The Scientific Foundation for Impacts Estimation in Transportation Appraisal: A Literature Review

Public guide lines for transportation appraisal consider a wide range of impacts of spatial measures with focus on transportation investments. Although the appraisal frame works in the guide lines are based on a sub stantial scientific lit er a ture, few studies map the literature systematically. In this review, we provide a systematic over view of the scientific foundation for the pres ence and quantification of a large variety of impacts in transportation appraisal. We focus on immature parts of the literature that address impacts considered to be of potentially large magnitude, but that are commonly excluded from cost-benefit analyses interalia due to uncertainty.