European Railway Agency - ERA

Making the railway system work better for society.

European Rail Traffic Management System (ERTMS)

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The European Rail Traffic Management System (ERTMS) is a single European signalling and speed control system that ensures interoperability of the national railway systems, reducing the purchasing and maintenance costs of the signalling systems as well as increasing the speed of trains, the capacity of infrastructure and the level of safety in rail transport.

ERTMS comprises of the European Train Control System (ETCS), i.e. a cab-signalling system that incorporates automatic train protection, the Global System for Mobile communications for Railways (GSM-R) and operating rules.

Technical specifications for ETCS and GSM-R are published in the Control Command and Signalling (CCS) Technical Specification for Interoperability (TSI).

GSM-R provides voice communication for train drivers and signallers and provides data communication for ETCS. ERTMS and GSM-R rules are published in the Operation and Traffic Management TSI.

ERA plays the role of system design authority for ERTMS. In that respect, it must establish a transparent process to manage, with the contribution of the sector’s representatives, any system changes

Quick Access to the ERTMS Specifications

CCS TSI Annex A – Mandatory specifications

CCS TSI Application Guide – Informative specifications

link to ERTMS specifications  


The Agency, in collaboration with the experts of the Sector organizations, has carried out the analysis and assessment of the CR in the database that can be considered as errors in the system specifications, with a view to identify those errors which could prevent the system to provide normal service according to Article 10 of the Commission Regulation (EU) No 2016/919. This opinion supersedes and replaces the opinion ERA/OPI/2017-2.

The results of this work is presented in this Opinion ERA/OPI/2020-2

Related documents

A first baseline compatibility assessment undertaken by the sector (UNIFE/UNISIG and ERTMS Users Group) has checked the compatibility between ETCS baseline 3 MR1 and ETCS baseline 2 (release 230d).

First baseline compatibility assessment

Within the scope of this assessment and provided that its recommendations are taken into account, the ETCS baseline 3 MR1 is backwards compatible with ETCS baseline 2.

A second baseline compatibility assessment has checked that:

  • ETCS baseline 3 R2 is fully backward/forward compatible with ETCS baseline 3 MR1
  • Both the backward compatibility between ETCS baseline 3 R2 vehicles and ETCS Baseline 2 trackside and the compatibility between ETCS baseline 3 R2 trackside operated with system version X=1 (i.e. ETCS Baseline 3 R2 trackside using only baseline 2 functions) and ETCS baseline 2 vehicles.

The second baseline compatibility assessment also includes the analysis of the compatibility between trackside and onboard both within ETCS baseline 3 MR1 and within ETCS baseline 2, in the light of the problem description of the Change Requests included in ETCS baseline 3 R2.

This second baseline compatibility assessment confirms that the ETCS baseline 3 R2 is fully backwards and forwards compatible with the ETCS baseline 3 MR1, i.e. that ETCS baseline 3 R2 vehicles can run a normal service on ETCS baseline 3 MR1 trackside and ETCS baseline 3 MR1 vehicles can run a normal service on ETCS baseline 3 R2 trackside.

ERA organises and processes the Change Control Management (CCM) for the ERTMS specifications and related documents listed in Annex A of the Control Command and Signalling (CCS) Technical Specification for Interoperability (TSI).

A CCM procedure exists under the ERA Integrated Management System. This procedure is based on the former procedure originally approved by the ERTMS Control Group and takes account of the return of experience accumulated over the past years.

Any modification to the ERTMS specification is analysed via a Change Request (CR). CRs can only be submitted in the CCM tool by the representative bodies. More information about the submission of CRs can be found in the restricted ERTMS area.

The use of some ETCS variables requires co-ordination, including the definition of who is assigning new values. Care has to be taken not to assign identical values for different purposes or vice versa. Reasons for this may be functional or safety related.

Based on the functionality behind each variable, a list for the organisations responsible for assigning values to them has been established (see section of Subset-054) and can be classified as follows:

  • For variables which need international co-ordination, ERA maintains public tables allocating unique values or range of values to the requesting organisations
  • For variables which need national co-ordination, the Member States are responsible for assigning unique values.

