Standard Interface for Real-time Information

SIRI is a CEN Technical Standard that specifies a European interface standard for exchanging information about the planned, current or projected performance of real-time public transport operations between different computer systems.

SIRI It is divided into five parts, each compliant with CEN Transmodel:

  • Part 1: Context and framework (CEN/TS 15531-1:2015);
  • Part 2: Communications infrastructure (CEN/TS 15531-2:2015);
  • Part 3: Functional service interfaces (CEN TS/15531-3:2015);
  • Part 4: Functional service interfaces: Facility Monitoring (CEN/TS 15531-4:2011);
  • Part 5: Functional service interfaces – Situation Exchange (CEN/TS 15531-05:2016)-

As regards the SIRI-SX and SIRI-FM,  these parts are of specific relevance for Transmodel (Part 4: Operations Monitoring and Control).

  • The SIRI Situation Exchange service (EN 15531-5) covers the exchange of information describing an incident, typically an unplanned event such as a disruption, but also planned events that affect public transport or its use, such as engineering works, or major public events that will affect the use or availability of transport. The SIRI-SX service was originally designed to be, as far as possible, consistent with the DATEX II and TPEG standards, which also include situation and public event representations.
  • The SIRI Facility Monitoring service (EN 15531-4) covers the exchange of information concerning the current status of facilities (corresponding to kind of Transmodel EQUIPMENT). It provides a short description of the facility itself, the availability status and specifically the impact of the availability status for various categories of disabled or incapacitated people.

Both Situation Exchange and Facility Monitoring services encompassed extensions to the Transmodel 5.0 conceptual model on which they are based. Transmodel 6.0 has taken these extensions as input change requests, and the reference model has been updated accordingly to support them.

SIRI allows pairs of server computers to exchange structured real-time information about schedules, vehicles, and connections, together with general informational messages related to the operation of the services. The information can be used for many different purposes, for example:

  • To provide real time-departure from stop information for display on stops, internet and mobile delivery systems;
  • To provide real-time progress information about individual vehicles;
  • To manage the movement of buses roaming between areas covered by different servers;
  • To manage the synchronisation of guaranteed connections between fetcher and feeder services;
  • To exchange planned and real-time timetable updates;
  • To distribute status messages about the operation of the services;
  • To provide performance information to operational history and other management systems.

Transmodel has been a fundamental input; more information can be found at