Fig. 8
From: Multi-modal and multi-layer robustness analysis of the European rail and air networks
Distribution of node topological indicators for the European rail and air networks. Node degree (left) represents, for each node, the number of directly connected nodes. In the case of rail, almost 55% of the nodes have a degree around 3. For air, in contrast, nodes with higher degrees are likely, ranging from 12 for Kosice (SK) to 121 for London (UK). Node betweenness, representing the share of shortest paths from any origin to any destination that traverses a specific node, is shown on the right. The highest betweenness value is 0.34 for Wien (AT), indicating that 34% of routes in the network pass through that node. The air network has a smaller range and lower values. Almost 90% of air nodes have a coefficient nearly equal to 0. suggesting a high level of redundancy.
