Office of Naval Research - National Transportation Library

Figure 27 – Modal Comparison of Ton Miles of Freight Carried per Gallon of FuelTon MilesTon Miles of Freight Carried perGallon of Diesel Fuel6005004003002001000Source: USDOT EstimatesTruck Rail Tug-BargeShare of fuel in a truck’s total operating cost is much higher than rail or barge. An estimated46 percent of a truck’s operating cost is fuel, compared to 35 percent for rail and 18 percentfor a container-on-barge operation. 72 Note that any estimate of fuel usage is highly sensitiveto assumptions about the tonnage carried in a typical load and the particular model used toestimate fuel use. For instance, the 2007 TTI study cited above used the EPA data from theMOBILE6 model to estimate trucking emission data. For rail emissions, TTI used theSurface Transportation Board (STB) and the Security and Exchange Commission (SEC) data,and for marine fuel efficiency the study used data obtained from the Tennessee ValleyAuthority fuel consumption model. Based on these input data, TTI estimated that an averageinland tug-barge carries 576 ton-miles per gallon of fuel, compared to 413 ton-miles carriedper gallon of fuel used by a railcar, and 155 ton miles per gallon of fuel used by a truck.These estimates showed far higher rates for ton-miles of freight for rail and truck than theDOT data, but comparable figures for tug-barge vessels. 735-6 Estimating the Benefits from Improved Driver and CrewProductivityWith respect to labor productivity, several metrics indicate significant advantages of a singlebarge over a truck carrying freight. A small crew (e.g., an average size barge crew of 10)operating a 15-barge tow can move 22,500 tons of freight; the same load when moved bytruck trailers (assuming an average truckload of 26 tons) would require the labor of 865single truck-trailer drivers.SSS offers the potential to alleviate some of the current labor shortages problems in thetrucking industry as well as the capacity shortages for railroads. Because SSS operations72 Transportation Economics & Management Systems, Inc., (TEMS), Impact of High Oil Prices on FreightTransportation: Modal Shift Potential in Five Corridors, Technical Report, Prepared for MARAD, USDOT,October 2008.73 C. James Kruse et al, A Modal Comparison of Domestic Freight Transportation Effects on the GeneralPublic, Texas Transportation Institute, December 2007; http://tti.tamu.edu/documents/TTI-2007-5.pdfONR SSS Final Report 64