kSIST-TS FprCEN ISO/TS 25588:2026

• Abstract:

  Specification of the set-up of a testing system and the test suite structure and test purposes, i.e. tests to be used to assess conformity to specification of the processes that implement an image-based tolling system.

• Status: Not Published
• Public Enquiry End Date: 29-Sep-2026
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ITC - Information technology
• Current Stage: 5520 - Unique Acceptance Procedure (UAP) (Adopted Project)
• Start Date: 22-Jul-2026
• Due Date: 09-Dec-2026
• Completion Date: 20-Aug-2026
• Directive: Not Harmonized2019/520 - Directive (EU) 2019/520 of the European Parliament and of the Council of 19 March 2019 on the interoperability of electronic road toll systems and facilitating cross-border exchange of information on the failure to pay road fees in the Union (Text with EEA relevance.)
• Ref Project: FprCEN ISO/TS 25588 - Electronic fee collection - Image-based systems - Test suite structure and test purposes (ISO/DTS 25588:2026)

Overview

kSIST-TS FprCEN ISO/TS 25588:2026 is a technical specification developed by the Slovenski inštitut za standardizacijo (SIST) and aligned with ISO and CEN standards, addressing electronic fee collection (EFC) via image-based systems. This standard defines the setup, structure, and purposes of a comprehensive test suite to assess the conformity of image-based tolling systems. It describes how to systematically test and validate the key processes of EFC systems that rely on image analysis, such as vehicle detection, identification, and classification, ensuring reliable toll collection and system interoperability.

By providing clear requirements for laboratory and on-site testing, as well as specifying the necessary interfaces and event formats, the standard fosters the development, deployment, and verification of robust image-based EFC solutions.

Key Topics

• Testing System Setup: Outlines requirements for both laboratory and on-site test environments, specifying lighting, motion simulation, vehicle classes, environmental conditions, and sensor types.
• Test Suite Structure: Describes a logical approach for organizing tests, including laboratory and field tests for passage detection, vehicle identification, and classification.
• Test Purposes: Establishes clear test objectives for each system component, focusing on isolated process behavior within EFC systems.
• Interface Specifications: Defines necessary interfaces and data exchange formats among system components, ensuring traceability, time-stamping, and real-time event capture.
• Conformity Assessment: Emphasizes evaluating system behavior against defined processes and variables to validate that EFC solutions meet performance and reliability expectations.
• Event Generation & Logging: Stipulates how events (such as detections or identifications) must be logged, time-stamped, and reviewed for missed detections or misclassifications.

Applications

The kSIST-TS FprCEN ISO/TS 25588:2026 standard is crucial for stakeholders involved in designing, implementing, and testing image-based electronic toll collection systems. Its applications include:

• Toll Operators and Solution Providers: Ensures that deployed EFC systems can be rigorously tested for compliance, optimizing performance and reducing fraud.
• System Integrators: Provides a guideline for integrating components like ANPR cameras, sensors, and central systems within a standard-compliant architecture.
• Testing Laboratories and Certification Bodies: Offers methodologies for designing, conducting, and reporting conformity tests for EFC systems.
• Procurement and Regulators: Assists authorities in specifying requirements and verifying solutions before large-scale deployments or public tenders.

Use cases extend beyond traditional tolling, as the standard’s principles can be applied to related fields such as:

• Parking Management: Automated vehicle entry/exit tracking and compliance verification.
• Traffic Violation Detection: Evidence generation for enforcement procedures.
• Vehicle Compliance and Roadside Inspection: Supporting non-stop compliance checks and automated road-use charging.
• Smart City ITS Applications: Data collection and analysis for urban mobility management, leveraging accurate image-based vehicle recognition.

