Overview
ISO/TR 14823-2:2019 is a Technical Report from ISO/TC 204 that provides concrete examples of ASN.1 encoding for a Graphic Data Dictionary (GDD) used in Intelligent Transport Systems (ITS). The document illustrates how to represent road traffic pictograms and sign attributes in a language‑independent, IT‑centric way so encoded sign data can be transmitted, interpreted and displayed in ITS applications (for example, in‑vehicle signage).
Key topics and technical requirements
- ASN.1 schema for GDD: The report documents the GDD structure consisting of pictogramCode and optional GddAttributes, showing how pictograms are encoded with ASN.1 types and tags.
- Pictogram identification: A pictogramCode contains a countryCode (ISO 3166‑1), serviceCategoryCode (e.g., traffic sign, public facility, road conditions) and pictogramCategoryCode (nature and serial number). The service/category encoding is aligned with ISO 14823‑1.
- Attribute set examples: The report gives ASN.1 examples for attributes that qualify pictograms, including:
- applicablePeriod / exemptedApplicablePeriod (time/date validity)
- directionalFlowOfLane and numberOfLane (lane/direction semantics)
- applicableVehicleDimensions (height, width, length, weight)
- speedLimits (max/min and unit)
- rateOfIncline, distanceBetweenVehicles
- distinationInformation (destination, junction, roundabout, distances)
- section (start/continuity lengths)
- Units and value ranges: Attributes reference unit codes (Code‑Units) and numeric ranges (e.g., Year, HoursMinutes, Distance, Weight) consistent with the ASN.1 schema shown in the report.
- Interoperability notes: Some ASN.1 codes in the examples are re‑formatted based on ISO 14813‑6; the report is intended to be used jointly with ISO 14823‑1 (normative) for full specification.
Applications and users
- Who uses it: ITS system integrators, automotive OEMs, map vendors, traffic control agencies, and developers of in‑vehicle information systems and VMS (Variable Message Signs).
- Practical applications:
- Encoding and transmitting sign/pictogram data in road telematics and vehicle communications.
- Consistent decoding and rendering of signs across regions, supporting multi‑country deployments and language‑independence.
- Translating sign representations between national conventions for international traffic services.
Related standards
- ISO 14823‑1 - Graphic data dictionary (normative specification for the GDD and coding rules).
- ISO 14813‑6 - Formatting influence referenced for some ASN.1 re‑formatting.
- ISO/TS 17425 - In‑vehicle signage use case referenced by the report.
Keywords: ISO/TR 14823-2:2019, Intelligent Transport Systems, Graphic Data Dictionary, GDD, ASN.1, pictogram, in‑vehicle signage, traffic sign encoding, ITS messaging, international traffic standards.