European air/rail intermodality network potential: a classification of hub integration

Abstract

Following the European Green Deal, transport- related emissions must be reduced by 90% in 2050. While aviation contributes to a significant share of these emissions, the substitution of flights for rail travel is often considered to achieve a reduction in emissions of greenhouse gasses. Mostly, travelers consider this option when the full trip can be substituted directly. However, possibilities also lie in intermodal travel, where specific journey parts are substituted. To promote this way of travel, the two modes should have a strong level of service, and there should be a significant level of integration between the two modes.
In this thesis, a method is presented to assess the position of airports’ in a European intermodal network. This tool helps identify airports with the potential to facilitate intermodal travel in Europe. The service levels in both the air and the rail network, the physical integration between the modes, and the geographical location of airports are considered in different variables to assess the network. A Principle Component Analysis identifies the shared information between the different variables. The Principle Components are then clustered using an Agglomerative Hierarchical Clustering. With this clustering, airports are grouped based on their characteristics of intermodal factors, and different roles in an intermodal network can be identified. Comparing the descriptive statistics of each cluster helps assign qualitative labels to the cluster to classify the airports’ roles. After creating the benchmark with data from the current network situation, scenarios are constructed to assess the effects of implementing different policies regarding intermodality. Extending rail services and/or reducing short-haul flights are policies formed into scenarios in which the underlying data is modified. The change of clustering and classifications caused by the data modification helps identify potentially interesting airports in the network.
The results show that 20 to 30 of the 113 considered airports show a substantial role in intermodality. Also, the findings identify airports that change their position due to the scenario implementations and offer the potential for a significant role in an intermodal network. Finally, comparing the classifications in the different scenarios shows that the constructed scenarios can enable up to 14.3% extra passengers to travel intermodal.