Related Standards

• ISO 17573-2 - Electronic fee collection - System architecture for vehicle related tolling - Vocabulary: Establishes key terminology and architectural principles referenced in this technical specification.
• ISO/TR 25221 - Image-based systems for electronic fee collection: Details fundamental processes and variables relevant to EFC, forming the foundation for testing methods.
• ISO/TS 37444 (forthcoming) - Electronic fee collection - Key performance indicators: Expected to specify performance thresholds and KPIs for EFC systems, complementing this standard’s conformity focus.
• CEN/TC 278 Standards - A family of technical specifications for Intelligent Transport Systems (ITS) in Europe, supporting harmonization and interoperability across transport and tolling solutions.

By adhering to kSIST-TS FprCEN ISO/TS 25588:2026, industry players can ensure their image-based electronic fee collection systems are reliable, interoperable, and fully tested for compliance with evolving international best practices.

SLOVENSKI STANDARD
01-september-2026
Elektronsko pobiranje pristojbin - Sistemi na osnovi slik - Zgradba
preskuševalnega niza in namen preskušanja (ISO/DTS 25588:2026)
Electronic fee collection - Image-based systems - Test suite structure and test purposes
(ISO/DTS 25588:2026)
Elektronische Gebührenerhebung - Mautsystem basierend auf der Verarbeitung von
Fahrzeugbildern - Struktur der Prüffolge und Prüfabsicht (ISO/DTS 25588:2026)
Perception de télépéage - Systèmes de péage basés sur l'analyse d'images - Structure
de la suite d’essais et objectifs des essais (ISO/DTS 25588:2026)
Ta slovenski standard je istoveten z: FprCEN ISO/TS 25588
ICS:
35.240.60 Uporabniške rešitve IT v IT applications in transport
prometu
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

FINAL DRAFT
Technical
Specification
ISO/DTS 25588
ISO/TC 204
Electronic fee collection — Image-
Secretariat: ANSI
based systems —Test suite structure
Voting begins on:
and test purposes
2026-07-15
Perception de télépéage — Systèmes basés sur l'analyse d'images
Voting terminates on:
— Structure de la suite d’essais et objectifs des essais
2026-10-07
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/DTS 25588:2026(en) © ISO 2026

FINAL DRAFT
ISO/DTS 25588:2026(en)
Technical
Specification
ISO/DTS 25588
ISO/TC 204
Electronic fee collection — Image-
Secretariat: ANSI
based systems —Test suite structure
Voting begins on:
and test purposes
Perception de télépéage — Systèmes basés sur l'analyse d'images
Voting terminates on:
— Structure de la suite d’essais et objectifs des essais
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DTS 25588:2026(en) © ISO 2026

ii
ISO/DTS 25588:2026(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms and symbols . 2
5 Processes and variables under test . 3
6 Test setup . 3
6.1 General setup requirements .3
6.2 Laboratory test setup .4
6.3 On site test setup .5
6.4 Passage detection specific setup .5
6.5 Vehicle identification specific setup .5
6.6 Classification specific setup .6
7 Test suite structure and interfaces . 6
7.1 General .6
7.2 Passage detection interfaces .7
7.2.1 General .7
7.2.2 Purpose .7
7.2.3 Event generation .7
7.2.4 Interface requirements . . .7
7.3 Vehicle identification interfaces . .8
7.4 Vehicle classification interfaces .8
7.4.1 General .8
7.4.2 Event generation .8
7.4.3 Interface requirements . . .8
8 Test purposes . 9
8.1 General .9
8.2 Naming .9
8.3 Format .9
8.4 Laboratory tests .10
8.4.1 General .10
8.4.2 Test setup and geometries .10
8.4.3 Static identification tests . 12
8.4.4 Dynamic identification tests . . 13
8.5 On site passage detection . 13
8.5.1 General . 13
8.5.2 Test setup . 13
8.5.3 Detection of true positives .14
8.5.4 Detection: false positives . 15
8.5.5 Detection: false negatives . 15
8.6 On site Vehicle identification . 15
8.6.1 Test setup . 15
8.6.2 Identification by licence plate reading: true positives . 15
8.6.3 Identification: False positives with licence plate reading .16
8.6.4 Identification:True negatives .17
8.7 Classification: vehicle classification .18
8.7.1 Test setup .18
8.7.2 Classification: True positives .19
8.7.3 Classification: True negatives .19
8.7.4 Classification: False negatives . 20

