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)-

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