While Article 4 of Directive (EU) 2016/797 sets out the content and some general objectives of the technical specifications for interoperability (‘TSIs’), that Directive does not set out the specific objectives for each TSI but empowers the Commission to adopt delegated acts for that purpose.

This Decision sets out a coherent set of specific objectives which should be integrated in the TSIs to improve interoperability while making it possible to facilitate, improve and develop rail transport services within the Union and with third countries and contribute to the completion of the single European railway area and the progressive achievement of the internal market.

Those specific objectives in the TSIs should be implemented by means of requests to the European Union Agency for Railways (the ‘Agency’) in accordance with Article 5(2) of Directive (EU) 2016/797. Those requests should be based on the Commission's own priorities and on the availability of resources within the Agency. For each specific objective, the recommendations of the Agency should include cost benefit analyses and impact assessments of the technical solutions considered to allow the Commission to select the most viable solutions and establish the TSIs by means of implementing acts according to the examination procedure referred to in Article 51(3) of Directive (EU) 2016/797.

In terms of scope of application, the existing TSIs satisfactorily cover all subsystems defined in Annex II to Directive (EU) 2016/797. However, in line with ‘better regulation’ principles, in order to reduce the number of legislative acts and in order to further increase the coherence between TSIs, the scope of specific TSIs should be reviewed and possibly some of them should be restructured or merged to avoid duplication and to provide a more direct correspondence between subsystems, essential requirements and TSIs. That should take into account the stability necessary in railway legislation.

In order to ensure coherence of the legislation, the possible impacts and interfaces between TSIs and between TSIs and existing strategies, policies and legislation should be taken into account. It should also be considered whether the proposed solutions, or specific elements, should be included in the TSI itself or in related documents and legislation. Furthermore, the TSIs should, whenever possible, preserve the TSI provisions which remove technical barriers to interoperability, in particular provisions facilitating the free movement of vehicles throughout the Union.

TSIs revisions should take into account the experience of the railway sector regarding unclear requirements or other unintended impacts and costs resulting from the TSIs, including in particular the experience of Rail Freight Corridors or experiences resulting from the application of the TSIs to low density lines.

TSIs revisions should also take into account the need to achieve the right balance between a rule-based approach, which allows to facilitate technical compatibility in particular at the interfaces between subsystems, but also between interoperability constituents and subsystems, and a risk-based approach, which allows to facilitate technical progress and innovative solutions, in particular when specifying functions and performances.

TSIs revisions should take into account the developments of the railway system and related research and innovation activities, in particular but not limited to Shift2Rail, keeping the margin of manoeuvre for innovation, and integrating innovations when they reach an appropriate level of maturity determined by the Agency.

In terms of the technical coherence of the 1 520 mm track gauge railway networks in the Union and of vehicles operated on those networks, relevant TSIs should take into account the evolution of technical requirements applicable in the 1 520 mm track gauge networks of third countries.

In order to facilitate their promotion and possible adoption outside the Union, and to facilitate interchange between third country networks and the Union, TSIs may include voluntary provisions taking into account requirements common in other geographical areas, for example higher axle loads for heavy trains.

In order to allow TSIs to keep up with developments in standards and other technical documents, TSIs should integrate references to those documents in a way which makes it possible to update them in a timely manner while providing for the necessary transitions between standards or between versions of standards.

In accordance with Article 4(3)(f) of Directive (EU) 2016/797, most TSIs include clauses defining the strategy for their application in order to make a gradual transition from the existing situation to a situation of compliance with the TSI. There is however confusion in the rail sector on the concrete application of those clauses. The strategies for application should thus be reviewed and, to the extent possible and depending on the nature of each TSI, be simplified and be consistent in the various TSIs, especially the TSIs relating to rolling stock. The possibility to allow a mixed application of a TSI and of its previous version during the transition period should be considered. Additionally, the validity period of the certificates for interoperability constituents and subsystem should be defined in the TSIs, and should be coherent between TSIs.

