Placing an economic dollar value on the environmental impacts of shifting products from the waterway mode to a land mode is presented. Since the original study, completed in 1991, two of the three modal shift examples discussed have taken place. What caused the modal shifts to take place and their merits are also examined. The fuel cost efficiency of the water mode is compared with that of land modes and the air emission results of burning additional fuel to move the same product tonnage. Freight rate variations between the modes are not discussed because the focus is on environmental impact cost. When comparable, waterborne transportation has an environmental cost impact of one-fifth that of rail and one-tenth that of truck transport. Accident rates on a per ton-mile basis are also discussed, but no dollar figures are available for comparison purposes at this time.