Mobility and Transport


ERTMS - Specifications and Legislation

ERTMS - Specifications and Legislation

ERTMS legislation mainly covers two aspects of the system: technical description and the process for putting it into service. In addition to these core legislations there is also additional legislation, which is related to the use of ERTMS.   

The following figure gives an overview of the scope of the main legislation directly related to ERTMS enforced at a European level.  

On a hierarchy scale, the highest documents related to Interoperability in the Railway frame are the EC Directives. Below there are EC Decisions that develop essential and technical requirements in more depth.

The Interoperability Directive (2008/57/EC) is currently in force, and sets out a number of essential requirements to be met for interoperability, which include safety, reliability and availability, health, environmental protection and technical compatibility along with others specific to certain sub-systems. The Directive also requires the production of mandatory Technical Specifications for Interoperability (TSIs).

The procedure for putting ERTMS systems into service is defined in the Interoperability Directive and has been further explained in an EEC recommendation, 2014/897/EC (i.e. DV 29 bis)

The Technical Specifications of Interoperability for Control Command and Signalling ( TSI CCS ) Commission Regulation (EU) 2016/919 is the legal basis of ERTMS specification. It includes the definition of the essential requirements, the subsystem and interface functional and technical specifications, and also determines the necessary list of constituents and interfaces and procedures for their assessment. From the legal point of view, it is a Commission Regulation, thus directly applicable to all actors without a transposition to the national law. This also means that any actor can use the national courts to enforce this Regulation.

An application guide for this TSI is available on the following link, Application guide for TSI  

Annex A of the CCS TSI, includes the list of “subsets,” which contain the ERTMS system requirement specifications and functional description between its different constituents. This Annex A of the CCS TSI contains two sets ( #1 and  #2 and #3) of technical specifications for ERTMS that can be applied to the projects. Contained in each of the sets of technical specifications, are two types of documents:

  • Mandatory specifications, which must be fulfilled by any ERTMS system, subsystem or component in order to achieve interoperability. Any deviation from the specifications must be transparently identified and its potential impact on interoperability will be assessed.
  • Optional specifications that provide additional recommendations for the definition of the ERTMS subsystems

The System Required Specifications (SRS) is one of the specific technical requirements stated in Annex A. It is called “SUBSET-026” and it is the main document containing all the detailed technical specifications of the ERTMS system.

The European Railway Agency (ERA) , as ERTMS system authority, is in charge of the management, change and production of the specifications related to the ERTMS.