Traffic Separation Schemes Research Articles

Perform assessment of COLREGs onboard a maritime autonomous surface ship: Narrow Channels and Traffic Separation Schemes

Abstract The usage of Maritime Autonomous Surface Ships in coastal and heavily used maritime environments necessitates advanced navigation systems capable of fully complying with the International Regulations for Preventing Collisions at Sea 1972 and not only open sea encounters. A significant challenge in this domain is enabling autonomous vessels to understand and navigate complex collision avoidance scenarios dictated by Rule 9 Narrow Channels and Rule 10 Traffic Separation Schemes. These rules are not well covered by research and only partial solutions have been proposed. To address this, we propose a ruleset for a system that can blend the traffic situation and geometric constraints extracted from Electronic Navigational Charts in S-57 format. The proposed ruleset extends our previous work on operationalization of COLREGs by introducing spatial features describing the maritime geometries relevant for traffic situations in Narrow Channels and Traffic Separation Schemes. We apply the ruleset to various traffic situations, showing how the inclusion of geometric context improves decision-making by reducing ambiguity and therefore enables the assessment of traffic situations and ship encounters in the vicinity of Narrow Channels and Traffic Separation Schemes. Our work outlines how the integration of spatial features into a rule-based system enables autonomous navigation capabilities of MASS for safe operations and compliance with maritime regulations.

Verification of collision avoidance algorithms in open sea and full visibility using fuzzy logic

Autonomous Surface Vehicles (ASV) have been a subject undergoing intense study since they provide good potential regarding reducing the cost, increasing safety, reliability, efficiency and sustainability. The complexity of the ASVs needs to be tested to gain trust and to prevent fatal consequences. This paper proposes a method using fuzzy logic for evaluating the compliance of Collision-Avoidance Systems (CAS) with regard to the Convention on the International Regulations for Preventing Collisions at Sea (COLREG). For the proof-of-concept purpose, the set of rules for open sea and full visibility is considered; but the framework from this paper can be extended to include narrow channels, traffic separation schemes and restricted visibility by added more fuzzy rules. Fuzzy logic allows handling vague terms and represents linguistic variables and values written in COLREG in a quantitative mathematical form without introducing sharp assumptions or specifications to original COLREG. The paper develops four evaluation systems (1) evaluation of all vessels in pairwise encounters, (2) ownship (OS) evaluation in pairwise encounters for the interest of Class societies, (3) evaluation of all vessels in multiple-vessel encounters, and (4) OS evaluation in multiple-vessel encounters for the interest of Class societies. The designed systems were verified on a set of simulated scenarios. The obtained results were validated against visual assessment of the trajectory, heading and speed plots. The results showed that the evaluation systems provided variables that would be challenging or impossible to obtain by visual assessment.

Design and Safety Assessment of Recommended Route off the Western Coast of Izu O Shima Island

Ship routeing systems (e.g., traffic separation schemes) have been established worldwide to ensure ship traffic safety. There are no specific measures to establish an effective ship route. We have previously proposed a method to design and assess the route comparison with the present traffic flow in the interest to establish an effective ship routeing system, particularly for recommended routes. The method consists mainly of the following procedures: understanding the existing phenomena and the issues in the target area by analyzing target traffic flow; designing safety measures; assessing the safety measures; and determining the optimal safety measure. This method was used to design and assess the recommended route off the western coast of Izu O Shima Island. This route has been in service since January 2018. The purpose of this study is to validate the proposed method. First, the technical details of the method are described. An automatic identification system (AIS) observation was conducted before and after the implementation to validate the effectiveness of the recommended route for reducing collisions. The results show that the recommended route effectively reduces the risk of collisions. More specifically, the proposed method was found to be useful when establishing an effective recommended route.

Design of Fairway Width Based on a Grounding and Collision Risk Model in the South Coast of Korean Waterways

As a method of reviewing the design of new fairways and the redesign of existing fairways, we proposed a fairway design plan based on the collision and grounding probability, considering vessel traffic. A case study was conducted on the four traffic separation schemes (TSS) on the southern coast, which is the most complex coast among Korean coastal waters. The evaluation items of Korea’s Maritime Traffic Safety Assessment Scheme, the PIANC Guide, and the Port and Fishing Port Design Standards were all satisfied; however, some fairways had very high ship congestion at specific times, exceeding the fairway capacity. For each target fairway, the collision risk using the environmental stress (ES) model and the grounding risk using the IWRAP Mk II Model were analyzed. The grounding risk was found to be equally good, but the aggregation environmental stress (ESA) value, according to the ES model, was high in three fairways. The widths of the three fairways with high risk were partially expanded, and, thus, were re-evaluated. The overall ESA was reduced, and the psychological burden of operators due to the marine environment, such as the fairways, was significantly eased. Based on the results of this study, it would be beneficial to apply a design scheme using collision and stranded risk models when designing new fairways or reviewing existing fairways. An appropriate fairway design plan is prepared that, through further research using various evaluation models and techniques, could be useful in coastal waters in the future.

