Overview
ISO/TR 17739-1:2026 defines the general information, system architecture, and use cases related to roadside infrastructure supported location-based services for urban connected automated mobility on nomadic and mobile devices. This technical report is part of the ISO standards for intelligent transport systems (ITS). It focuses on improving road safety for all types of road users, including vulnerable road users (VRUs) such as pedestrians, bicyclists, and kickboard users, as well as users of vehicles equipped with automated or connected driving technologies.
The document outlines methods for sharing status or intent messages between nomadic device users and traditional ITS stations, leveraging roadside infrastructure equipped with AI-based detection. These mechanisms enable both safety enhancement and safety-critical services within localized urban areas such as intersections, roundabouts, school zones, and other traffic-sensitive environments.
Key Topics
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Nomadic Device-Supported Services: The standard clearly differentiates between road safety enhancing services (prevention, awareness, best practices) and safety-critical services (immediate warnings, collision avoidance).
- Enhancing services are intended to keep road users, especially VRUs and vehicle drivers using mobile devices, informed about potential risks.
- Critical services focus on timely warning alerts to prevent collisions, requiring low-latency communication.
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Actors and Communication:
- Actors include VRUs, drivers, passengers, vehicles (connected and non-connected), sensor-equipped roadside ITS stations, central ITS stations, and domain-specific application servers (e.g., infrastructure operators, service providers, vehicle OEMs).
- Communication involves localized (short-range, typically via vehicular WiFi or cellular V2X) and networked (long-range, typically 3G/4G/5G/6G mobile networks) channels, as well as hybrid models combining both.
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Communication Architecture:
- The document details information flows between nomadic devices, vehicle ITS stations, roadside ITS stations, and central ITS stations.
- It supports both direct (localized) and indirect (networked) communication for sending and receiving standardized ITS safety messages, facilitating interoperability and scalability across different service domains and geographic regions.
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Use Case Definition:
- A comprehensive set of use cases is provided, ranging from collision avoidance warnings and detection of unconnected VRUs to school bus passenger safety, and dynamic path obstacle reporting.
- Each use case outlines the service goal, actors, communication flows, required information, and post-conditions (e.g., collision avoidance, increased situational awareness).
Applications
- Urban Road Safety Enhancement: Supports real-time communication between all road users (including those not equipped with ITS devices) to prevent accidents, especially in complex urban environments.
- Vulnerable Road User Protection: Enables special consideration and protection for VRUs who are at greater risk in traffic situations, promoting equal safety for all road users.
- Connected and Automated Mobility Management: Facilitates integration of conventional and automated vehicles into a single ITS ecosystem, supporting advanced mobility applications.
- Localized Safety Management: Highly effective in specific urban areas like unsignalized intersections, roundabouts, school zones, and low-speed zones, targeting the most accident-prone spots with tailored safety solutions.
Related Standards
- SAE J2735 - Dedicated Short-Range Communications (DSRC) Message Set Dictionary for ITS applications.
- SAE J2945/x - Performance requirements for V2X communications.
- ETSI ITS EN 302 637 series - European standards for ITS communications, particularly for Cooperative Awareness Messaging (CAM) and Decentralized Environmental Notification Messaging (DENM).
- ISO 21217 - Architecture and terminology for ITS station reference architecture.
- ETSI ITS TS 103 300 series - Further message and protocol standardization for ITS.
Conclusion
ISO/TR 17739-1:2026 provides foundational guidance for implementing roadside infrastructure supported location-based services using nomadic devices in urban ITS environments. By enabling real-time, standardized message exchange and defining clear use cases, the standard promotes universal road safety improvements and paves the way for more connected, automated, and inclusive urban mobility solutions. Organizations seeking to deploy intelligent transport systems in cities will find practical value in this standard’s approach to integrating mobile devices, AI-enabled roadside sensors, and centralized ITS management.