iii
ISO/DTS 25588:2026(en)
Annex A (normative) Protocol Implementation eXtra Information for Test (PIXIT .21
Annex B (normative) Event data specification .24
Annex C (informative) Examples of real system implementations .25
Annex D (informative) Licence plate design and manufacturing considerations for image-based
vehicle identification .31
Bibliography .33

iv
ISO/DTS 25588:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 278,
Intelligent Transport Systems, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
ISO/DTS 25588:2026(en)
Introduction
[1]
ISO/TR 25221 identifies relevant characteristics of an image-based system and classifies these
characteristics in a number of processes that can be combined in various ways to perform services such
as electronic fee collection (EFC). The overall system performance or conformity to specifications depends
on the combination of the different processes (the architecture of the system) and the related business
processes, so it would be rather pointless to specify tests to measure it. However, test procedures can be
[1]
specified to determine conformity to specifications for the isolated processes that ISO/TR 25221 has
identified, as long as they can be accessed separately. This document specifies a component test suite for
image-based EFC systems.
Although this document is principally oriented at EFC systems, the test purposes herein specified are
considered general enough to be used to evaluate other image-based systems, such as:
— Parking
— Free-flow entry exit
— Gated parking
— Vehicle-based car park compliance checks and collection of evidence of non-compliance
— Vehicle-based roadside inspection or enforcement
— Traffic violation detection
— Roadside
— Vehicle-based
Key performance indicators (KPI) or numerical thresholds for parameters of EFC systems, including image-
[2]
based ones, are intended to be defined in a future edition of ISO/TS 37444 .

vi
FINAL DRAFT Technical Specification ISO/DTS 25588:2026(en)
Electronic fee collection — Image-based systems —Test suite
structure and test purposes
1 Scope
This document specifies the set-up of a testing system and the test suite structure and test purposes, i.e. tests
to assess conformity to specification for implemented processes of image-based electronic fee collection
(EFC) systems.
The test purposes specified in this document are solely for evaluating the behaviour of isolated processes in
an image-based EFC system.
The focus of the tests is related to the components and interfaces in the roadside system required for
fulfilling the needs of an image-based EFC system. Generic and overall tests related to the reliability and
qualitative capabilities of the complete charging point are outside of the scope of this document.
This document contains four annexes:
— Annex A, normative, that specifies the additional needed information that an implementation provides
to the tester to run tests;
— Annex B, normative, that specifies the format of the data to be produced for each test run;
— Annex C, informative, that collects a number of test purposes used to measure characteristics in
implemented systems;
— Annex D, informative, that collects licence plate design and manufacturing considerations.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 17573-2, Electronic fee collection — System architecture for vehicle related tolling — Part 2: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 17573-2 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
performance test
testing that simulates the expected workload on an application to assess factors such as transaction speed,
user behaviour, and system stability under normal or peak conditions

ISO/DTS 25588:2026(en)
3.2
identification
correct recognition of all characters contained in a licence plate and of the elements that identify the country
of registration of the vehicle
3.3
image-based EFC system identifier
device in the image-based EFC system that is in charge of a vehicle's licence plate identification (3.2)
3.4
reference space
volume where the image-based electronic fee collection (EFC) system is declared to be operating properly
3.5
actual distance
distance between the image-based EFC system identifier (3.3) and the vehicle's licence plate within which the
image-based EFC system is declared to be operating properly
4 Abbreviated terms and symbols
For the purposes of this document, the abbreviated terms in Table 1 apply.
Table 1 — Abbreviations
AD actual distance
AI artificial intelligence
ANPR automatic number plate recognition
EFC electronic fee collection
IBES image-based electronic fee collection system
LPN licence plate number
OCR optical character recognition
PD passage detection
PIXIT Protocol Implementation eXtra Information for Test
RS reference space
RSE roadside equipment
RSW reference space width
SUT system under test
SVM support vector machine
TCLS toll charger local system
VI vehicle identification
VC vehicle classification
For the purposes of this document, the symbols in Table 2 apply.
Table 2 — Symbols
Symbol Meaning
DET detection of true positive vehicles
CDI classification rate when classification is independent of detection and identification
CIC classification rate when classification happens after identification
CLI classification rate dependent on licence plate reading
CNR classification true negative rate
DFP detection of false positives rate

