Overview
ISO/TS 24315-3:2025, "Intelligent transport systems - Management of electronic traffic regulations (METR) - Part 3: System of systems requirements and architecture (SoSR)," defines end-to-end requirements and a reference architecture for a METR system of systems. The technical specification establishes how electronic traffic regulations (rules published in machine-readable form) are created, managed, distributed, verified and audited across ITS ecosystems. It introduces the system-level architecture used by subsequent METR parts and complements the operational concept given in ISO/TR 24315-2.
Key topics and technical requirements
This SoSR document addresses the full lifecycle and architecture of METR with emphasis on interoperability, information quality and system integrity. Key technical topics include:
- System-level requirements - End-to-end input/output, functional and information requirements for a METR SoS.
- Information flows - Defined flows for legal rules, coordination, discrepancy reporting, traffic control device (TCD) status, audit data and adaptation information.
- Functional capabilities - Rule verification, information storage and timeliness, filtering and processing expectations.
- ITS station unit requirements - Support services, timeliness constraints, filtering rules, open specification expectations, backward/forward compatibility and language neutrality.
- Information model needs - Feature catalogue, METR data elements, metadata, observable transport-rule attributes and auditing attributes.
- Architectural views - Functional, physical and enterprise views including centralized and localized distribution, discrepancy management, auditing, service discovery, credential/enrolment services, core authorization and system monitoring.
- Cybersecurity and conformance - Overview of security enrolment, credentials management and traceability/conformance conventions.
- Operational variables - Defined variables for intervals and response times (catalogueUpdateInterval, metrResponseTime, etc.) to support performance and reliability requirements.
Applications and who uses it
ISO/TS 24315-3 is intended for organizations involved in electronic traffic rules and ITS integration, including:
- Transport authorities and rule makers publishing machine-readable traffic regulations
- Traffic management centers and road operators implementing rule distribution and discrepancy handling
- ITS system architects, integrators and software developers building METR-compliant services
- Navigation and mapping providers, OEMs and telematics suppliers consuming METR data
- Auditors and compliance bodies verifying rule provenance, integrity and audit trails
Adoption of this SoSR supports interoperable, secure and traceable dissemination of electronic traffic regulations across mixed ITS ecosystems.
Related standards
Keywords: ISO/TS 24315-3, METR, intelligent transport systems, system of systems, electronic traffic regulations, reference architecture, traffic control devices, discrepancy management, ITS station requirements, cybersecurity.