A discussion of the use of energy in the transportation sector. Transportation in the United States presently uses about 25 percent of the total annual energy budget, and the use of energy in the sector is increasing at an average annual rate of about 4 percent per year. Over 95 percent of this energy is supplied by petroleum fuels, and the biggest users are motor vehicles. Differences in modal efficiencies are shown, with motor vehicles and aircraft the least efficient energy users. The growth in energy use by transportation is shown to be due to increasing modal energy intensiveness, shifts in traffic from low intensiveness modes to high intensiveness modes, and increasing per capita use of transportation. (Presented at the Florida Governor's Conference on Energy Supply and Use, Tallahassee, Florida, March 13-14, 1973.) 12 pp. Ref.