For ETCS variables, whose values assignment is under the coordination of ERA, fill in the related form and send it back to us by e-mail

Acknowledging the lack of a harmonized manual for the use of ETCS, ERA developed a generic ETCS driver’s Handbook to address the needs of the users. This Handbook concerns baseline 3 On-board Units (OBUs), i.e. those applying sets of specifications #2 and #3 of CCS TSI Annex A (2.3.0d OBUs are not in scope as the Driver Machine Interface is not harmonized under set of specifications #1).

The Handbook covers both B3 software versions (SRS 3.4.0 and SRS 3.6.0), all possible system versions X.Y, all operating levels, modes, OBU options and screen technologies.

It is provided in open-source MS Word and HTML versions, in English, French and German.

This Handbook is meant to serve the following uses (indicative list):

  • Be a reference user’s manual for all possible configurations of B3 OBUs;
  • Be used to derive dedicated drivers’ manuals for specific OBU implementations in specific rolling stock types;
  • Constitute a comprehensive harmonized tutorial for drivers’ training purposes;
  • Serve to elaborate questions for drivers’ competence certification;

When using the MS Word version of the Handbook for a specific rolling-stock type fitted with a specific ETCS OBU, it is advisable to customize it so that only information relevant to that specific configuration is provided to the user. Such customization can be carried out by applying the instructions contained in the Customization Guide.

Users can also complement the Handbook with additional information concerning the specific rolling stock on which the OBU is installed, potential Class B system instructions or applicable company rules. Advice on how to do so while respecting the overall coherence of the Handbook is also included in the Customization Guide.

An HTML Guide is equally provided explaining how to download, configure and use the HTML version in a digital medium (e.g. a tablet). This version may either be configured by the end users themselves or be customized before being handed over to them; both options are equally covered in the Guide.

It is underlined that the Handbook contains no new specifications compared to the existing CCS TSI and OPE TSI; it only extracts out of the existing specifications those parts that are relevant to the driver and present them to him/her in a concise and user-friendly manner.

The generic ETCS driver’s Handbook has been compiled by INECO SA under a contract with ERA, with guidance from the operational experts of the ERTMS Operational Harmonization (OH) workgroup of ERA.

Although every effort has been made to eliminate all errors, some may still persist. Users are prompted to report to ERA such occurrences or other suggestions for improvement.

Articles 13 and 14 of Interoperability Directive define the cases where national rules (NRs) can be notified ant the procedure of notification of national rules by Member States.

The applicable NRs for vehicle authorization are recorded in IT tool RDD. In particular, rules for ETCS and GSM-R are listed in section 12 “On-board control command and signaling” in the parameters list defined in Commission Regulation (EU) 2015/2299.

The relevant NRs for fixed installation including Control Command and Signaling trackside have to be notified to : NR4FI@era.europa

Feedback from ERTMS projects shows that ERTMS interoperability constituents and subsystems contain restrictions and specific conditions of use. The Control Command and Signalling (CCS) Technical Specification for Interoperability (TSI) requires that such information should be provided during the certification process.

Therefore, ERA has developed a template and related guidelines to ensure that the restrictions are described in a common and transparent way. The input for the template has to be provided by the applicant in collaboration with the Notified Body (NoBo).

A control command and signalling system does not brake, i.e. it is not responsible for the braking system of the train, which will do the actual job. ETCS (and also some elaborated legacy systems) supervises both the position and speed of the train to ensure they continuously remain within the allowed speed and distance limits, and -if necessary- it will command the intervention of the braking system to avoid any risk of the train exceeding those limits.

To do so, the ETCS onboard computer must predict the decrease of the train speed in the future, from a mathematical model of the train braking dynamics and of the track characteristics ahead. This prediction of the speed decrease versus distance is called a braking curve.

From this prediction, the ETCS onboard computer calculates in real time braking distances, which will also be used to assist the train driver and to allow him/her to drive comfortably, by maintaining the speed of the train within the appropriate limits.

