Cascading dominates large-scale disruptions in transport over complex networks
Fig 4
Total (summed) delay jumps, sorted by various mechanisms that cause them, and subdivided in ‘labels’, for Panel (a) one case study (11 December 2017), and panel (b) their proportions averaged over four days each for four day classes (‘Black’, ‘Red’, ‘Neutral’ and ‘Green’) for the Dutch railways. The origins of the delay jumps were identified by comparing observed data to model output. Magnitudes [panel (a)] and relative magnitudes [panel (b)] were calculated for time windows of 5 minutes, with a 30-minutes smoothening window used for display purposes. Four types of delay jumps that act as delay sources are distinguished: (I) delay cascading due to crew transfers (purple), (II) delay cascading due to rolling stock transfers (red), (V) other larger incidents (blue) and the positive part of (VI) net noise. Three types of delay jumps that act as delay recovery are distinguished: (III) mitigated cascading due to rescheduling (yellow), (IV) mitigated cascading due to cancellations (green), and the negative part of (VI) net noise. The positive part and the negative part are plotted separately in a cumulative sense—up- and downward, respectively. In panel (b), the total identified delay cascading (observed plus mitigated) is highlighted in hours.