Modal freight transport required for production of US goods and services Rachael Nealer ⇑ , Christopher L. Weber, Chris Hendrickson, H. Scott Matthews Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, United States article info Article history: Received 28 May 2010 Received in revised form 29 September 2010 Accepted 31 October 2010 Keywords: Freight movement Commodity flow Modal freight transportation Supply chain Input–output analysis abstract In this paper we develop a model which approximates the upstream supply chains for embodied transportation in products. The sector with the largest embodied freight trans- portation in consumption is petroleum products followed by government services, con- struction, and food products. Overall, pipeline contributes 7% to the total embodied freight movement per sector, air transport is generally under 1%, water is 5%, and rail and truck transportation are the most dominant modes (14% each) for domestic freight transportation for the average sector. International water is the largest mode (60%) even compared to domestic modes, and international air contributes less than 1%. Ó 2010 Published by Elsevier Ltd. 1. Introduction Transportation is ubiquitous in the supply chain of goods and services, in the shipment of intermediate inputs, as well as in the delivery of final goods. For example, in the case of automobiles, glass is shipped to windshield manufacturers, wind- shields are shipped to auto manufacturers, and autos are shipped to dealers where consumers buy them. Knowing the embodied transportation needed for the manufacturing and distribution of each product is useful when considering issues such as fuel cost changes, traffic congestion, and resiliency and security of the various modes of transportation (Smith et al., 2005). Over the past decades, supply chains and the logistics networks supporting them have become more global, faster, more complex, and more important in the US economy (US DOT, 2010; Meixell and Gargeya, 2005). Broad-scale develop- ments in information and communications technology (ICT) and micro-scale management of businesses (such as just- in-time manufacturing) have increased the visibility and importance of logistics in the world economy (Womack et al., 1990; Klassen, 2000). At the same time, growing awareness of environmental issues such as climate change and air quality has made it more important that these increasingly intensive activities are performed in a sustainable way. Since transpor- tation contributes to 33% of US CO 2 emissions and large portions of several criteria air pollutants (58% of NO X , 36% of VOCs, and 77% of CO), it is clearly important in efforts to promote environmental sustainability and green supply chain manage- ment (US EPA, 2004; Sheu et al., 2004). Transportation also represents a major investment of public funds, with over $45 billion invested in transportation infrastructure by the federal government in 2006 and a comparable amount by state and local agencies (CBO, 2007). Understanding the preferred methods of transportation, amounts of commodities shipped, and kinds of commodities shipped can provide insight into the resiliency of the transportation system and project future infrastructure improvements necessary to create more reliable and efficient methods of transportation. International transportation of both goods and people deserves particular mention. International freight transportation to the US (in ton-km) was approximately equal 1366-5545/$ - see front matter Ó 2010 Published by Elsevier Ltd. doi:10.1016/j.tre.2010.11.015 ⇑ Corresponding author. Address: 5000 Forbes Ave., 115 Porter Hall, Pittsburgh, PA 15213, United States. Tel.: +1 412 268 2940; fax: +1 412 268 781. E-mail address: rnealer@gmail.com (R. Nealer). Transportation Research Part E 47 (2011) 474–489 Contents lists available at ScienceDirect Transportation Research Part E journal homepage: www.elsevier.com/locate/tre