Assessing the energy and greenhouse gas emissions mitigation effectiveness of potential US modal freight policies Rachael Nealer ⇑ , H. Scott Matthews, Chris Hendrickson Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, United States article info Article history: Received 29 April 2011 Received in revised form 14 November 2011 Accepted 29 November 2011 Keywords: Freight movement policy Energy and emissions Modal choice Supply chain Input–output analysis abstract This paper estimates the total embodied energy and emissions modal freight requirements across the supply chain for each of over 400 sectors using Bureau of Transportation Statis- tics Commodity Flow Survey data and Bureau of Economic Analysis economic input–output tables for 2002. Across all sectors, direct domestic truck and rail transportation are similar in magnitude for embodied freight transportation of goods and services in terms of ton-km. However, the sectors differ significantly in energy consumption, greenhouse gas emissions, and costs per ton-km. Recent pressure to reduce energy consumption and emissions has motivated a search for more efficient freight mode choices. One solution would be to shift freight transportation away from modes that require more energy and emit more (e.g., truck) to modes that consume and emit less (e.g., rail and water). Our results show there are no individual sectors for which targeting changes would sig- nificantly decrease the total freight transportation energy and emissions, therefore we have also looked at the prospect of policies encouraging many sectors to shift modes. There are four scenarios analyzed: (1) shifting all truck to rail, shifting top 20% sector mode choice, (2) based on their emissions, (3) based on a multi-attribute analysis, and (4) increasing truck efficiency (e.g., mpg). Increasing truck efficiency by 10% results in similar energy and emis- sions reductions (approximately 7% for energy and 6% for emissions) as targeting the top 20% of sectors when selected based on emissions, whereas selecting the top 20% based on availability to shift from truck results in slightly less reductions of energy and emissions. Implementing policies to encourage higher efficiency in freight trucks may be a sufficient short term goal while efforts to reduce truck freight transportation through sectoral policies are implemented in the long term. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction The transportation sector, including freight and passenger movement, is responsible for a large portion of US annual en- ergy and emissions; approximately 30% of US energy and 33% of US carbon dioxide (CO 2 ) emissions. With energy consump- tion and emissions becoming a national issue, knowing the embodied freight transportation for each product is useful for considering how to reduce energy and emissions (Smith et al., 2005). Transportation also represents billions of dollars per year in investment by local, state, and federal agencies (CBO, 2007). Freight transportation, a portion of total US trans- portation energy and emissions (approximately 30%), is embodied in the supply chain of all goods and services (EIA, 1999; FHWA, 2005). For example, when manufacturing an automobile, glass is shipped to the windshield manufacturer, wind- shields are shipped to the automobile manufacturer, and the final product of the vehicle is shipped to the sales lots. The freight transportation with different segment lengths, volumes, weights, and modes is embodied in the final vehicle product. 0965-8564/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.tra.2011.11.010 ⇑ Corresponding author. Address: 5000 Forbes Ave., 115 Porter Hall, Pittsburgh, PA 15213, United States. Tel.: +1 412 268 2940; fax: +1 412 268 7813. E-mail address: rnealer@gmail.com (R. Nealer). Transportation Research Part A 46 (2012) 588–601 Contents lists available at SciVerse ScienceDirect Transportation Research Part A journal homepage: www.elsevier.com/locate/tra