# Improving the Maritime Traffic Evaluation with the Course and Speed Model
## 5 Conclusions and Future Work  
Recent statistical data from marine transportation market research organizations indicate that maritime traffic volume might increase owing to global economic recovery and the impact of the fourth industrial revolution. Consequently, the prediction of marine accidents and the management of maritime traffic using risk assessment methods hold significant importance. However, unlike road traffic with real-time monitoring, maritime traffic requires optimizations based on historical data. The use of historically used navigation patterns or conventional routes occurs because they have been tested and verified for a long time, and the accumulated data of actual ship passage prove it and are reliable. Therefore, evaluating the suitability of maritime traffic flow necessitates a macroscopic perspective. To achieve this, this study classified maritime traffic characteristics into spatiality, continuity, specificity, and safety. Among these, spatiality and continuity, reflecting the output of ships, were considered to macroscopically assess the smoothness of maritime traffic flow based on ship AIS data. The employed CS model assessed maritime traffic flow using the changes in course and speed. This involved analyzing the COG, ROT, speed, and acceleration of each ship at specific points and calculating the deviation from the standard plan. The analysis results of maritime traffic flow for the first sea route of Ulsan Port using the CS model are as follows: the outbound continuity index is higher than the inbound, and the inbound spatiality index is higher than the outbound. However, the same trend was not observed for different ship sizes. The outbound and inbound CS indices were measured at 0.7613 and 0.7501, respectively. This means that, in the target sea area, the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Continuity Index**} & \multicolumn{2}{c}{**Spatiality Index**} & \multicolumn{2}{c}{**CS Index**} \\  & **Outbound** & **Inbound** & **Outbound** & **Inbound** & **Outbound** & **Inbound** \\ \hline S1 & 0.8201 & 0.6897 & 0.7732 & 0.7930 & 0.7967 & 0.7414 \\ S2 & 0.7879 & 0.7756 & 0.6516 & 0.6852 & 0.7198 & 0.7304 \\ S3 & 0.8126 & 0.7751 & 0.6718 & 0.6868 & 0.7422 & 0.7310 \\ S4 & 0.8172 & 0.7782 & 0.7476 & 0.6771 & 0.7824 & 0.7277 \\ S5 & 0.7497 & 0.8012 & 0.7817 & 0.8386 & 0.7657 & 0.8199 \\ Avg. & 0.7975 & 0.7640 & 0.7252 & 0.7361 & 0.7613 & 0.7501 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of the CS index. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Dk(0)**} & \multicolumn{2}{c}{**Dk(r)**} & \multicolumn{2}{c}{**Spatiality Index**} \\  & **Outbound** & **Inbound** & **Outbound** & **Inbound** & **Outbound** & **Inbound** \\ \hline S1 & 0.8359 & 0.8583 & 0.7105 & 0.7277 & 0.7732 & 0.7930 \\ S2 & 0.6148 & 0.6873 & 0.6884 & 0.6832 & 0.6516 & 0.6852 \\ S3 & 0.7054 & 0.7688 & 0.6383 & 0.6049 & 0.6718 & 0.6868 \\ S4 & 0.7772 & 0.6367 & 0.7181 & 0.7175 & 0.7476 & 0.6771 \\ S5 & 0.8115 & 0.8850 & 0.7519 & 0.7922 & 0.7817 & 0.8386 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Results of the spatiality index. outbound ship flow demonstrates a slightly weaker adherence to the standard plan than the inbound flow, impacting the fluidity of maritime traffic. Several factors influenced the CS index, including ship-related factors that determined the dynamic performance of the vessel, traffic conditions that assessed the surrounding traffic environment, open sea and harbor approaches, traffic volume, pilot services, and time. The assessment results of this research show that the characteristics of the sea route approaching the port are reflected in the CS model. This model quantitatively analyzes spatiality and continuity, two crucial characteristics of maritime traffic, to assess the smoothness of maritime traffic flow. Moreover, the model allows for intercomparisons based on the assessment range and time, offering valuable insights.