light-duty trucks, but this opportunity to conserve fuel depends on resolution of the air quality issues associated with diesel emissions.
The 7–14 percent savings in fuel that can be realized in trucks by conservative driving may not be achieved even at much higher fuel prices, since the costs of labor and capital substantially outweigh that of fuel in the truck freight business, where both wages and depreciation of equipment are time dependent and revenue is distance dependent. Any fuel-conserving measure that increases the time per trip incurs costs in wages and capital that fuel savings would be hard pressed to match.11
Removal of Interstate Commerce Commission restrictions on commodities, routes, and backhauls would allow the trucking industry to plan for fully loaded round trips, improving the industry’s load factor.12
Railroads, which account for about 1 percent of national energy consumption, are highly energy efficient for long-haul freight. A shift of long-distance freight transportation from truck to rail could be accomplished by major changes in regulatory policies, to allow, for example, the formation of integrated transportation companies free to seek optimum combinations of truck and rail freight through competition.
Table 2–3 sets out demand for energy by the transportation sector in 2010 under the Demand and Conservation Panel’s scenario assumptions. Improvements in energy intensity assumed under the conditions of each scenario are included for ready comparison.
In scenario C, the real price of energy remains constant, but even so the energy intensities of all forms of transportation drop, consistent with historical patterns under falling real prices for energy. Prevailing standards for improvement in automobile fuel economy are assumed to be met, and as automobile travel begins to reach saturation (in cars per owner, minutes spent in automobiles daily, etc.), air travel claims a larger percentage of expenditures for passenger transportation.
In scenario B, prices for energy have climbed steadily to twice the 1975 levels by 2010, and in response the fuel efficiency of automobiles has doubled. Rail freight has expanded by 30 percent, truck freight has grown by 40 percent, and air freight has tripled.
In scenario A energy prices quadruple by 2010, and public policies accelerate the response to this energy conservation incentive. As a result, present federally mandated standards for automobile fuel efficiency are met and superseded by new standards. By the year 2000, advanced fuel-conserving technology (perhaps Brayton and Stirling engines) would begin to be used in new automobiles. Air travel would increase by about 60 percent, and under this intensified demand as well as public policies