Article 4(3)(h) of Directive (EU) 2016/797 allows TSIs to include provisions applicable to existing subsystems and vehicles, in particular in the event of their upgrading and renewal. Those provisions can give rise to legal uncertainty in case of authorisations which are already issued, therefore there should be particular attention to the preliminary analysis of the related costs and benefits and to the definition of the modification works which require an application for a new authorisation.

In order to ensure efficiency in the processes of placing on the market and placing in service of vehicles, the TSIs should provide certainty as to which parameters of a vehicle should be checked as part of the authorisation procedures in accordance with Articles 21 and 24 of Directive (EU) 2016/797 and which parameters should be checked by the railway undertakings after the delivery of the vehicle authorisation for placing on the market and before the first use of the vehicle to ensure compatibility between vehicles and the routes on which they are to be operated. The TSIs should also clarify the procedures to be followed by the railway undertakings to ensure compatibility between complete trains, including intermodal transport units, and the routes on which they are to be operated as well as, to the extent possible, the information to be provided by the infrastructure managers and the conditions under which railway undertakings should be granted network access to carry out related tests.

In addition to the requirements of Article 5(2)(a) of Directive (EU) 2016/797 on the identification of basic parameters and of interfaces between subsystems, the tables of the TSIs listing the links between the basic parameters and the essential requirements set out in Annex III of Directive (EU) 2016/797 should also be updated in order to ensure a coherent approach among all TSIs.

In order to enable easy substitution during maintenance, to allow for economies of scale and to reduce maintenance costs and obsolescence, the modularity of the railway system should be improved. To that end, the number of interoperability constituents should be reviewed and increased where suitable, thereby encouraging the use of commercial off-the-shelf products and spare parts and reaping the benefits of standardisation.

The notification of conformity assessment bodies places significant administrative burden on the Member States and the Commission. In order to increase efficiency and reduce delays, a simplified process should be proposed for additional notifications if only limited or no additional competences are required from a conformity assessment body that has already been notified for a previous version of a TSI. In order to avoid uncertainty, each TSI should specify whether the full process for notification is to be followed or whether notification can be automatically extended to the revised TSI or a simplified process can be applied and under which conditions.

Since in some cases the description of the roles and responsibilities between applicant and notified bodies is not precise enough, leading to confusion and to divergent interpretations and implementation of the procedures for conformity assessment of interoperability constituents and subsystems, those procedures should be reviewed and the Commission should in parallel adopt implementing acts revising the ad hoc modules for conformity assessment, in line with Article 24(6) of Directive (EU) 2016/797. Additionally, the range of modules allowed for each interoperability constituent and subsystem should be revised and, if possible, streamlined in order to improve the efficiency of the process and to avoid unnecessary costs.

When considering possible solutions to safety-related issues, all possible causes of those issues should be considered, including, to the extent possible, those linked to security incidents, for example passenger safety in the aftermath of an explosion.

The European Railway Traffic Management System (‘ERTMS’), the telematics applications for passengers (‘TAP’) and the telematics applications freight (‘TAF’) are the backbone of railway digitalisation. Therefore, the relevant TSIs should be amended where appropriate to support the digitalisation of the railway sector.

Several TSIs still have open points. Those open points are elements that correspond to essential requirements and thus require harmonisation, but are not yet covered by the TSIs in question. Therefore, those open points should be addressed in order to reduce the number of national rules, with the objective to achieve full interoperability and contribute to the functioning of the single market.

In line with Article 6 of Directive (EU) 2016/797, TSIs are to be amended if it appears that they have deficiencies.

In order to adjust a discrepancy resulting from a revision of the WAG TSI, the NOI TSI should include a noise test of composite brake blocks to address rail freight noise, including where necessary through trackside monitoring or, if possible, through acoustic testing of composite brake blocks on a bench test.