prEN 15531-1

Public transport - Service interface for real-time information relating to public transport operations - Part 1: Context and framework

Service Interface for Real Time Information (SIRI) is a specification for an interface that allows systems running computer applications to exchange information about the planned, current or projected performance of the public transport operations.
The scope of this WI is to update CEN/EN 15531-1:2015 which 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.
Implementations SIRI have revealed a number of improvements and some minor enhancements necessary for a successful and uniform usage of the specification in the future.
The main elements out of this work item will be:
o Prepare an updated edition of the TS as a document
o Update the common XSD of SIRI parts 1-5
The new work item will consider the projects of
o PT companies and IT-suppliers especially in Switzerland, Germany, France, Netherlands and Sweden
o Railway traffic
o accessibility in public transport

Öffentlicher Verkehr - Serviceschnittstelle für Echtzeitinformationen bezogen auf Operationen im öffentlichen Verkehr - Teil 1: Kontext und Grundstruktur

Transport public - Interface de service pour les informations en temps réel relatives aux opérations de transport public - Partie 1 : Cadre et contexte

1.1 Interfaces spécifiées par la présente norme
1.1.1 Contexte économique
Les informations en temps réel peuvent être échangées entre différentes organisations ou entre différents systèmes appartenant à la même organisation. Les interfaces clés incluent ce qui suit :
• Entre les centres de contrôle des véhicules de transport public – généralement pour la gestion de parcs et de réseaux.
• Entre un centre de contrôle et un système de diffusion d'informations – généralement pour fournir des informations opérationnelles destinées à être mises à la disposition du public.
• Entre les systèmes de diffusion d'informations – généralement pour partager des informations afin de garantir que les informations accessibles au public sont complètes et détaillées.
• Entre les systèmes de diffusion d'informations et les systèmes d'agrégation de données qui collectent et intègrent les données provenant de différentes sources et de différents types de fournisseurs de données, puis les distribuent ensuite.
• Entre les systèmes de diffusion d'informations et les appareils d'information voyageur tels que les téléphones mobiles, les navigateurs Web, etc.
L'Annexe B décrit le contexte économique de la norme SIRI d'une manière plus approfondie.
La norme SIRI est destinée au déploiement réparti à grande échelle pour de nombreuses installations. Dans de telles circonstances, la mise à niveau de tous les systèmes en même temps est souvent irréalisable. C'est pourquoi la SIRI inclut un système formel de contrôle des versions qui permet le fonctionnement simultané de différents niveaux en même temps ainsi qu'un processus de mise à niveau discipliné.
Dans ce cadre général, la norme SIRI définit un ensemble spécifique de services fonctionnels concrets. Les services séparent les protocoles de communication du contenu du message (« services fonctionnels »). Cela permet au même contenu fonctionnel d'être échangé par le biais de différents mécanismes de transport et schémas d'échange. La Figure 1 ci-dessous en est une illustration schématique.
1.1.2 Communication SIRI
La norme SIRI fournit un ensemble cohérent de services fonctionnels concernant l'échange de données pour différents aspects de fonctionnement PT. Tous les services utilisent un modèle de données commun, basé sur Transmodel 6.0.
[Figure 1]
[...]
1.1.3 Services fonctionnels SIRI
[...]
1.2 Utilisation de la norme SIRI
[...]
1.3 Limitations concernant la norme SIRI et les développements futurs possibles
[...]

Javni prevoz - Vmesnik za informiranje v realnem času za potrebe delovanja javnega prevoza - 1. del: Skladnost in okvir

General Information

• Status: Not Published
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: CEN/TC 278 - Road transport and traffic telematics
• Drafting Committee: CEN/TC 278/WG 3 - Public transport (PT)
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Due Date: 02-Dec-2021
• Completion Date: 02-Dec-2021
• Ref Project: oSIST prEN 15531-1:2021 - Public transport - Service interface for real-time information relating to public transport operations - Part 1: Context and framework

RELATIONS

• Revised: EN 15531-1:2015 - Public transport - Service interface for real-time information relating to public transport operations - Part 1: Context and framework
• Effective Date: 08-Apr-2020

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 15531-1:2021
01-september-2021
Javni prevoz - Vmesnik za informiranje v realnem času za potrebe delovanja
javnega prevoza - 1. del: Skladnost in okvir

