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Technical Specifications for Interoperability (TSIs)

The Technical Specifications for Interoperability (TSIs) define the technical and operational standards which must be met by each subsystem or part of subsystem in order to meet the essential requirements and ensure the interoperability of the railway system of the European Union.

New in July 2025

The Agency, via its ERA Academy, in cooperation with the Fixed Installations & Rolling Stock Unit, has prepared a comprehensive e-learning course that provides insights to the Technical Specifications for Interoperability (TSIs).

Interoperability (its concept and chronological railway packages), TSI’s content and structure together with conformity assessment, EU standards and national rules are now explained through this online course which is available free of charge. There is no need to register, and the course can be consulted any time at the leisure of the user. 

Join this self-discover journey through the basic principles of what interoperability means, the purpose of a harmonised standard in respect to essential requirements and description of structural and functional TSIs. 

Enter the World of TSIs

This course is aimed at professionals from all backgrounds mostly focused on users that are or will be working in this domain of expertise. 

Course Level: Entry Level

The Technical Specifications for Interoperability (TSIs) define the technical and operational standards which must be met by each subsystem or part of subsystem in order to meet the essential requirements and ensure the interoperability of the railway system of the European Union.

Directive (EU) 2016/797 defines the subsystems, either structural or functional, forming part of the railway system of the European Union.

For each of those subsystems, the essential requirements need to be specified and the technical specifications determined, particularly in respect of constituents and interfaces, in order to meet those essential requirements. The essential requirements can be summarised as safety, reliability and availability, health, environmental protection, technical compatibility and accessibility.

Recommendations For Use

Recommendations For Use (RFUs) are prepared by the coordination group of the notified bodies (NB-Rail). The RFUs record questions, doubts or concerns about a specific TSI content or some aspects regarding its application together with a common solution/interpretation. They are used in conjunction with the provisions of the TSIs by all notified bodies under Directive (EU) 2016/797.

RFUs are not intended to change the text of a TSI or any other European legislation but are proposed to provide a common understanding on relevant issues or parts of a legal text. The complete list of RFUs can be found on the NB-Rail website.

Deficiencies in TSIs

The TSIs should be revised at regular intervals, especially to remedy deficiencies.

Deficiencies in TSIs are textual errors, omissions, mistakes in translation or in technical content, or other inconsistencies as referred to in Article 6 of Directive (EU) 2016/797. You can find deficiencies in TSIs already adopted and published in the Official Journal of the European Union. However, you cannot find deficiencies in the TSIs which are still in the process of being drafted by ERA or in any following approval step.

The management of deficiencies in the TSIs does not concern the evolution of the technical documents published by the Agency and referred to in the TSIs. Similarly, the process does not cover the Change Control Management for the ERTMS specifications and documents listed in Annex A of the TSI on control command and signalling.

Related documents

TSIs general application guide 2023

English (1.26 MB - PDF)
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TSIs chronology table

English (300.93 KB - PDF)
View

TSI deficiencies

English (145.44 KB - XLSX)
Download

TSI deficiencies - archive

English (962.49 KB - PDF)
View

Task force on the winter performance of composite brake blocks

English (2.33 MB - PDF)
View

Standards quoted in TSIs

English (73.72 KB - XLSX)
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