Simulation of the vessel traffic in the strait of Istanbul

Abstract

Turkish Straits are of vital importance for Turkey since they interconnect the Mediterranean Sea and Black Sea. In particular the Istanbul Strait which is one of the narrowest and busiest waterways in the world (more than 50,000 vessels per year), carry high risks for both vessels and people living in Istanbul. In order to minimize these undesired incidents, the Turkish authorities establish maritime traffic regulations for vessels while entering and passing the Strait. In this study, a simulation model is designed to mimic the actual Istanbul Strait vessel flow under the established traffic regulations and meteorological conditions. Arriving vessels which are classified according to their cargo and length usually have to wait a certain amount of time (in their respective queues according to type and length) before being admitted to the Strait (due to the main traffic regulations regarding vessel density and composite sailing in the Strait). The one way daytime traffic starting direction and number of vessels planned to enter from each direction are formulized and vessels with respect to their assigned priorities transit in this direction when the determined minimum pursuit distances between each other, meteorological conditions and tugboat or pilot needs are satisfied. The number and types of vessels scheduled in nighttime traffic (which allows two way transits) is also formulized. The number of pilots and tugboats scheduled in the traffic flow direction, visibility, current and storm information are also integrated to the model. In this respect, average waiting time of vessels and for each class, total number of vessels passed from each direction, transit times, number of vessels in the queues, vessel densities throughout the Strait and pilot utilizations are selected as performance measures and their results are compared with the actual values obtained from 2009 data for investigating the model accuracy. Furthermore, the individually and interactive effects of vessel arrival rate, number of available pilots in the system, vessel profiles and minimum pursuit distances on the performance measures are investigated is concluded that arrival rate is the most influencing factor among others. Finally, the effect of visibility when the arrival rate is also at high rates is also analyzed and is deduced that the fog density in the Strait is also significant for the system performance measures.