Testbed Scenario Design Exploiting Traffic Big Data for Autonomous Ship Trials Under Multiple Conflicts With Collision/Grounding Risks and Spatio-Temporal Dependencies

Autonomous ships are promoted as the future of the maritime transport industry aiming to overcome conventional vessels in terms of performance, safety and environmental impact. Yet their tangled cyber-physical-social interactions and new emerging properties induce questions regarding their liability and trustworthiness. Digital simulations and sea trials are launched to assure the safety requirements and social expectations are met a priori. This paper presents the design of realistic testbed scenarios from huge historical data through a high-performance computational method to recommend a complete set of navigation scenarios for autonomy tests. The developed approach integrates traffic big data from Automatic Identification System (AIS) with high-resolution digital maps, vessel information registry, and digital nautical charts. All historical vessel-to-ground and vessel-to-vessel interactions are efficiently analyzed through a hierarchical method for collision and grounding conflicts assessment with a 15-minutes prediction horizon. Relative risk is evaluated accurately over full periods of predicted close-quarters situations subject to physical limits and sea-room availability for evasive maneuverers under COLREG rules and traffic separation schemes. Spatial dependencies among multiple conflicts define risky momentary traffic situations modelled through directed graph representation of nested interactions. Their temporal dependencies describe navigation scenarios through dynamic co-behaviors between multiple participating vessels over a period of time. Finally, we analyze negative/positive actions that increase/decrease the complexity. The presented algorithms are computationally very efficient, they scale to several (country*year)s where millions of scenarios are extracted, classified, and scored by their relative risk, complexity, and likelihood for firm post-test conclusions.

The Role of Vessel Traffic Services in Traffic Separation Scheme

The transportation of goods, passenger and livestock by sea is growing rapidly and rise a need for safety, security and environment protection. Now Indonesia is in the process of implementing E-Navigation. But since E-Navigation is complex and need a lot of system interoperability, then Indonesia may start the implementation by introducing VTS (Vessel Traffic Services) as a system designed to achieve the highest level of safety at sea, increase fleet efficiency and simplify everyday tasks both ashore and on board and therefore the operations are processed seamlessly, the compliance is guaranteed and the workload and costs are optimized. The VTS is not only for vessel traffic management but it also for harbour cluster and integrating communication system among stake holders on ships and on shore. But VTS plays a very important role in maintaining safety of navigation and efficiency as well as environment protection in traffic separation schemes. Nowadays, the next generation of VTS so-called smart VTS is capable to monitor (collect and process the data, create common operational picture, distribute data to clients), alerting (analyse traffic, detect dangerous traffic situations, and increase situation awareness), and respond (active decision support services and ensure ship to shore communications). The respond, however, is similar with the smart marine technology that may reduce human error significantly. Indonesia hopefully will implement the 16 kinds of MS (maritime services) portfolio with smart VTS especially in maintaining safety, security, efficiency and environment protection in traffic separation schemes.

Fuzzy logic based dynamic decision-making system for intelligent navigation strategy within inland traffic separation schemes

This paper proposes a fuzzy logic-based intelligent decision-making approach for navigation strategy selection in the inland traffic separation scheme. The dynamic characteristics of navigation process, including free navigation, ship following and ship overtaking, are further analysed. The proposed model can be implemented in the decision support system for safe navigation or be included in the process of autonomous navigation. The decision-making model is achieved from the perception-anticipation-inference-strategy perspective, and the dynamic features of ships (i.e. speed, distance, and traffic flow) are comprehensively considered in the modelling process. From the results of both scenarios for overtaking and following, it illustrates that the timing is significant for strategy selection and should well consider the complex situation and ship behaviours, moreover, the proposed approach can be used for intelligent strategy selection.

