Figure 1. Heterogeneous topology, traffic, and length of stay of the mobility network by air travel in Europe.

Statistical fluctuations are observed over a broad range of length and time scales. (a) The degree distribution P(k) of the European airport network is characterized by large fluctuations indicating a heterogeneous topology of the system. (b) The distribution of weights in the European airport network is skewed and heavy-tailed. (c) The number of nights spent by foreign travellers visiting the UK (in blue) and by British travelling abroad (in red) spans several orders of magnitude, from 1 night to several months, considering all travel purposes and all countries of origin and destination. (d) The number of nights spent by tourists travelling to European countries on holiday is similarly broadly distributed. Here we show data for 5 selected countries of destination, considering only trips of 4 nights or more (source: Eurostat).