Abstract
The current interest in energy conservation has resulted in a spate of divergent estimates of the energy intensiveness (EI) of urban transit modes. This paper critically reviews the methodologies and data sources employed by these estimates. It is shown that a very small repertory of sources and methodologies underlie the EI estimates, and that variance among them is primarily attributable to contradictory load factor assumptions. El estimates for bus and rail transit are developed, and the inadequacies of automobile data are discussed. Buses are shown to be more efficient than rail transit, and it is shown that light rail’s energy advantage over heavy rail lies in construction, not operation.