ISO/DTS 25588:2026(en)
TTabablele 2 2 ((ccoonnttiinnueuedd))
Symbol Meaning
ICI identification rate when classification precedes identification
IDI identification rate when detection precedes identification
LSI laboratory static identification
5 Processes and variables under test
[3]
Table 3, derived from Table 5 in ISO/TR 25221:2025 , shows the variables and processes that may be
subject to conformance test both in laboratory and in the field. The latter tests are at the frontier between
conformance and performance tests.
Table 3 — Process and variables subject to tests
Laboratory test Test in field
Process Variable
Testability Conditions Testability Conditions
Passage Detection rate No Yes Additional trusted
detection detection system
available
Detection of false No Yes Additional trusted
positives rate detection system
available
Detection of false No Yes Additional trusted
negatives rate detection system
available
Vehicle Identification rate Yes Optical charac- Yes OCR separately
identification when detection ter recognition testable
precedes identifica- (OCR) separately
tion testable
Identification rate Yes OCR separately Yes OCR separately
when classification testable testable
precedes identifica-
tion
Classification Classification rate Yes Classification Yes Additional trusted
when independent system separate- detection system
of detection and ly testable available
identification
Classification rate Yes Classification Yes Additional trusted
when classification system separate- identification sys-
happens after iden- ly testable tem available
tification
6 Test setup
6.1 General setup requirements
Subclauses 6.1 to 6.6 describe the general setup for laboratory and on site tests. Further details regarding
any specific tests are specified, if necessary, in the relative paragraphs.
Some assumptions are taken about licence plates, which shall be noted and reported when performing tests.
These include, but are not limited to:
— Modern cameras use both natural light and IR images in their detection process.
— All plates are retro-reflective. This is important to locate the plate on a vehicle. The retro-reflectivity
provides a high contrast rectangle to find.

ISO/DTS 25588:2026(en)
— Plate colour, fonts, images, labels are regulated to ensure the plate and its characters are clearly
identifiable.
— Plates are fitted to vehicles in a predictable manner in a predictable area.
— Frames and screws have a negative impact on ANPR, specifically obscuring the retro-reflectivity of the
plate.
— The measurement does not deal with plate-tampering to confuse detection, though the test as written
can be used for that purpose as well.
— Poor plate material quality and tooling have an impact on ANPR performance as plates age. The main
issues are:
— Delamination.
— Character print decal impacts sharpness of character edges.
The system under test (SUT) shall expose a fully operational replica of the roadside equipment (RSE) and
any centralized correlation component used in operation. When correlation among multiple RSE sources is
centralized, the same correlation logic shall be part of the SUT during tests to surface possible end-to-end
failure modes (e.g. race conditions, late event merging).
Specific requirements that the SUT shall provide for testing purposes are detailed in Annex A.
6.2 Laboratory test setup
Laboratory tests aim at verifying:
— the ability of the system to correctly acquire and recognize license plates under controlled lighting,
geometry, motion and occlusion conditions;
— the robustness of the ANPR process under variations of perspective, illumination, plate position and
simultaneous presence of multiple plates within the reference space (RS).
The tests shall be conducted in a controlled indoor environment, providing:
— controlled ambient light levels (0 lux to 10,000 lux depending on the test);
— free space to position plates and cameras at required geometries;
— mechanical equipment enabling precise placement and rotation of plates.
Laboratory instrumentation includes:
— A set of licence plates manufactured with materials compliant with current regulatory prescriptions (as
per the applicable highway code). Plates may be of any of the following types:
— rear plates for motor vehicles;
— front plates for motor vehicles;
— rear plates for motorcycles;
— plates for mopeds.
— An RS with the following characteristics:
— Adjustable incandescent (e.g. halogen) lamp with illuminance levels as required by the tests and
horizontal incidence angle of 13° ± 1° relative to plate axis.

