European Railway Agency - ERA

Making the railway system work better for society.

Technical Specifications for Interoperability

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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.

How do TSIs relate to national rules?

National rules only apply in the following circumstances:

  • Technical compatibility (to ensure technical compatibility with the legacy rail system where it is not designed and built to TSIs)
  • Specific cases (where special provisions in the TSIs, either temporary or permanent, are needed for any part of the rail system)
  • Open points (where a national rule provides a solution for the open point).

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.

This TSI concerns the energy subsystem and covers all fixed installations necessary to achieve interoperability that are required to supply traction energy to a train.

This TSI covers:

  • The infrastructure structural subsystem (line layout, track parameters, switches and crossings, platforms, track resistance to applied loads, structures resistance to traffic loads, immediate action limits on track geometry defects etc.);
  • The part of the maintenance functional subsystem relating to the infrastructure subsystem (i.e. washing plants for external cleaning of trains, water restocking, refueling, fixed installations for toilet discharge and electrical shore supplies).

This TSI concerns the rolling stock subsystem and applies to the following types of rolling stock:

  • Self-propelling thermal or electric trains;
  • Thermal or electric traction units;
  • Passenger carriages;
  • Mobile railway infrastructure construction and maintenance equipment.

The revised TSI for the onboard and trackside CCS subsystems adopted by Commission Regulation (EU) 2016/919 (Corrigendum) amends this Regulation relatively to the index No 1 in Table J.2 of Appendix J.

Decision 2008/232/EC continues to apply for noise and crosswind requirements under the conditions set out in point and of the Annex to this Regulation.

For noise requirements, the application of Regulation 1304/2014/EU from 1 January 2015 supersedes Decision 2008/232/EC.

This TSI concerns the rolling stock subsystem and applies to freight wagons including vehicles designed to carry lorries.

This TSI concerns the control command and signalling, infrastructure, energy, operation and traffic management, and rolling stock (locomotives and passenger units) subsystems. It applies to new, renewed and upgraded tunnels which are located on the rail network of the European Union.

By definition, a railway tunnel is an excavation or a construction around the track provided to allow the railway to pass for example higher land, buildings or water. The length of a tunnel is defined as the length of the fully enclosed section, measured at rail level. A tunnel in the context of this TSI is 0.1 km or longer. Where certain requirements apply only to longer tunnels, thresholds are mentioned in the relevant clauses of the TSI.

This TSI concerns the control command and signalling on-board and trackside subsystems. It applies to control-command and signalling on-board subsystems of vehicles which are (or are intended to be) operated on and control-command and signalling trackside subsystems of the rail network of the European Union.

Different ERTMS baselines, as specified in Annex A to TSI CCS, may coexist together in vehicles and trackside equipments:

  • ETCS baseline 2 and GSM-R baseline 1
  • ETCS baseline 3 maintenance release 1 (MR1) and GSM-R baseline 1, correcting numerous errors in ETCS baseline 2 and adding new functionalities
  • ETCS baseline 3 release 2 (R2) and GSM-R baseline 1, with the inclusion of EGPRS (GPRS with mandatory EDGE support) in the GSM-R specification and the correction of errors to ensure backwards and forwards compatibility with ETCS baseline 3 MR1.

Backwards compatibility is also provided between vehicles equipped with ETCS baseline 3 and tracskide equipped with ETCS baseline 2. More info on backwards and forwards compatibility of ETCS baselines.

The mandatory ERTMS specifications (e.g. Subset-026) for the corresponding baseline and release (as set out in Annex A of TSI CCS) are available here.

The informative ERTMS specifications for the corresponding baseline and release are available here.

A generic ETCS driver’s handbook is available here.

The ERTMS specifications are managed according to the ERA Change Control Management (CCM).

ERA is responsible to identify all errors that potentially could not allow the system to provide a normal service and to publish as early as possible the respective solutions to correct them as well as the evaluation of their impact in the compatibility and stability of the existing ERTMS deployment. More info on error corrections of current ETCS baselines.

In order to facilitate transparency and interoperability between the different sets of specifications laid down in the CCS TSI, ERA has assessed, together with the sector, the compatibility between ETCS baselines.

This TSI applies to the operation and traffic management subsystem of infrastructure managers and railway undertakings related to the operation of trains on the rail system of the European Union. It covers those elements of the rail operation and traffic management, where principally there are operational interfaces between railway undertakings and infrastructure managers and where there is a particular benefit to interoperability. This entails traffic planning and management, train composition, train braking, train visibility, data recording, degraded operation etc.

The Commission has published the latest version of the TSI OPE under regulation 2019/773. This replaces Regulation 2015/995. However, it is important to consider the various transitional dates, which apply - see below. Therefore, Regulation 2015/995 will continue to apply in part until 16th June 2024 when it will be completely replaced.

Transitional dates:

  • New OPE TSI applies from 16 June 2021 (2 years transition);
  • Section and appendix D1 apply from 16 June 2019 or 16 June 2020, depending on the implementation of Interoperability Directive in the single Member States; and
  • Appendices A and C apply from 16th June 2024 at the latest (5 years transition).

In accordance with Article 9 of Directive (EU) 2016/798, the RU and IM shall ensure compliance with this Regulation under their respective Safety Management System (SMS).

Furthermore, the changes of process and responsibilities brought by Article 23 of Directive (EU) 2016/797 and by Section and Appendix D1 of the Annex to this Regulation should be managed by the railway undertakings and where appropriate the infrastructure managers, through their respective SMSs.

Moreover, railway undertakings should apply for an update of their safety certificates in accordance with Article 10(13) of Directive (EU) 2016/798 of the European Parliament and of the Council, if due to Article 23 the type or the extent of its operations are substantially altered, or a safety certification body so requires in accordance with Article 10(15) of Directive (EU) 2016/798.

RUs who need to replace their safety certificate during this time should seek, where necessary, further information from the relevant certification body (ERA or NSAs).

This TSI concerns the telematics applications subsystem and applies to applications for passenger services, including systems providing passengers with information before and during the journey, reservation and payment systems, luggage management and management of connections between trains and with other modes of transport.

The reference data (company codes, location codes) can be found in the TAF/TAP TSI reference data portal.

Technical documents

The technical documents, including the different baselines and reference files, are available here.


The Co-operation Group for the Implementation of Telematics Applications for Passengers assesses the TAP TSI implementation in cooperation with National Contact Points (NCPs) in Member States and with Representative Bodies (RB):

This TSI concerns the telematics applications subsystem and applies to applications for freight services, including information systems (real-time monitoring of freight and trains), marshalling and allocation systems, reservation, payment and invoicing systems, management of connections with other modes of transport and production of electronic accompanying documents.

The reference data (company codes, location codes) can be found in the TAF/TAP TSI reference data portal.

Technical documents

The technical documents, including the different baselines, reference files and compliance reports, are available here.


The Co-operation Group for the Implementation of Telematics Applications for Freight assess the TAF TSI implementation in cooperation with National Contact Points (NCPs) in Member States, different Representative Bodies (RB) via the Joint Sector Group (JSG) and, when necessary, with the Corridor Managers: