ABSTRACT
Off the western coast of Izu O Shima Island is located outside Tokyo Bay and have high congestion. In order to prevent traffic incidents in the area by separating the traffic flow according to navigational direction, Japan Coast Guard (JCG) implemented a new recommended route using virtual AIS. The route was designed by referring results of safety assessment based on projected traffic and was commenced on 1st January 2018. The authors have carried out follow-up research on the change of the traffic flow using AIS ship position data. It includes (i) analysis of ship traffic behaviour by focusing on the rate of ships that observe the recommended route, and (ii) safety assessment by encounter frequency and OZT (Obstacle Zone by Target), which were applied in the original design process of the recommended route. The results indicate that the rates that ships following the recommended route are growing after the start of the service; however, they differ depending on the path. The overall encounter frequency and the number of OZT after the implementation have been mitigated, compared to those of the traffic before the implementation.