The ETCS baseline 2 specifications lay down the basic principles for the braking curves and the associated information displayed to the driver, but there is still no harmonised method/algorithm to compute them.

The convergence towards a stable specification of the ETCS braking curve functionality has now been achieved and is reflected in the ETCS baseline 3 specifications.

The ETCS braking curves algorithm consists of a complex set of equations. The Agency has developed a tool, which allows predetermining all the braking distances, as they would be computed by the ETCS on-board equipment. The tool allows capturing all train data (including the correction factor K_dryrst obtained from the Monte Carlo calculation) and trackside, which are relevant to the braking curve calculation and displaying graphically the braking distances so calculated.

Even a successful certification process cannot always exclude that, when an on-board CCS subsystem interacts with a trackside CCS subsystem, one of the subsystems repeatedly fails to function or perform as intended under certain conditions. This may be due to variance in national control-command and signalling equipment (e.g. interlockings), engineering and operational rules, deficiencies in the specifications, different interpretations, design errors or equipment being installed incorrectly.

Therefore, checks might need to be carried out to demonstrate the technical compatibility of the control-command and signalling subsystems in the area of use for a vehicle. The necessity of these checks should be considered as a temporary measure to increase the confidence on the technical compatibility between the subsystems. The possibility of executing those checks in a laboratory representing the trackside configuration to be made available by the Infrastructure Manager should be prioritized.

ETCS System Compatibility

ETCS System Compatibility (ESC) shall be the recording of technical compatibility between ETCS onboard and the trackside ETCS part of the CCS subsystems within an area of use.

An “ESC type” is the value assigned to record the technical compatibility between an ETCS on-board subsystem and a section within an area of use. All sections of the Union network which require the same set of checks for the demonstration of ESC shall have the same ESC type.

Radio System Compatibility

Radio System Compatibility (RSC) shall be the recording of technical compatibility between voice or data radio on-board and the trackside GSM-R parts of the CCS subsystems.

An “RSC type” is the value assigned to record the technical compatibility between a voice or data radio part of the on-board subsystem and a section within an area of use. All sections of the Union network which require the same set of checks for the demonstration of RSC shall have the same RSC type.

More information about ESC/RSC definitions and the related procedures can be found in the CCS TSI Application Guide.

ESC/RSC Technical Document

The Agency shall set up and manage in a technical document the set of checks “ESC/RSC types” to demonstrate the technical compatibility of an on-board subsystem with the trackside subsystem. The link to the latest version of this document can be found below.

Infrastructure Managers, with the support of the ETCS and/or GSM-R suppliers for their networks, shall submit to the Agency the definition of the necessary checks (as defined in CCS TSI section 4.2.17) on their network by 16 January 2020 at the latest.

For submitting the ESC-RSC, please send it to us by e-mail.

The Agency will assign a unique identifier to each ESC/RSC type which will be communicated to the Infrastructure Manager. The corresponding identifiers will be also included in the predefined lists of values to be selected in RINF and ERATV.

The latest version of the files with the definition of the checks corresponding to each ESC and RSC types submitted by each Infrastructure Manager can be found in the following links:

Infrastructure Managers shall classify the lines according to ESC/RSC types in RINF, using the provided identifier.

ERATV users shall also include the ESC/RSC types that have been checked for the vehicles, using the identifiers in the technical document.

Infrastructure Managers shall submit to the Agency any changes on the referred checks for their networks, by using the same e-mail and making reference to the modified ESC/RSC type.

Agency report on the implementation of ETCS system compatibility (ESC) and radio system compatibility (RSC)

In accordance with Article 11a.1 of Commission Implementing Regulation (EU) 2019/776 of 16 May 2019 amending Commission Regulation (EU) 2016/919, the Agency has issued a report on the implementation of ETCS system compatibility (ESC) and radio system compatibility (RSC) checks, which can be found in the link below.

The report contains the analysis of the information received by the Agency up to the 25/05/2020, which is reflected in the ESC/RSC Technical Document version 4.0. The report also includes some proposed actions to be considered in the on-going revision of the Technical Specification for Interoperability relating to the Control-Command and Signalling subsystems envisaged for 2022.