Abstract
This paper develops a quantitative model for evaluating the difficulty of ship-handling caused by a restricted manoeuvring area or by traffic congestion or by a combination of both. It includes acceptance criteria based on the mariner's perception of safety. An attempt is made to evaluate the model by applying it to the specific environmental conditions of major ports in Japan. The model can provide information on the degree of ship-handling difficulty and so enable better design of infrastructure for waterways.