Bottlenecks in Transportation Research: Understanding Behavior,the Alpha and Omega for the Applicability of Applied Research

There are some basic problems of transportation research that, for many reasons, should be termed bottleneck problems. The terms “behavioral relevance” and “prediction of behavior” indicate that a description of behavior must reflect actual behavior. This is necessary for a description that can contribute to predicting behavioral patterns. These predictions, in turn, are essential to most transportation studies that involve human behavior. The following bottleneck problems are discussed in detail: behavior-relevant private car costs; behavior-relevant time costs; generalized costs and cost-benefit analysis; attitude surveys and self-knowledgeability; forecasting history versus forecasting the future; and indirect effects and the perfect traffic forecast. All these problems are much too important to be solved by sweeping them under the carpet—which in many ways is what we are doing now.