Public transport - Service interface for real-time information relating to public transport

operations - Part 1: Context and framework

Öffentlicher Verkehr - Serviceschnittstelle für Echtzeitinformationen bezogen auf

Operationen im öffentlichen Verkehr - Teil 1: Kontext und Grundstruktur

Transport public - Interface de service pour les informations en temps réel relatives aux

opérations de transport public - Partie 1 : Cadre et contexte
Ta slovenski standard je istoveten z: prEN 15531-1
ICS:
35.240.60 Uporabniške rešitve IT v IT applications in transport
prometu
oSIST prEN 15531-1:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 15531-1:2021
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oSIST prEN 15531-1:2021
DRAFT
EUROPEAN STANDARD
prEN 15531-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2021
ICS 35.240.60 Will supersede EN 15531-1:2015
English Version
Public transport - Service interface for real-time
information relating to public transport operations - Part
1: Context and framework

Transport public - Interface de service pour les Öffentlicher Verkehr - Serviceschnittstelle für

informations en temps réel relatives aux opérations de Echtzeitinformationen bezogen auf Operationen im

transport public - Partie 1 : Cadre et contexte öffentlichen Verkehr - Teil 1: Kontext und

Grundstruktur

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 278.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15531-1:2021 E

worldwide for CEN national Members.
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Contents Page

1 Scope .................................................................................................................................................................... 7

1.1 Interfaces specified by this Standard ....................................................................................................... 7

1.2 Use of the SIRI standard ................................................................................................................................ 9

1.3 Limitations on SIRI and Possible Future Developments ................................................................ 10

2 Normative references ................................................................................................................................. 11

3 Terms and definitions ................................................................................................................................ 11

3.1 Transport Related Terms .......................................................................................................................... 11

3.2 Communications and Software Concepts ............................................................................................ 34

4 Symbols and abbreviations ...................................................................................................................... 46

5 Types of Reference Data Used in SIRI ................................................................................................... 47

5.1 General ............................................................................................................................................................. 47

5.2 Date and time format .................................................................................................................................. 48

5.3 Location coordinate system ..................................................................................................................... 49

5.4 National language of text elements ....................................................................................................... 50

5.5 Participant (information provider) identification........................................................................... 50

5.6 Participant pair identification (service participant pair code) ................................................... 51

5.7 Point and place references ....................................................................................................................... 51

5.8 Vehicle journey references ....................................................................................................................... 53

5.9 Line, and direction references ................................................................................................................. 54

5.10 Stop sequence references and circular journeys .............................................................................. 55

5.11 Schedule version references .................................................................................................................... 57

5.12 Product category references .................................................................................................................... 57

5.13 Vehicle feature references ........................................................................................................................ 58

5.14 Service features ............................................................................................................................................ 58

5.15 Situation references .................................................................................................................................... 60

5.16 Summary of Data Reference Scopes ...................................................................................................... 61

5.17 Transmodel Compliant Models ............................................................................................................... 62

5.18 Modelling Vehicle Journeys in SIRI ........................................................................................................ 62

6 Notation ........................................................................................................................................................... 70

6.1 Representation of XML model elements in Text ............................................................................... 70

6.2 Representing Relationships in SIRI ....................................................................................................... 70

6.3 Notation for XML model structures of SIRI messages ..................................................................... 71

6.4 Notation for Diagrams ................................................................................................................................ 73

Annex A (informative) Checklist for Implementing SIRI ............................................................................ 74

A.1 Usage of the DSRC application layer ...................................................................................................... 74

A.2 Legal and Commercial Issues ................................................................................................................... 74

A.3 Functional Aspects ....................................................................................................................................... 74

A.4 Operational Aspects .................................................................................................................................... 77

Annex B (informative) Business Context .......................................................................................................... 78

B.1 Purpose of This Section .............................................................................................................................. 78

B.2 Business Model ............................................................................................................................................. 79

B.3 Use of information in Public Transport ............................................................................................... 82

B.4 Use Cases for this Standard ...................................................................................................................... 87

B.5 SIRI System Model ........................................................................................................................................ 92

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Annex C (informative) Background and Mapping of Some Current Implementations to SIRI....... 97

C.1 Introduction.................................................................................................................................................... 97

C.2 SIRI origins ...................................................................................................................................................... 97

C.3 Deployment Example – Berlin ............................................................................................................... 100

C.4 Deployment Example – Hamburg ........................................................................................................ 101

C.5 Deployment Example – West Yorkshire ............................................................................................ 102

C.6 Deployment Example – Czech Republic ............................................................................................. 103

C.7 Deployment Example – Copenhagen .................................................................................................. 104

C.8 Deployment example – Île-de-France ................................................................................................. 106

C.9 SIRI Equivalences ....................................................................................................................................... 107

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European foreword

This document (prEN 15531-1:2021) has been prepared by Technical Committee CEN/TC 278

“Intelligent transport systems”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 15531-1:2015.

