Analyzes the use of energy for transporting U.S. intercity freight and the effect of higher fuel price. Several original methods of estimating unit energy consumption are developed and applied to determine average values and trends. Water transport is found to consume an average 500 Btu per ton/mile; rail, 750; pipeline, 1,850; truck, 2,400; and air cargo, 63,000, or 45 times the average for all transport modes in 1968. Only a small shift to air freight, from the present less than 0.2 percent to 2 percent of all intercity ton/miles, would double the average unit energy consumption for all freight modes. If present trends continue, this increase will occur by the year 1996. Because of its high fuel consumption, however, air freight growth would tend to be inhibited by higher fuel prices, while surface transport would be little affected. Higher fuel prices may result from shortages, the cost of environmental constraints, new taxes, or other reasons.