Analyzes past energy growth rates in the transportation sector and makes some projections for the near future. The average annual rate of growth of energy use in the transportation sector from 1955 to 1968 was about 3.9 percent. When this is broken into the transportation of freight and the transportation of people, it is found that the former had an average annual growth rate of about 2.5 percent, and the latter had an average rate of about 5 percent per year. Further disaggregation identifies the components of the growth rate in energy use as increasing population, changing modal energy intensiveness, modal shifts, changing per capita personal travel, and changing per capita freight. Of these, the single most important factor appears to be changes in per capita personal travel, which may be growing at the average rate of about 3.5 percent per year. Much of this increase in personal travel may be via air carriers, which use more energy per unit of travel than other transport modes. 9 pp.