Traffic impacts of the unavailability of road tunnels

  • Tunnels are often essential to provide efficient and safe road connections. However, due to their geographic localization and the tremendous impact that their partial or complete unavailability has on traffic, they are very critical infrastructures. It is therefore necessary to increase their resilience towards planned and unplanned events.    

  • Within the framework of the BMBF-funded (German Federal Ministry of Transport and Digital Infrastructure) project "Resilient Road Tunnels (RITUN)", the increase in the resilience of road tunnels towards external events is being examined by the project partners: the Federal Highway Research Institute (BASt), ILF Consulting Engineers and the motorway authority for southern Bavaria.

    PTV AG supported the project partners in this work by studying the effects on traffic of the unavailability or limited availability of two tunnels in the German road network and quantifying the associated macroeconomic costs. This work built upon the findings of previous projects, within which appropriate procedures were developed. For the two tunnels analysed, the effects of unavailability or limited availability were quantified for different scenarios that differ in terms of traffic restrictions and duration of these restrictions. The effects on traffic were determined using PTV Validate traffic model and an Excel-based control and evaluation module, which has been conceived and created during the project.


  • Partially automated calculation

    The control and evaluation module developed within the project can be used in combination with the PTV Validate traffic model to calculate the effects of a partial or complete unavailability of the tunnels semi-automatically.

    Derivation of measures to increase resilience

    The results of the analyses can be used to better evaluate possible measures to increase the resilience of tunnels as well as traffic management options after an event has occurred.

    Economic consideration

    By monetarising relevant indicators, the macroeconomic costs of a partial or complete unavailability of tunnels can be quantified. Since the approach used applies the evaluation methodology of the Federal Transport Infrastructure Plan 2030 (BVWP), investment decisions based on this methodology can be compared with projects’ requirement plan.