## 1 Introduction  
The shipping industry is the most efficient mode of long-distance transportation [1]. The sea is used by more than 80% of the world's merchant ships, and various maritime traffic routes are used [2]. As a result, as the shipping industry develops and the demands of marine transportation increase over time, the size of ships has increased [3]. This phenomenon is strengthening the route design standards for the safe operation of ships and the prevention of marine accidents in each country and institution [4]. Moreover, due to the limitation of not being able to designate a route in all sea areas, ships are freely navigating in the sea area where there is no route due to economic considerations. In other words, most ships take similar routes because they are developed to travel the shortest distance possible, which is an economic consideration, and to seek safe and efficient routes with the least amount of risk [5]. Recently, in the area of ship routes, friction is increasing with ecofriendly energy projects, marine ecosystems, and fishing activities. This demonstrates the complexities of marine activities, which can result in marine accidents and environmental pollution, the consequences of which can be catastrophic [6]. In this study, a national main maritime route is developed and presented as a one-of-a-kind route for ship navigation. Worldwide, ecofriendly energy development is being actively carried out to protect the environment and reduce carbon dioxide emissions [7]. Wind power is one of the fastest-growing ecofriendly energy sources [8]. Wind power generation is being installed on land and offshore, and it is shifting to the sea due to social issues and land development constraints [9]. This movement has an impact on ship safety because it leads to large-scale installation at sea [10]. In addition, the development of Marine Spatial Planning (MSP)divides spatial and temporal zones using the ocean and preserves sensitive areas [11]. In the case of Korea, there are nine maritime spatial plans. Merchant ships use three types of ports and navigation areas in this maritime space: traffic designated areas, harbor areas, and Traffic Separate Schemes (TSS). Ships' traffic routes outside of legally mandated ports and shipping zones are not preserved [12]. Therefore, it is intended to understand the traffic flow in the coastal waters of Korea and to preserve the main maritime traffic flow. It is expected that this will secure the maritime traffic area in the maritime space and result in safe vessel operation at sea. Furthermore, it is only intended to be used to create a national maritime traffic route map, and it is presented as a methodology. It utilizes the ship's automatic identification system (AIS) data to create a maritime traffic route. AIS data include Maritime Mobile Service Identity (MMSI), Global Positioning System positions, speed over ground (SOG), course over ground (COG), type of ship, length of all (LOA), breath of ship, and time and place of arrival, and adjacent ships and AIS stations exchange data [13]. The International Maritime Organization (IMO) mandates that cargo ships with a gross tonnage of 300 tons or more engage in international voyages, ships with a gross tonnage of 500 tons or more do not engage in international voyages, and all passenger ships have AIS [14]. AIS data are an important component for analyzing a ship's operational pattern. If the SOG, COG, Rate of Turn, Voyage Data Recorder, etc. of a ship are analyzed by density-based spatial clustering of applications with noise (DBSCAN) clustering, it is possible to identify the actual ship's engine order and use of rudder from the past data and prevent ship accidents. The work in [15] is an example. Recently, a large amount of real-time AIS data have been accumulated, and research using these data is being actively conducted [16]. AIS data are used in a variety of fields, but the parts relevant to this study can be divided into three categories. To begin, [PERSON] et al. and [PERSON] et al.