Fig. 4: Movement patterns of major shipping companies.

a Shipping routes for the major companies, where the blue lines denote the routes starting from Singapore while the red lines are those starting from Rotterdam. From left to right, these are COSCO (China Ocean Shipping Company), Maersk, NYK (Nippon Yusen Kaisha), and Hapag-Lloyd; b the extracted movement patterns of these companies from the actual trajectories. Blue lines represent trajectories departing from Singapore, while red lines represent trajectories departing from Rotterdam.