Influence of Changes in CO2 and Investment Costs on the Benefit-Cost-Ratio of Transport Infrastructure Projects

The German Bundesverkehrswegeplan (BVWP) is the national transport infrastructure assessment. It is done approximately every 15 years. One central part of it is a benefit-cost analysis (BCA) for each project. The last Bundesverkehrswegeplan (BVWP) is from 2016, and its methodology and cost factors bases on the year 2012. Since this time, there is a significant change in the cost factors for e.g., carbon dioxide (CO 2 )-prices, driven by the goal of climate neutrality by 2045/2050 in the European Union (EU). In this study, we recalculate the benefit-cost analysis (BCA) of the national transport infrastructure assessment using a more current CO 2 -price, as well as updated investments costs for the projects, and analyze the effects on the project’s assessment. Additionally, we include further cases to illustrate even more advanced (higher) pricing / cost schemes. We found that the selected price of the CO 2 emissions as well as the development of the investment costs have a significant influence on the project’s assessment. When changing only one of the two investigated effects (CO 2 -price OR investment costs) will cause 11% to 28% of the projects to fall under the threshold of benefit-cost ratio (BCR) equals 1. Not realizing these projects would save 6% to 34% of the overall investment costs and 8% to 33% of the additional annual CO 2 emissions. When considering both effects, the changes will be even more significant, with 25% – 46% of the projects falling to BCR < 1. Discarding them safes between 20% and 51% of the investment costs and reduces the annual CO 2 impact of the plan by 20% to 53%.