Methods for Estimating the Volume and Energy Demand of Freight Transport.
Explores methods for discovering what determines freight volume (particularly that of rail, the carrier mode with the largest share of freight traffic) to permit prediction of freight demand and, ultimately, the demand for energy in the future. The methods are (1) graphical analysis, (2) ordinary least-squares regression analysis, (3) stepwise regression analysis, and (4) factor analysis; they are applied to a database of 1939-1968. GNP proved a good predictor of freight volume for all modes except rail. For the latter, coal production and durables manufacture are much better indicators. The volumes of motor vehicle, air, and, to a lesser degree, pipeline transport are particularly sensitive to prices. No single method proved entirely satisfactory; use of all four is probably necessary for making reliable predictions. (See also R-804.) 77 pp. Bibliog.