This paper considers the engineer's, economist's, manager's, and planner's perspectives on transportation efficiency, respectively. The measures used in each perspective are examined, and the relative advantages and disadvantages of each are studied for various purposes. Each measure is illustrated with an example drawn from the case of the Twin Cities ramp metering shut off. The first section summarizes various measures of mobility that are used to assess transportation. This is followed by an exposition of transportation consumer surplus and its limitations. Similar treatment of accessibility and productivity are provided. The conclusions call for consideration of equity in addition to efficiency when evaluating broader effectiveness and for taking the subjective point of view of the traveler rather than the "objective" point of view of the omniscient planner/engineer/economist/manager.
Abstract