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Traffic Density Mapping Service (TDMS)


The use of Traffic Density Maps (TDM) is a simple and effective way to show vessel movement patterns which contribute to a better understanding of maritime traffic and help to answer important questions, such as where are the main shipping lanes, by who are they used, and which ship types are navigating on which route. The TDM are produced by compiling ship’s positioning data, and can highlight the presence of congested areas. The TDM can be used for different purposes including risk assessments and traffic planning.

Traffic Density Mapping Service

EMSA received several requests from Member State authorities, EU Institutions and other bodies for the provision of ship positioning data (mainly AIS and LRIT) in order that they can produce TDM. The issue was discussed at the HLSG 2 meeting (Brussels 20 June 2017) where several questions were posed by the Member States. The HLSG agreed “on mandating EMSA to start preparing for providing traffic density maps, based on AIS data, to interested parties upon request, as a new service and then report back to the next HLSG.”

In the past, EMSA produced TDM in response to ad hoc requests in order to complement specific studies or projects. Following the HLSG mandate for EMSA to develop a tool/service to generate TDM, the Agency contacted several Member State Authorities, EU Institutions and research bodies which have prior experience in developing TDM, as well as users who expressed their interest in a TDM service.

EMSA plans to develop a tool to automatically generate vessel density maps using ship positioning data collected from T-AIS and S-AIS data sources, on the basis that the existing maritime infrastructure and application environment of the SafeSeaNet Ecosystem Graphical Interface (SEG) would be used to develop a TDM web service. The service will be developed gradually, taking into account the possibilities offered by the technology and the user requirements.

There is no international standard definition or method to create TDM. However, most methodologies are based on grid-based approaches, whereby the area to be monitored is divided into cells in order to create a spatial grid. The methodology proposed by EMSA for traffic density plotting is based on calculating of the number of routes recorded for a specific ship within a specific cell of the grid during a specified time period. EMSA will present the proposed methodology to the HLSG for approval. Once the HLSG approves the methodology, the conditions for developing a TDM service will be assessed and the implementation roadmap will be defined.

Based on the proposed methodology, EMSA has produced samples of TDM by period, area and ship type, and users can access the TDM samples using the links below. The TDM samples will be updated.

These maps are constructed using T-AIS and S-AIS data collected on 11th August 2017 (data from one full day), with the exception of the Black Sea TDM, which shows the traffic density using one week of data (11-17th August 2017).

Baltic Sea All data data of 11.08.17Baltic Sea – All ship types (11 August 2017)
Baltic Sea Cargo multi data of 11.08.17Baltic Sea – Cargo ships (11 August 2017)
Baltic Sea Passenger data of 11.08.17Baltic Sea – Passenger ships (11 August 2017)
Black Sea All data data of 11 17.08.17Black Sea – All ship types (11-17 August 2017)