Simplifying interactions between autonomous and conventional ships with e-Navigation

Ships in autonomous mode will for a long time interact with conventional ships with human decision-makers on the bridge. For safety it will be necessary to simplify this interaction and this paper discusses three areas which will be crucial in this respect: the collision regulations, e-navigation and traffic separation schemes. To be able to code collision avoidance algorithms COLREGS must be quantified. Soft enumerations like “good seamanship” needs to be made machine-readable. At the same time, such attempts threaten to make them less human-readable. On the positive side e-Navigation services like route exchange promises to make ship intentions more transparent and paired with an extended network of Traffic Separation Schemes future interaction between manned ships and ships in autonomous mode can be facilitated.

Traffic Rules and Environmental Conditions in Kattegat and the Sound Regarding Changes Planned for 2020

This paper describes presently applied sailing rules and environmental conditions on Danish waters such as Kattegat and the Sund. Those rules were established in late 70’s of the twentieth century by Danish authorities as Denmark is a coastal country and has the legal right to do so. Presently International Maritime Organization – IMO is in the process of approving a new set of routeing measures and traffic separation schemes which should comply with resolution A.257(14) – General provisions on ships’ routeing, and will be introduced by Organization.

IBS를 이용한 여수·광양항 통항분리 ZONE에서의 동선 조사

This study analyzed ship traffic using in IBS (Integrated Bridge System) in relation to the volume of traffic at traffic separation zone marine traffic on route to or from Yeosu-Gwangyang Port and examined the risk factors and countermeasures for marine transport safety management. As a result of marine traffic survey in Yeous-Gwangyang port for three days in October 2017, daily average passing ships were 411 ships, and about 65% of the total passing ships between 06:00 and 18:00. The volume of traffic in the traffic separation zone as an incoming and outgoing vessel were about 370 of the total vessels and accounted for about 30%. The Dangerous cargo carriers accounted for 58% of all vessels, 27% of general cargo vessels, 9% of containership and 6% of other vessels. As a result of VHF, general reports were the most common items with 65%, information provision were 19%, response ship communication were 11%, non-response and warning measures were 5%. It was found that many cargo ships and tanker vessels in the traffic separation zone encountered the most frequently when incoming and outgoing routes.BRConsequently, the safety traffic separation schemes are as follows; A vessel using a traffic separation schemes needs the active passing management system in the traffic separation zone, where the medium work ships incoming and outgoing in the specified areas including the costal traffic routes is urgently needed safety management for the passing routes of large ships.

To Cooperate or Not? Why Working Together is Essential in the Arctic

Abstract The Norwegian Arctic covers Svalbard, Bear Island, Jan Mayen and the Barents Sea. 80% of all shipping activities in the Arctic are within Norwegian territorial waters and the Exclusive Economic Zone. To reduce the risk for accidents, the Norwegian authorities have established several preventive measures. Among these are ship reporting systems, traffic separation schemes in international waters and surveillance capabilities. If an accident has occurred and an oil spill response operation must be organized - resources, equipment, vessels and manpower from Norwegian and neighboring states will be mobilized. In 2015, the Norwegian Coastal Administration finalized an environmental risk-based emergency response analysis for shipping incidents in the Svalbard, Bear Island and Jan Mayen area. This scenario-based analysis has resulted in a number of recommendations that are currently being implemented to be better prepared for oil spill response operations in the Norwegian Arctic. Further, a large national oil spill response exercise in 2016 was based on one of these scenarios involving at sea and onshore oil spill response at Svalbard. The 2016 exercise, working within the framework of the Agreement on Cooperation on Marine Oil Pollution Preparedness and Response in the Arctic between Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden and the USA (Arctic Council 2013), focused on a shipping incident in the Norwegian waters in the Barents Sea, close to the Russian border. Every year, as part of the Russian – Norwegian Oil Spill Response Agreement and the SAR Agreement in the Barents Sea, combined SAR and oil spill response exercises are organized. These are held every second year in Russia and every second year in Norway. There is an expected increased traffic and possible increased risk for accidents in the Arctic waters. In order to build and maintain an emergency response system to this, cooperation between states, communities, private companies and other stakeholders is essential. It is important that all actors that operate and have a role in the Arctic are prepared and able to help ensure the best possible emergency response plans. We depend on one another, this paper highlights some of the ongoing activities designed to strengthen the overall response capabilities in the Arctic.