SIRI (CEN/TS 15531-1:2006) has been a CEN Technical Specification since 2007 and a European

normative standard since 2013 and has been widely used in Europe and elsewhere and proven its

usefulness. This document proposes a revised version of SIRI as a European Standard, and is currently

submitted to the Formal Vote. The proposed revisions are minor enhancements arising from experience

of the deployment of SIRI in many live systems. This document also clarifies the relationship of SIRI to

NeTEx, the CEN Technical Standard for the XML exchange of Public Transport Reference data based on

the Transmodel CEN European Standard.

This document presents Part 1 of the European Standard known as “SIRI”. SIRI provides a framework

for specifying communications and data exchange protocols for organisations wishing to exchange Real-

time Information (RTI) relating to public transport operations.
The SIRI European Standard is presented in three parts:

• context and framework, including background, scope and role, normative references, terms and

definitions, symbols and abbreviations, business context and use cases (Part 1),
• the mechanisms to be adopted for data exchange communications links (Part 2),

• data structures for a series of individual application interface modules PT, ET, ST, SM, VM, CT, CM,

GM (Part 3).

Two additional parts define additional functional services as CEN Technical Specifications:

• additional data structures for additional application interface module FM (Part 4),

• additional data structures for additional application interface module SX (Part 5).

The XML schema can be downloaded from https://github.com/SIRI-CEN/SIRI, guidance on its use,

example XML files, and case studies of national and local deployments is located at http://siri-cen.eu/.

It is recognised that SIRI is not complete as it stands, and from time to time will need to continue to be

enhanced to add additional capabilities. It is therefore intended that a SIRI Management Group should

continue to exist, at European level, based on the composition of SG7.
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Introduction

Public transport services rely increasingly on information systems to ensure reliable, efficient operation

and widely accessible, accurate passenger information. These systems are used for a range of specific

purposes: setting schedules and timetables; managing vehicle fleets; issuing tickets and receipts;

providing real-time information on service running, and so on.

This European Standard specifies a Service Interface for Real-time Information (SIRI) about Public

Transport. It is intended to be used to exchange information between servers containing real-time

public transport vehicle or journey time data. These include the control centres of transport operators

and information systems that utilise real-time vehicle information, for example, to deliver services such

as travel information.

Well-defined, open interfaces have a crucial role in improving the economic and technical viability of

Public Transport Information Systems of all kinds. Using standardised interfaces, systems can be

implemented as discrete pluggable modules that can be chosen from a wide variety of suppliers in a

competitive market, rather than as monolithic proprietary systems from a single supplier. Interfaces

also allow the systematic automated testing of each functional module, vital for managing the

complexity of increasing large and dynamic systems. Furthermore, individual functional modules can be

replaced or evolved, without unexpected breakages of obscurely dependent function.

This European Standard will improve a number of features of public transport information and service

management:

• Interoperability – the European Standard will facilitate interoperability between information

processing systems of the transport operators by: (i) introducing common architectures for

message exchange; (ii) introducing a modular set of compatible information services for real-time

vehicle information; (iii) using common data models and schemas for the messages exchanged for

each service; and (iv) introducing a consistent approach to data management.

• Improved operations management – the European Standard will assist in better vehicle

management by (i) allowing the precise tracking of both local and roaming vehicles; (ii) providing

data that can be used to improve performance, such as the measurement of schedule adherence;

and (iii) allowing the distribution of schedule updates and other messages in real-time.

• Delivery of real-time information to end-users – the European Standard will assist the economic

provision of improved data by; (i) enabling the gathering and exchange of real-time data between

AVMS systems; (ii) providing standardised, well defined interfaces that can be used to deliver data

to a wide variety of distribution channels. Version 2.0 of SIRI includes a new Simple Web Service

designed to support the widespread, massively scalable use of mobile devices and web browsers

and other applications to display public transport data directly to users.
Technical advantages include the following:

• Reusing a common communication layer for all the various technical services enables cost-effective

implementations and makes the European Standard readily extensible in future.
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History

Version 1.0 of SIRI was developed in 2004-2005 and submitted to vote, eventually passing through the

CEN process to become an approved CEN Technical Specification in 2007. As well as the normative

Version 1.0 XSD schema, successive informal working versions of the schema (v 1.1 – 1.4) were released

to allow for fixes and to implement some very minor enhancements agreed by the working group. A

WSDL version was also developed.

