Journal of Geography and Regional Planning Vol. 5(10), pp. 263-286, 18 May, 2012 Available online at http://www.academicjournals.org/JGRP DOI: 10.5897/JGRP12.008 ISSN 2070-1845 ©2012 Academic Journals Full Length Research Paper Exploration and visualization of highway freight flow movements in the United States using Geographical Information System (GIS) Guoqiang Shen 1 * and S. Gizem Aydin 2 1 Division of Regional and City Planning, College of Architecture, University of Oklahoma 830 Van Vleet Oval, Norman, OK 73019, United States of America. 2 School of Industrial Engineering, University of Oklahoma, Carson Engineering Center, 202 W. Boyd St. Room 448C, Norman, OK 73069,United States of America. Accepted 13 March, 2012 This paper begins with a concise national overview of the transported goods, classified by Standard Classification of Transport Goods, and their movements on the highway networks in the United States using TransCAD, a geographical information system with strong transportation planning capabilities and the freight analysis framework database version 2.2 or FAF 2.2 . Then, the paper constructs more national views of from, to, within, and through freight flows for the 50 U.S. states and DC to highlight the spatial patterns of total freight flows by state. The local views of total freight flows focus on Oklahoma, the so called “cross-road” state of America. A linear regression model is established by linking state freight flows to state major socio-economic indicators, such as employment, revenue, income, and payroll for the year 2002. State total freight flows in tonnage or by commodity are calculated to reveal top or bottom states in handling from, to, within, and through freight flows. Key words: Highway, freight, flow, regression, geographical information system (GIS), visualization. INTRODUCTION Freight transportation is an important aspect of transportation and is essential to the national and local economy. Today, most consumable goods worldwide are transported on multi-modal networks involving waterways, railways, highways, and airways to their demand markets, such as cities, distribution centers, or retail stores, and finally to the consumers. Freight is also an important factor for transportation decisions and policies on infrastructure, investment, safety, and security. Various transportation policies have been formed and implemented based on freight research. Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 requires all Metropolitan Planning Organizations (MPOs) and other regional or local planning agencies to include freight transportation issues in state and *Corresponding author. E-mail: guoqiangs@ou.edu. Tel: 405- 325-1698. metropolitan transportation plans (Siwek, 1996). This requirement was further continued with the Transportation Equity Act for the 21st Century (TEA-21) and the Safe, Accountable, Flexible, Efficient Transportation Equity Act (SAFETEA-LU) of 2005 (FHWA, 2005; 2010, 2011). Freight movement can be realized by single mode (i.e., by waterway) or multi-mode (i.e., by railway and highway) transportation from an origin to a destination. However, most import and export freight are often moved by multi- mode involving water, rail, and truck. Multi-mode freight is processed at inter-modal facilities where one mode is transferred to another. For example, the freight from Shanghai, China may enter Los Angeles or Long Beach ports by ocean waterways, then is loaded on a rail to an inland city (that is, Fort Worth, TX), and is finally trucked to its final destination (i.e., Oklahoma City). Freight movement is often analyzed at a spatial scale, which, for this study, is at the state level. Freight coming into a state is named “to freight” or “freight attraction”,