The essential requirements can be summarised as safety, reliability and availability, health, environmental protection, technical compatibility and accessibility.

The formal definition of interoperability in the Interoperability Directive 2008/57/EC is ‘the ability of the rail system to allow the safe and uninterrupted movement of trains which accomplish the required levels of performance’.

TSIs are intended to foster the development of a single European railway system and therefore they apply to all mainline railways within the European Union.

You can find TSIs on the EUR-Lex website. RSSB maintains an up-to-date list of TSIs below.

The Department for Transport (DfT) is the body responsible for liaison with the European Commission about TSIs. Information about TSIs can be found on the DfT's Rail interoperability and standards page.

For further information please see the page on the Developing and amending TSIs.

How do TSIs relate to national technical rules?

National technical rules (NTRs) are used for the following purposes:

  • To fill identified 'open points' in TSIs
  • To support UK specific cases in TSIs
  • To support a derogation from a TSI
  • To set out requirements to maintain technical compatibility between existing assets (or processes) that do not conform to the requirements of TSIs and new, upgraded or renewed assets conforming to TSIs.

The Railway Interoperability Directive 2008/57/EC requires each Member State to notify to the European Commission the NTRs in use. Some Railway Group Standards are notified as NTRs for the purposes listed above.

Who must comply with TSIs?

The Railways (Interoperability) Regulations 2011 mandate compliance with TSIs on all mainline railways. These regulations transposed the Railway Interoperability Directive 2008/57/EC into domestic legislation and came into force on 16 January 2012.

The Railways (Interoperability) Regulations 2011 have been amended by the Railways (Interoperability) (Amendment) Regulations 2013, which came into force on 01 January 2014. For further information, see the Complying with Legislation page.

Following the scope extension, the TSIs apply to all mainline railways.  The scope of the mainline railway system where the TSIs apply can be found on the DfT website.

You must comply with a TSI if you are building new railway sub-systems or carrying out a major upgrade or renewal of an existing railway sub-system.  Replacement of parts of a sub-system on a like-for-like basis, for example replacing track with track of a similar specification, does not trigger a legal obligation to comply with TSIs.  The TSIs also contain requirements for interoperability constituents (ICs).

For further information on ICs and the national procedure to address the issue of ICs and specific cases, see the page on interoperability constituents.

Advice about whether a specific project must comply with TSIs can be obtained from the DfT.

The TSIs

In May 2019 TSIs were published in the Official Journal of the European Union and many of the updates reflect policy set out in the Fourth Railway Package Technical Pillar Commission Implementing Regulation (EU) 2019/776 (in force from 16 June 2019) amending the following TSIs.

  • CCS (EU) No 2016/919
  • ENE (EU) No 1301/2014
  • INF (EU) No 1299/2014
  • LOC&PAS (EU) No 1302/2014
  • SRT (EU) No 1303/2014
  • WAG (EU) No 321/2013

Control Command and Signalling TSI: Commission Regulation (EU) 2016/919

Note: From 1 January 2019, the set of specifications for the ETCS baseline 2 is not applicable any more for new vehicles to be placed on the market for the first time

RSSB contact: Alex Savopoulos, Principal Control, Command & Communications Engineer


Energy TSI: Commission Regulation (EU) 1301/2014

RSSB contact: Mike Tatton - Professional Head of Energy


Infrastructure TSI: Commission Regulation (EU) 1299/2014

RSSB contact: Jessal Murarji - Professional Head of Infrastructure


Locomotive & Passenger (LOC&PAS) TSI: Commission Regulation (EU) 1302/2014

The LOC&PAS TSI has been amended to close the open point regarding provisions on the energy measuring system and the data collecting system.  Commission Implementing Regulation (EU) 2018/868 amending Regulation (EU) No 1301/2014 and Regulation (EU) No 1302/2014 as regards provisions on energy measuring system and data collecting system.

RSSB contact: Mark Oakley - Professional Head of Rolling Stock


Noise (NOI) TSI: Commission Regulation (EU) 1304/2014

RSSB contact: Neil Halliday - Professional Head of Plant


Operation and Traffic Management (OPE) TSI: Commission Implementing Regulation (EU) 2019/773

The provisions on demonstrating route compatibility will only apply once a Member State has transposed the recast Interoperability Directive (2016/797). The UK has notified the European Commission that it intends to transpose the recast Interoperability Directive by 16 June 2020. See Article 6 for other applicable dates.

RSSB contact: Gary Portsmouth - Professional Head of Rail Operations


Rolling Stock (Freight Wagons) (WAG TSI): Commission Regulation (EU) 321/2013

RSSB contact: Neil Halliday - Professional Head of Plant


Telematics TSIs

Telematic Application for Freight (TAF TSI): Commission Regulation (EU) 1305/2014

RSSB contact: Gary Portsmouth - Professional Head of Rail Operations


Telematic Application for Passenger Services (TAP TSI): Commission Regulation (EU) 1273/2013 amending Regulation (EU) No 454/2011

RSSB contact: Gary Portsmouth - Professional Head of Rail Operations

Transverse TSIs (covering more than one railway sub-system)

Persons with Reduced Mobility (PRM TSI): Commission Regulation (EU) 1300/2014

RSSB contact: Jessal Murarji - Professional Head of Infrastructure and National Safety Authority representative


Safety in Railway Tunnels (SRT TSI): Commission Regulation (EU) 1303/2014

RSSB contact: John Lane - Principal Structures Engineer


TSI Conformity Assessment Modules

TSI conformity Assessment Modules: Decision 2010/713/EU

RSSB contact: Vaibhav Puri - Head of Technical & Regulatory Policy

Errors in TSIs

The DfT Rail interoperability TSI FAQ page describes how errors in TSIs are dealt with.

RSSB maintains a TSI application issues log (available in the resources section below) for recording information relating to problems that have been encountered when applying TSIs in GB. This is used to support discussions when TSIs are being amended.

The log is managed by RSSB but issues may be contributed by any railway organisation working with a TSI, including those on the GB mainline railway and HS1. Where appropriate, a document setting out further information relating to a particular issue should be included in the log via a hyperlink.

Any issue with a TSI should be raised with the appropriate industry sector representative on the standards committee for the relevant railway sub-system.

The Guide to the TSI application issues log (available in the resources section below) provides further information on how the log is to be managed and populated, including the role that the RSSB-facilitated Standards Committees may fulfil in providing a forum for industry discussion about suspected errors in TSIs and how to address them.

Please contact Vaibhav Puri on 020 3142 5446 if you require further information regarding TSIs.