in support of broad regional and high volume freight corridor applications. How effective future modeling practice will become will depend on its ability to respond to three areas of concern: the need for improved data quality and access; an improved behavioral understanding of freight agents’ transportation choices; and changes in the nature of freight handling technologies and services as well as in the physical nature of the freight itself.