Developing a Maritime Safety Index using Fuzzy Logics

Safe shipping is essential for society and different measures are taken to improve maritime safety, for example through implementation of traffic separation schemes, radar surveillance and traffic management concepts. But how can maritime safety be measured to determine the effects of those implementations? In this study, a real‐time maritime safety index for a ship is developed, taking into account both the probability of grounding and the probability of collision. The index is developed using fuzzy integrated systems and validated in ship handling simulator scenarios. It uses numerical data from the simulator as an input to assess the present traffic situation from the perspective of a specific ship and outputs a comprehensive index. This paper describes the concept of sea traffic management as proposed and evaluated in the EU funded STM Validation project, the motivation for developing a maritime safety index, the numerical input variables and model properties and also validates the feasibility of the approach.

Systems-Theoretic Process Analysis of Maritime Traffic Safety Management in the Gulf of Finland (Baltic Sea)

According to International Maritime Organization (IMO), the Baltic Sea Area has some of the densest maritime traffic in the world. The Baltic Sea was designated a Particularly Sensitive Sea Area (PSSA) at IMO Marine Environment Protection Committee's 53rd session in July 2005. The Mandatory Ship Reporting System in the Gulf of Finland Traffic Area (GOFREP) was established by IMO in 2003 and has been in operation since 2004. The objective of this study in progress is 1) to outline the hierarchical structure of the maritime navigation safety management system from European to ship onboard level and 2) to apply the Systems-Theoretic Process Analysis (STPA) to identify system level hazards and potentially unsafe ship speed and maneuvering control actions with respect to IMO Collision Regulations (COLREGs) Rules on ship safe speed, ship safe separation distances and the Traffic Separation Schemes requirements with the aim of evaluating the effective hazard control options to enable efficient updating of ship level situational awareness and the enforcement of safety constraints in real time.

DESIGNING AND MODELLING COAST MANAGEMENT GIS FOR BOSPHORUS

Web based geographic information systems (GIS) has great potential based on developments in internet and web technology. Web based GIS is a network based tool that takes advantage of internet with visualizing, analysing and accessing of distributed data and analysis functions. With the length of 30 kilometres, the Bosphorus provides an essential zone that offers great maritime traffic services. This shipping way which connects The Black Sea and The Mediterranean Sea through The Marmara Sea, has no alternative and it is substantial for economies of Black Sea countries. The Bosphorus is one of most important natural straits in the world handling 150 transit ships, 23 freighters with dangerous cargo and 2500 local transport ships with 2 million passengers on daily basis. In this study, it is aimed to create a web based GIS application for an effective coast management which includes berthing factors (anchorage areas, currents, submerged, etc.), maritime traffic factors (traffic separation schemes, traffic flow directions), closed areas and other factors (lighthouses, buoys, beacons, etc.) by digitizing printed navigation charts produced by Turkish Naval Forces, Office of Navigation, Hydrography and Oceanography.

DESIGNING AND MODELLING COAST MANAGEMENT GIS FOR BOSPHORUS

Abstract. Web based geographic information systems (GIS) has great potential based on developments in internet and web technology. Web based GIS is a network based tool that takes advantage of internet with visualizing, analysing and accessing of distributed data and analysis functions. With the length of 30 kilometres, the Bosphorus provides an essential zone that offers great maritime traffic services. This shipping way which connects The Black Sea and The Mediterranean Sea through The Marmara Sea, has no alternative and it is substantial for economies of Black Sea countries. The Bosphorus is one of most important natural straits in the world handling 150 transit ships, 23 freighters with dangerous cargo and 2500 local transport ships with 2 million passengers on daily basis. In this study, it is aimed to create a web based GIS application for an effective coast management which includes berthing factors (anchorage areas, currents, submerged, etc.), maritime traffic factors (traffic separation schemes, traffic flow directions), closed areas and other factors (lighthouses, buoys, beacons, etc.) by digitizing printed navigation charts produced by Turkish Naval Forces, Office of Navigation, Hydrography and Oceanography.

Navigators’ Behavior in Traffic Separation Schemes

One of the areas of decision support in the navigational ship conduct process is a Traffic Separation Scheme. TSSs are established in areas with high traffic density, often near the shore and in port approaches. The main purpose of these schemes is to improve maritime safety by channeling vessel traffic into streams. Traffic regulations as well as ships behavior in real conditions in chosen TSSs have been analyzed in order to develop decision support algorithms.

