ENVIRONMENTAL IMPACTS OF A MODAL SHIFT

The need for a no-build alternative in the environmental analysis of water transportation projects and the environmental compatibility of water transportation are demonstrated. To make the demonstration, cargo from four regularly scheduled vessel movements was theoretically transferred to the highway and rail modes. Included in the cargoes studied were coal, aggregate, petroleum products, and wood paper products. All four movements had highway carriage as a feasible alternative, and two had rail service available. For the four movements, in total, the transfer of cargo from vessels to trucks would result in annual increases of 3,774,328 gal of fuel (an 825% increase), 573.9 tons of exhaust emissions (a 709% increase), 17.9 probable accidents (a 5,812% increase), and the need to dispose of 2,746 used truck tires. In addition, such a modal transfer would result in an additional 1,333 large semitrailer trucks in the travel corridors each day. For the two movements that had possible rail service, the annual impacts of a modal shift from water to rail are an increase in fuel use of 899,741 gal (a rise of 259%), an increase in exhaust emission of 265.7 tons (up 408%), and an increase in probable accidents of 0.35 (a 150% increase). In addition a modal shift of the cargo from vessels to trains would mean the involvement of an additional 75 trains of 100 cars each at 193 highway crossings and 38 at 177 road crossings.