ABSTRACT
Several collision risk indicators have been proposed for collision risk assessment and decision-making models for preventing ship accidents. The present study aims at characterising the collision risk indicators in ship-ship encounter scenarios by analysing the ship collision avoidance behaviour. First, evasive manoeuvres from ship trajectories involved in near collision scenarios are detected and classified according to encounter type and action obligation. Then, collision risk indicators, including the Distance to Closest Point of Approach (DCPA), Time to Closest Point of Approach (TCPA), relative speed, relative distance, relative bearing are calculated at the time the evasive action is taken. A statistical analysis is then conducted to characterise probabilistically the collision risk indicators in the ship evasive manoeuvres. The results of this study can be used as the basis for ship collision avoidance decision-making.
