Time efficiency assessment of ship movements in maritime ports: A case study of two ports based on AIS data

Operational efficiency of a maritime port is an important issue for shipping lines and port authorities. It is desirable to move ships in and out of a maritime port as efficiently as possible. Automatic identification system (AIS) data recording the trajectory of ship movements allow us to assess the operational efficiency as ships move in and out of a port. This study proposes a time efficiency assessment framework that evaluates the amount of time each ship spends in the different areas within a port (i.e., berth, anchorage, and fairway) based on the space-time trajectories of ship movements derived from AIS data. According to the statistical distributions of time spent by different types of ship in each port area, the proposed framework can compare time efficiency across different zones within a port and between different ports. This study uses AIS data of four types of ships (i.e., container, cargo, tanker, and passenger ships) at two selected ports in China, Shanghai Yangshan Port and Xiamen Port, to demonstrate how the proposed approach can effectively assess and compare time efficiency levels of ship movements between the times entering and leaving the vessel traffic service (VTS) lines of a port. This study demonstrates the value of deriving space-time trajectories from AIS data based on the concepts of time geography to assess time efficiency levels of maritime ports and monitor their performance over time, which offer useful information to both shipping lines and port authorities for operations such as efficient scheduling and logistic support.