Version 2.0 of SIRI was developed in 2012 to coincide with making the SIRI standard a full CEN norm.

SIRI includes a Simple Web Services “SIRI-LITE” as an additional transport method and a WSDL

document literal version and a WSDL2 version;

Version 2.1 of SIRI was developed in 2020/21 to address lessons from the now widespread

implementation of SIRI.
The changes in SIRI version 2.1 include:

• remove the direct relationship with TPEG and other standards to enable support as the other

standards change;
• support for new modes in line with TRANSMODEL and NeTEx;
• support for the Reason / Effect / Advice structure for disruptions in SIRI SX;
• increased granularity for occupancy data and Vehicle structures;
• improved subscription renewal options and filtering options;

• additional options and flexibility for STOP POINTS and relationships between journeys;

• migration of XSD to Github to improve access and change control processes.
Compatibility with previous versions

All changes in version 2.1 are intended to be fully backwards compatible, that is to say, existing

documents that validate against earlier versions of the schema will also validate against the 2.1 schema

without alteration (other than to schema version numbers), and version 2.1 documents that do not use

new features will validate against earlier versions. Version 2.1 documents that use new features will not

be backwards compatible.
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1 Scope
1.1 Interfaces specified by this Standard
1.1.1 Business Context

Real-time information may be exchanged between a number of different organisations, or between

different systems belonging to the same organisation. Key interfaces include the following:

• Between public transport vehicle control centres – generally, for fleet and network management.

• Between a control centre and an information provision system – generally, to provide operational

information for presentation to the public.

• Between information provision systems – generally, sharing information to ensure that publicly

available information is complete and comprehensive.

• Between information provision systems – and data aggregation systems that collect and integrate

data from many different sources and different types of data supplier and then distribute it

onwards.

• Between information provision systems and passenger information devices such as mobile phones,

web browsers, etc.
Annex B describes the business context for SIRI in more detail.

SIRI is intended for wide scale, distributed deployment by a wide variety of installations. In such

circumstances it is often not practical to upgrade all the systems at the same time. SIRI therefore

includes a formal versioning system that allows for the concurrent operation of different levels at the

same time and a disciplined upgrade process.

In this general framework, SIRI defines a specific set of concrete functional services. The services

separate the communication protocols from the message content (‘functional services’). This allows the

same functional content to be exchanged using different transport mechanisms, and different patterns

of exchange. Figure 1 below shows this diagrammatically.
1.1.2 SIRI Communications

SIRI provides a coherent set of functional services for exchanging data for different aspects of PT

operation. A common data model, based on Transmodel 6.0, is used across all services.

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Figure 1 — Structure of SIRI: a set of optional service interface specifications using a common

communication layer

A communication layer defines common procedures for the requesting and exchanging of data. Within

SIRI, the same general communication protocols are used for all the different concrete functional

interfaces, and specify a common infrastructure for message referencing, error handling, reset

behaviour and so forth. The communications layer is defined in Part 2 of the SIRI document set.

To allow the most efficient use to be made of bandwidth and processing capacity, the SIRI

communications architecture supports several different patterns of interaction. SIRI supports both

request/response and publish/subscribe protocols between servers, allowing applications both to pull

or to push data.

The SIRI publish/subscribe pattern of interaction follows the paradigm described in the W3C candidate

standard ‘Publish-Subscribe Notification for Web Services (WS-PubSub)’. SIRI uses the same separation

of concerns, and a similar terminology for Publish/Subscribe concepts as is used in WS-PubSub.

For the delivery of data in response to both requests and subscriptions, SIRI supports two common

patterns of message exchange as realised in existent national systems:
• one-step ‘direct’ delivery: allowing the simple rapid delivery of data;

• two-step ‘fetched’ delivery: allowing a more optimised use of limited resources.

1.1.3 SIRI Functional Services

SIRI provides specific protocols for the following functional services, defined in Part 3 of the SIRI

document set:

• Production Timetable (PT) Service: to send daily information on the operational timetable and

associated vehicle running information.
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• Estimated Timetable (ET) Service: to send real-time information on timetable, including changes

based on the production service and on actual running conditions.

