Modelling of ship overtaking risk in restricted waters considering ship-ship interaction

Overtaking in restricted waterways is a common navigation scenario with a high risk of collision due to ship-ship interaction and unexpected events. This paper proposes an analytical method for assessing overtaking risk in busy waterways by considering both longitudinal and transverse safe distances. The approach involves establishing a three-layer overtaking risk framework that identifies the influencing factors through scenario analysis of ship overtaking, ship-ship interaction, and ship-following. The safe criteria for fuzzification in both longitudinal and transverse directions are defined, and the overtaking risk is integrated using fuzzy logic. The proposed approach is applied to 100 historical data in the Yangtze River, and the results of high and very high overtaking scenarios show that the model provides a practical and reasonable assessment of ship overtaking risk. The proposed model can be used as decision support for ship navigation in busy waterways.