What is BS EN 15531-1- Public transport about?
BS EN 15531-1 is a safety standard for public transport.
Real-time information may be exchanged between several different organizations, or between different systems belonging to the same organization. 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 diverse sources and several types of data suppliers and then distribute it onwards
- Between information provision systems and passenger information devices such as mobile phones, web browsers, etc.
Annex B of BS EN 15531-1 describes the business context for SIRI in more detail.
BS EN 15531-1 is intended for wide-scale, distributed deployment by a wide variety of installations. BS EN 15531-1 includes a formal versioning system that allows for the concurrent operation of various levels at the same time and a disciplined upgrade process.
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.
Who is BS EN 15531-1- Public transport for?
BS EN 15531-1 on service interface for real-time information relating to public transport operations is relevant to:
- General messaging service
- The standard interface for real-time information (SIRI)
- Public transport operations
- Data suppliers
- Network management
- Installers
Why should you use BS EN 15531-1- Public transport?
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 like:
- Setting schedules and timetables
- Managing vehicle fleets
- Issuing tickets and receipts
- Providing real-time
- Information on service running
BS EN 15531-1 specifies a Service Interface for Real-time Information (SIRI) about Public Transport. BS EN 15531-1 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 utilize real-time vehicle information, for example, to deliver services such as travel information. Using standardized 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 increasingly large and dynamic systems.
BS EN 15531-1 will improve several features of public transport information and service management:
Interoperability – BS EN 15531-1 will facilitate interoperability between information processing systems of the transport operators by:
- Introducing common architectures for message exchange
- Introducing a modular set of compatible information services for real-time vehicle information
- Using common data models and schemas for the messages exchanged for each service
- Introducing a consistent approach to data management
Improved operations management – BS EN 15531-1 will assist in better vehicle management by:
- Allowing the precise tracking of both local and roaming vehicles
- Providing data that can be used to improve performance, such as the measurement of schedule adherence
- Allowing the distribution of schedule updates and other messages in real-time
Delivery of real-time information to end-users – BS EN 15531-1 will assist the economic provision of improved data by:
- Enabling the gathering and exchange of real-time data between AVMS systems
- Providing standardized, 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 of BS EN 15531-1 include the following:
- Reusing a common communication layer for all the various technical services enables cost-effective implementations and makes BS EN 15531-1 readily extensible in future
Overall, BS EN 15531-1 is useful as it describes the communication layer that 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.

