Overview
CEN ISO/TR 6026:2022 (ISO/TR 6026:2022) is a technical report and pre-study on using vehicle licence plate number (LPN) information and automatic number plate recognition (ANPR) technologies in electronic fee collection (EFC) systems. Prepared by ISO/TC 204 and CEN/TC 278, the document analyses legal, technical and functional contexts for LPN‑based EFC, provides a standards gap analysis (based on the European Electronic Toll Service - EETS model), and proposes a roadmap to address identified gaps. Annex A offers real-world examples of LPN-based tolling schemes.
Key topics and technical requirements
- Legal context and licence plate characteristics: regulated licence plates, physical plate features and country variations that affect recognition reliability and data handling.
- ANPR recognition process and limitations: image acquisition, preprocessing, optical character recognition (OCR), error margins, accuracy challenges and factors that degrade performance (weather, speed, plate variants).
- LPN data handling and validation: procedures for validating LPN reads, handling illegal or spoofed plates, and integrating with vehicle registers.
- Use cases and business processes: registration, recognition, charging, enforcement and exception handling for LPN-based tolling.
- Technical interfaces (TI 1–TI 7): definition of interfaces such as toll context definition, user registration, user list exchange, recognition interface, billing, user data retrieval and enforcement.
- Gap analysis findings: missing specifications and tests for back-office (BO) interfaces, undefined performance metrics, incomplete content definitions for LPN-based information, security requirements, image acquisition performance standards, and interfaces to vehicle registries.
- Standards alignment: recommendations to align with EFC architecture, vocabulary and data dictionaries (referencing the ISO 17573 series) and a proposed standardization roadmap.
Applications and who uses it
CEN ISO/TR 6026 is relevant to:
- Toll and congestion-charge operators
- Transport authorities and policy makers
- ITS system integrators and ANPR vendors
- Parking management and enforcement agencies
- Standards developers and testing bodies
The report supports design, procurement and interoperability of LPN‑based EFC systems - from roadside ANPR camera deployment to back-office billing and cross-border EETS implementations.
Related standards and next steps
- ISO/TR 6026 complements work from ISO 17573 (EFC architecture/data dictionary) and is intended to guide further standardization activities under CEN/TC 278 and ISO/TC 204.
- The roadmap in the report prioritizes developing BO interface specs, testing regimes, performance metrics and security requirements to enable standardized, interoperable LPN/ANPR-based fee collection.
Keywords: ANPR, LPN, electronic fee collection, EFC, ISO/TR 6026, CEN, EETS, licence plate recognition, ITS, tolling standards, gap analysis.