Prioritizing investment projects for the rehabilitation of nautical bottlenecks: a cost-benefit-analysis to identify economic benefits

Abstract

The economic viability of the rehabilitation of nautical bottlenecks on inland waterways depends on the scope and sequence of carrying out the rehabilitation projects. The authors develop a modular cost-benefit analysis (CBA) tool, which enables an economic evaluation and prioritization of rehabilitation projects and show its functionality on a defined transport corridor. The tool calculates the Net-Present-Values (NPV) and Benefit-Cost-Ratios (BCR) for each nautical bottleneck and marginal NPVs for neighbouring bottleneck combinations. Finally, a Greedy-Algorithm is used to rank the investment projects. The findings show a strong path dependency, which means that benefits arise solely when all bottlenecks were rehabilitated. Isolated measures are mostly ineffective. Using the algorithmic approach facilitates a planning of investment projects within the transport corridor. The study contributes theoretically by enlarging the current state of literature in the field of economic evaluation of transport infrastructure investments. Practically, the paper contributes by providing an adjustable CBA tool which facilitates decision-making for policy, project sponsors or waterway maintenance companies. Further research should focus on using real transport and vessel data and the integration of ecological aspects, which could be additional factors, for or against carrying out rehabilitation projects.