# Modeling of Vessel Traffic Flow for Waterway Design-Port of Swinoujscie Case Study
## 1 Introduction  
In the context of high and increasing interest in maritime space for different purposes, the establishment of new areas of maritime infrastructure or ecologically specific areas will be necessary. Such interventions will also lead to changes in the nature and parameters of shipping routes. A tool is therefore needed to analyse the impact of changes in maritime space. The study of shipping traffic flows is crucial to the safety and efficiency of navigation. Analysis of vessel traffic helps to understand ships' navigation patterns and provides the necessary input for maritime risk assessment tools. Specific models need to be created for selected areas. A general model of vessel traffic flows for the Baltic Sea is the goal of the studies. The studies on risk analysis have enhanced the work on traffic flows. The first studies were based on a random spatial distribution of ships with no distinction between ship types [1,2]. A normal and uniform distribution over coastal areas, vessels, and navigational infrastructure characteristics was used as the theoretical distribution [3]. Vessel distribution adjustment studies were conducted for coastal areas, necessitated by limited access to data [4]. The authors proposed to calculate the probability of collision or grounding by defining the lateral limits of the navigable area in a Weibull-, Rayleigh-, or Gaussian-type distribution. Expert studies on a group of navigators, based on radar data analysis, were used to conduct offshore collision risk studies. It has been shown that the distribution of ship distance from the average route depends mainly on the length of the route [5]. A linear model of ship positions on track was constructed. Consideration of more independent data for the model was used by [PERSON] [6]. Vessel traffic was classified according to vessel type, displacement, length, whether it was loaded or ballasted, ship speed, draught, and ice-class. The author created a modelto calculate the collision risk in busy shipping lanes and studied the distribution of the different traffic classes. Currently, AIS data are used in studies of actual ship behaviour. In recent years, numerous studies have been conducted to assess collision risk and traffic. A model presented by [PERSON] and [PERSON] [7] is based on an extensive dynamic microsimulation of vessel traffic using the Monte Carlo simulation. Inputs to this model include routes, number of vessels on each route, departure times, ship dimensions, and speed. Detailed studies of vessel traffic statistics were conducted. Since the traffic looks different in different maritime areas, the studies are conducted to determine the parameters of traffic flows for specific waters. Studies on shipping traffic flow have been conducted in the Baltic Sea [8; 9], in the Japan Strait [10], in the Adriatic Sea [11], in the port of Lisbon [12], off the coast of India [13], in the Singapore Strait [14]. and in China: the Dagusha Channel [15] and the Ningbo-Zhoushan Port [16]. Two comprehensive studies on traffic analysis in the Istanbul Strait have been published [17; 18]. The statistical analysis of vessel traffic and the collision risk model off the coast of Portugal have been developed [19]. A classical traffic flow theory was used in an initially developed mathematical model [20]. A back propagation (BP) neural network was used to predict vessel traffic flow [21]. Forecasting models of vessel traffic flow using a radial basis function (RBF) neural network, grey forecasting, auto-regression, and a combined model with support vector machines (SVM) were presented by [PERSON] [22]. A novel method for modelling maritime traffic based on the concept of potential field was created by [23], where the fluctuations of traffic relative to time are studied. Automatic detection of traffic flow based on kernel density estimation is proposed by [24]. The paper presents studies of traffic flow in the approach to the port Swinoujscie as a part of research into a general mathematical model of vessel traffic streams. AIS data are used.