THE REQUIREMENTS FOR SAFE TRAFFIC AND MANOEUVRING IN APPROACHES TO THE PORT OF ŚWINOUJŚCIE AND THE OUTER PORT OF ŚWINOUJŚCIE WITH PARTICULAR EMPHASIS ON LNG VESSELS

This paper presents an overview of the most important requirements and recommendations of international organizations for the area of LNG terminal under construction in winouj cie. These recommendations should be considered when planning safe traffic and manoeuvring of ships in port approaches to the Port of winouj cie and to the Outer Port of winouj cie. The approach area to the new terminal is located on shallow waters. Up to the present moment the fairway, anchorages and seamarks have been used by vessels of smaller size. After the construction of the new port with an LNG terminal it will handle the greatest LNG carriers. To ensure their safe entrance to the port, the fairway should be prepared with sufficient width and depth, with navigational aids. It is also necessary to prepare appropriate emergency anchorages and places where the vessels can return in case further voyage is dangerous. Additionally LNG cargo is very dangerous, because of this there is a compulsory to introduce of the highest safety standards, both in the design of the approach area and the application procedures for ships traffic. In particular, fairways and port canals, Under Keel Allowance, air draft, turning basin, vessel traffic services (VTS), traffic separation schemes (TSS), moving safety zone, and required speed limit are presented in the paper.

The development of ships׳ routeing measures in the Bering Strait: Lessons learned from the North Atlantic right whale to protect local whale populations

As a precautionary measure to protect the culturally-significant bowhead whale (Balaena mysticetus) from vessel strike, this paper explores the potential for having the International Maritime Organization endorse ships׳ routeing measures in the Bering Strait region. The confined nature of the Bering Strait forces both vessel traffic and the migrating Bering–Chukchi–Beaufort stock of bowhead whales to occupy the same narrow space, thus putting individual animals at risk of vessel strike. The potential for vessel strike may become exacerbated as the reduction of Arctic sea ice makes the Arctic increasingly accessible, allowing vessels to transit through the Strait in greater densities. In drawing from lessons learned in the successful reduction of vessel strike to the North Atlantic right whale (Eubalaena glacialis), the author provides broad recommendations for implementing ships׳ routeing measures in the Bering Strait region based on findings by Citta et al. (2012). It is recommended that both the western side of Big Diomede Island and the western side of St. Lawrence Island be designated as seasonal Areas To Be Avoided (ATBA) during fall months when bowheads are known to inhabit the area. Alternatively, it is proposed that Traffic Separation Schemes (TSSs) be implemented so that vessels must keep to the eastern side of both Big Diomede Island and St. Lawrence Island during this time. Both measures would reduce the amount of overlap between migrating bowhead whales and transiting vessel traffic, effectively reducing the potential for vessel strike.

Use of AIS Data to Characterise Marine Traffic Patterns and Ship Collision Risk off the Coast of Portugal

This paper studies the risk of ship collision off the coast of Portugal based on Automatic Identification System (AIS) data, which is recorded and maintained by the Portuguese coastal Vessel Traffic Service (VTS) control centre (CCTMC). Computer programs for decoding, visualization and analysis of the AIS data have been developed. From analysis of the AIS data available, maritime traffic off the coast of Portugal is characterized and a statistical analysis of traffic in the Traffic Separation Schemes is provided. An algorithm has been developed to assess the risk profile and the relative importance of routes associated with ports. A method is proposed to calculate the collision risk from the assessment of the number of collision candidates by estimating future distances between ships based on their previous positions, courses and speeds, and comparing those distances with a defined collision diameter. Values of causation probability suggested in several studies are used to calculate the expected number of collisions in the period of time under investigation based on the number of collision candidates. The results of this study are then compared with the number of collisions that have occurred between 1997–2006, registered and maintained by the Portuguese Maritime Authority.

Evolutionary Ship Track Planning within Traffic Separation Schemes – Evaluation of Individuals

The paper presents an extended version of the author’s Evolutionary Sets of Safe Ship Trajectories method. The method plans safe tracks of all ships involved in an encounter including speed reduction maneuvers, if necessary, and taking into account Rule 10 of COLREGS, which specifies ships’ behavior within Traffic Separation Schemes governed by the International Maritime Organization (IMO). The paper focuses on the evaluation phase of the evolutionary process and shows how fitness function is designed to compare various possible tracks as well as to assess the quality of a final solution. The impact of the fitness function on the method’s results is illustrated by examples.