Technical Specifications for Interoperability

A Technical Specification for Interoperability (abbreviated as TSI) is a text provided for in European Directive 2016/797^[1] adopted by the European Parliament and the Council of the European Union on the interoperability of the European rail system in accordance with the ordinary legislative procedure.

This directive stipulates that the railway system is divided into 8 subsystems:

1. infrastructure
2. Traction energy
3. control command and the trackside signalling
4. control command and the on-board signalling
5. rolling stock
6. Traffic operation and management
7. Maintenance
8. Telematic applications for passenger and freight services.

It also provides that a technical specification for interoperability (TSI) is drawn up for each subsystem.

These TSIs define the essential requirements of the above-mentioned European directives for specific cases and define a set of technical requirements that apply to new subsystems put into service.

These requirements constitute a set of conditions necessary for putting into service, but these conditions are generally not sufficient to guarantee safety, so they must be supplemented by some additional measures. They do not cover all the fields of the regulatory requirements, but for the fields they cover, they prevail over the national texts.