SIRI — Service Interface for Real Time Information (EN 15531 / CEN/TS 15531 series)

Scope

SIRI (Service Interface for Real Time Information, EN 15531 / CEN/TS 15531) is the European standard for exchanging real-time public transport information — vehicle positions, predicted arrivals, service disruptions and situation messages — between operator, authority and passenger-information systems. Established as a CEN standard since October 2006, it is Transmodel's real-time implementation, complementing NeTEx's static schedule and fare data.

SIRI is organised in seven parts: Part 1 context and framework (EN 15531-1:2015), Part 2 communications (EN 15531-2:2015) and Part 3 functional service interfaces (EN 15531-3:2015) form the normative European Standard core, while Parts 4-7 are CEN Technical Specifications covering facility monitoring (CEN/TS 15531-4:2011), situation exchange (CEN/TS 15531-5:2016), control actions (CEN/TS 15531-6:2024) and, newest, the European Real Time Passenger Information Profile (CEN/TS 15531-7:2024, under approval at time of writing). SIRI enables server-to-server exchange of schedules, vehicle positions and connection information, feeding stop and vehicle displays, journey-planning apps and inter-operator roaming for services crossing operational boundaries. SIRI and NeTEx share the same Transmodel conceptual model and are typically implemented as a pair — NeTEx publishing what should happen, SIRI reporting what is actually happening — by public transport authorities, infrastructure managers and mobility-data platforms across Europe. It is a voluntary CEN standard, not OJ-cited under the Interoperability Directive; national SIRI profiles adapting the generic specification to local systems are documented on the Data4PT wiki and by the transmodel-cen.eu community, which is also the reference source used for this library entry.