Assessment of large transport infrastructure projects: The CBA-DK model

The scope of this paper is to present a newly developed decision support model to assess transport infrastructure projects: CBA-DK. The model makes use of conventional cost-benefit analysis resulting in aggregated single point estimates and quantitative risk analysis using Monte Carlo simulation resulting in interval results. The embedded uncertainties within traditional CBA such as ex-ante based investment costs and travel time savings are of particular concern. The methodological approach has been to apply suitable probability distribution functions on the uncertain parameters, thus resulting in feasibility risk assessment moving from point to interval results. Decision support as illustrated in this paper aims to provide assistance in the development and ultimately the choice of action while accounting for the uncertainties surrounding transport appraisal schemes. The modeling framework is illustrated by the use of a case study appraising airport and runway alternatives in the capital of Greenland - Nuuk. This study has been conducted in corporation with the Home Rule Authorities of Greenland.