• Stop Timetable (ST) Service: to provide a stop-centric view of timetabled vehicle arrivals and

departures at a designated stop.

• Stop Monitoring (SM) Service: to send real-time arrival & departure information relating to a

specific stop.

• Vehicle Monitoring (VM) Service: to send real-time information on the movement and predicted

movement of vehicles.

• Connection Timetable (CT) Service: to send an operational timetable for a service feeding an

interchange, in order to inform departing services of the possible need to wait for connecting

passengers.

• Connection Monitoring (CM) Service: to send real-time information on the running of a service

inbound to an interchange, in order to advise departing services of the need to wait for connecting

passengers. This can also be used to send real-time information to assist passengers in planning

their onward journey following a connection.

• General Message (GM) Service: to exchange informative messages between participants.

Two additional functional services, are provided as additional parts:

• Facilities Management (FM) Service: to exchange information on the current status of facilities

such as lifts, escalators or ticketing machines (Part 4).

• Situation Exchange (SX) Service: to exchange information messages between identified

participants in a standardised structured format suitable for travel information services (Part 5).

1.2 Use of the SIRI standard

As a framework standard, it is not necessary for individual systems or specifications to implement the

whole of the SIRI standard. Specifically, it is intended that individual national bodies may adopt

consistent subsets of the standard. However, it should be possible to describe (for those elements of

systems, interfaces and specifications which fall within the scope of SIRI):
• the aspects of SIRI that they have adopted;
• the aspects of SIRI that they have chosen not to adopt.

In other words, there is no global statement of which elements are mandatory and which optional

(except for key fields which are clearly always mandatory).

SIRI is a modular and expandable standard, and the modules included in this version are only a subset

of what might potentially be included. Specifically, the current issue of the SIRI specification excludes

the following:
• interfaces with traffic management systems for traffic light priority;
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• control action functions, e.g. instructions to a vehicle to change its running;

• functionality of actual systems – SIRI only specifies the interfaces between servers, not how they

choose to implement it.

Since its inception SIRI has been enhanced and extended to meet additional requirements. The potential

for SIRI to be expended to encompass additional services will continue to be reviewed in future.

Guidance on the implementation and use of SIRI is not part of the specification. It is a matter for

individual users and national groupings to provide advice and guidance on how SIRI may be used in

support of local practices.

Note also that the SIRI communications layer does not specify the communication bearer technologies

to be used. SIRI has been specifically developed to be ‘technology independent’ in this regard, so that

local implementations can select the most cost-effective services for their projects.

Of course different technologies have different characteristics, and this may have an impact on the way

that SIRI is used in practice. For example, the latency (time delay imposed by the communications

network) of a service such as public GPRS is much higher than that on a dedicated, broadband fixed link

using DSL. Therefore, systems based on GPRS will need to use a much higher value for some or all of the

hysteresis parameters.
1.3 Limitations on SIRI and Possible Future Developments

The developers of this standard recognise that there is continual development in the business practice

of the public transport industry, and that SIRI must continue to evolve to fulfil its needs. Specifically,

there is scope for additional elements to be included in two places:

• Communications (SIRI Part 2). New mechanisms of data communication are constantly becoming

available, in particular for areas such as information security and data discovery. SIRI is intended to

be in line with prevailing information systems industry practice and Part 2 aims to retain flexibility

in use of communications technologies. SIRI 2.0 introduces addition transports in form of the

Document Literal WSDL and a RESTful presentation of services.

• Applications (SIRI Part 3, Part 4, Part 5, etc). This standard is based on a specific set of interfaces,

representing a subset of practical needs among participant countries. However, new models of

business cooperation may arise which necessitate additional application interface specifications.

The current functional services are not intended to be a complete set of interfaces and additional

modules might be required in future.

• Architectural detail. This standard is based on a very high-level decomposition of public transport

operations, and implements only the most common interfaces. This may not fulfil all the needs of an

implementer; for example, Scandinavia and the UK both have a relatively high degree of

organisational disaggregation, and as a result may need standardisation on what would be ‘internal’

interfaces elsewhere in Europe.

CEN welcomes input from users of this Standard as to where SIRI needs extension or refinement.

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2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 8601, Data elements and interchange formats – Information inter
...