## 3 Conformity Review According to Fairway Design Standard
### Analysis of Marine Traffic Congestion for Fairways  
In the Maritime Safety Act, the impact of maritime development projects on maritime traffic safety is investigated and evaluated in advance by the MTSA to eliminate risk factors. In addition, a maritime traffic congestion evaluation must be performed when designating or changing a fairway. Most safety diagnoses currently being conducted evaluate the degree of congestion using the bumper model [33]. The maritime traffic congestion assessment involves evaluating the current capacity by comparing the maximum traffic capacity that the fairway can accommodate with the traffic capacity actually being used. In MTSA, the number and size of ships passing the target fairway are investigated now and, in the future, and the results are presented after comparing the actual traffic volume with the maximum practical traffic volume that can be accommodated in the fairway based on this. Equation (3) shows the method to calculate the maritime traffic congestion [34,35]. \[T_{C}(\%)=\frac{Q_{T}}{Q_{P}}\times 100(\%) \tag{3}\]  
where  
\(T_{C}\)Traffic Congestion;  
\(Q_{T}\)Traffic Volume;  
\(Q_{P}\)Practical Traffic Volume;  
Figure 5: (a) L-converted traffic volume by time in the Wando fairway, (b) Yeosu area in Specific Traffic Safety Waters, (c) the Masan fairway, and (d) the Gadeok fairway. Traffic capacity is divided into basic traffic capacity and practical traffic capacity. The basic traffic capacity means the maximum number of ships of a certain size per hour that can be accommodated when passing a waterway with a certain width at a constant speed. The basic traffic capacity refers to the maximum number of ships that reflects the area occupied by ships passing through the fairway as it is; thus, it indicates the maximum number of ships that can travel without a safety margin. However, because vessel navigation can be affected by factors such as sea and weather conditions, vessel navigation freedom, and maritime traffic management method, the actual applicable capacity is referred to as the practical transport capacity, and 20-25% of the basic transport capacity is applied [36]. The ship operator strives to maintain a certain safe distance from other ships, obstacles, and low-depth areas, to ensure the safety of their ship. This safe area around one's ship is called the occupied area of the vessel, and to evaluate the degree of traffic congestion, the occupied area of each vessel should be considered. When evaluating the vessel congestion in Maritime Traffic Safety Assessment, the occupied area of a ship is usually 8 L in the front and rear and 3.2 L on the side of the standard ship length in wide waters, and 6 L in the front and rear and 1.6 L on the sides in narrow waters [34]. In this study, an 82 m long vessel applied to the L-converted traffic volume was set as the standard vessel. The basic traffic capacity can be obtained by dividing the product of the fairway width by the average ship speed on the fairway and size of the occupied area of the ship, as expressed in Equation (4) [35]:  
\[Q=\frac{1}{\gamma\textsuperscript{s}}WV \tag{4}\]  
where \begin{tabular}{l l l} \(Q\) & Basic Traffic Volume; \\ \(\gamma\) & Long Diameter of occupied area of standard vessel (km); \\ \(S\) & Short Diameter of occupied area of standard vessel (km); \\ \(W\) & Fairway Width (km); \\ \(V\) & Vessel Speed (km/h) \\ \end{tabular}   
Although each target fairway is near a port, because it is a relatively free navigation area, the ship's occupied area reflects the standard ship length of 8 L in front and rear and 3.2 L on the side. The traffic volume was thus analyzed. Table 5 shows the basic traffic capacity and the practical capacity for each target fairway. Since the speed of a ship differs based on the ship size, it is difficult to apply a specific speed. To compare whether the degree of congestion varies for each ship speed, we analyzed the congestion levels for 10 kts, 12 kts, and 15 kts.