Weighting the factors affecting safety of navigation: A case study for the Gulf of İzmit, Türkiye

Cargo transportation is globally carried by sea. The increasing population and associated needs increase the amount and diversity of cargo transported by vessels. The tonnage and number of vessels are also increasing accordingly. Although production and storage points are established in the regions where raw materials are located, they are concentrated in coastal areas in accordance with intermodal transportation. The Gulf of Izmit is the maritime region with the largest maritime facilities in Türkiye due to its location within the Turkish Straits, its dense population, its proximity to production and raw materials, and its strategic location where transportation modes intersect. Vessel Traffic, Pilotage, and Tugboat Services units operate in the region in order to increase the safety of navigation. However, many factors, such as geographical, meteorological, and hydrographic conditions of the region, and critical structures, local traffic, fishing activities, and the presence of dangerous cargo terminals, affect the safety of navigation. In this study, it was decided to use the Analytic Hierarchy Process (AHP) method, one of the Multi-Criteria Decision Making (MCDM) techniques, to identify the factors affecting navigational safety in Gulf of Izmit, to rank them in order of importance and to determine the measures to be taken. In this context, firstly, an extensive literature review was conducted. The data obtained were analyzed by 10 people who are experts in their fields, have academic backgrounds, and work in the region as pilots, vessel traffic operators, port state control officers, and oceangoing masters. Dynamic (variable) and static (unchangeable) risks in the region were identified and a hierarchical structure was obtained. The weights of the factors within the hierarchical structure were determined by making numerical comparisons with each other and the importance ranking was revealed.