## 2 Status Analysis of the Fairway
### Analysis of Appropriate Fairway Width Based on Design Standards  
To respond to the large-scale marine accidents that occurred continuously in Northern Europe in the 1960s, a study on the traffic separation method of ships was initiated in Europe (Ministry of Oceans and Fisheries, 2005). Afterwards, in 1968, the International Maritime Organization (IMO) developed a recommendation on the traffic separation method for 41 water zones, and after this recommendation, the number of participating waters significantly increased [22].  
The effectiveness of the traffic separation method has been presented in various studies. A study on the Strait of Dover in the UK showed that after the installation of the traffic separator, marine accidents decreased by approximately 23% compared to before installation [23,24]. According to [PERSON] et al. (2003), a risk analysis using the comprehensive environmental stress model indicated that the ship operator's burden on operating was reduced by approximately 32% compared to the previous status after the installation of the traffic separation zone, and it was observed that marine accidents were reduced [25].  
Although the IMO states that the fairway width of the traffic separation method should consider the traffic density, traffic mode, and available ship operating waters, it does not provide specific numerical values.  
In maritime traffic safety diagnosis, the Port and Fishing Port Design Standards and the Harbor Approach Channels Design Guidelines of the International Association of Water Transportation Facilities (PIANC Rule) are reviewed to determine the appropriateness of the design of fairways. In these design standards, when designing the width of a channel approaching a port, based on the size of the largest vessel passing through the target sea, one-way and two-way traffic are separated and presented as standards [26, 27, 28].  
In the PIANC Guideline, the width of the fairway is determined according to the characteristics of the ship, sea environment, navigation speed, shape of the seabed, and type of cargo [29].  
Equation (1) shows the required path width of a one-way channel according to the PIANC Guideline:  
\[\text{W}=W_{BM}+\sum W_{i}+W_{BR}+W_{BG}=W_{M}+W_{BR}+W_{BG} \tag{1}\]  
Equation (2) shows the required width of a two-way channel according to the PIANC Guideline:  
\[\text{W}=2W_{BM}+2\sum W_{i}+W_{BR}+W_{BG}+\sum W_{P}=2W_{M}+W_{BR}+\sum W_{P} +W_{BG} \tag{2}\]  
where  
\begin{tabular}{l l} \(W_{BM}\) & Basic maneuvering lane; \\ \(\sum W_{i}\) & Additional widths to allow for the effects of wind, etc.; \\ \(W_{BR}\), \(W_{BG}\) & Bank clearance; \\ \(\sum W_{P}\) & Passing distance between both maneuvering lanes \(W_{M}\). \\ \end{tabular}  
Table 2 shows the effects of ship speed, sea environment, navigation method, and the range of basic and additional fairway width conditions suggested in the PIANC Guide.  
Based on Equations (1) and (2), when the conditions mentioned in Table 2 are applied, the appropriate bidirectional fairway width according to the PIANC Guide is analyzed to be a minimum of 3.8 B and a maximum of 18.6 B.  
Similarly, in Korea's Port and Fishing Port Design Standards, the fairway width should be determined by fully considering conditions such as the specifications and characteristics of the target vessel, marine environment, and traffic situations. However, considering the traffic situation, clear standards are presented to a certain extent. Where two-way traffic is not expected, a fairway width of 0.5 L or more is preferred, and where two-way traffic is expected, the default fairway width is 1.0 L or more. In the case of a long fairway, a fairway width of 2 L or more must be secured. Table 3 shows the fairway width standards according to the port and fishing port design standards [30].