ISO/DTS 25588:2026(en)
— Mechanical plate positioning system enabling rotation and placement of plates at multiple angles
and positions within the RS.
— For some specific requirements, a motion simulation system simulating relative motion between camera
and plate, equipped with optoelectronic trigger sensor to generate the capture event.
— A speed measurement device (e.g. radar or laser).
— A control workstation.
— Measuring equipment: surveyor’s measuring tape and steel tape measure.
— Test license plates (assorted series).
6.3 On site test setup
The SUT shall provide a fully functional replica of the operational system in an area capable of accommodating
transits by different vehicle classes.
Depending on the test purpose of the specific test, if correlation between outputs from multiple RSE units
is centralized, the SUT shall replicate the centralized system to demonstrate both the provenance of each
result and any potential weaknesses in the correlation process.
Unless stated otherwise, the on-site test fleet shall include at least: 1 motorcycle, 1 car, 1 light truck, 1 heavy
or articulated truck (if allowed by the site), optionally 1 bicycle and 1 pedestrian for false-positive checks.
As far as environmental conditions are concerned, daylight sessions are mandatory; dusk or night IR
sessions are recommended. Disturbances such as headlamps, reflections and wet surface should be included
when feasible.
For distances among vehicles and vehicles sequences, use separated flows (≈5 m gaps) and tailgating
scenarios (≤1 m, safety-permitting) at controlled speeds (e.g. 10–30 km/h on test track; higher speeds if
declared by the manufacturer and allowed by the site).
The geometry of the testing site shall reflect a realistic operational deployment (gantry, portal, side-
mounted, tripod, mobile, on-board) and be declared in the Protocol Implementation eXtra Information for
Test (PIXIT, see Annex A).
NOTE Realistic operational deployment" can be representative of an installation instance, or the most challenging
scenario of all the installation instance of a system.
Where the SUT relies on multiple sensors for detection and classification, each source shall be logged
separately, and the correlation algorithm shall be briefly described to the tester.
6.4 Passage detection specific setup
Based on the setup specified in 6.3, if the vehicle detection process is based on an RSE output, and the output
consists of more than a simple ON/OFF signal , the SUT shall provide access to an interface (hardware or
software) to assess the occurred detection (see Annex A).
Detection events shall be produced in a standardized format and time-stamped to detect generation delays
(see Annex B).
The aforementioned interface shall produce a single identifiable output for each passage.
6.5 Vehicle identification specific setup
Based on the setup specified in 6.3, if the vehicle identification process is based on a RSE output, the SUT
shall provide access to an hardware or software interface to visualize the identification of the vehicle.
If identification relies on RSE output, expose an interface to visualize identification results (e.g. licence
plate number (LPN) string, nationality, region, confidence score). When the SUT can identify other physical

ISO/DTS 25588:2026(en)
objects, provide a reference table describing all identifiable objects. One identifiable output per passage is
required.
Prior to testing, it shall be verified that the plate is fully contained in the declared area across a calibration
grid and typical angles; simulate low-speed motion to confirm absence of excessive motion blur.
6.6 Classification specific setup
Based on the setup specified in paragraph 6.3, if the vehicle classification process is based on an RSE output,
the SUT shall provide access to an hardware or software interface to visualize the occurred classification of
the vehicle.
The aforementioned interface shall produce a single identifiable output for each passage.
7 Test suite structure and interfaces
7.1 General
Figure 1 shows the physical and functional high-level system architecture for an image-based EFC system.
Focus is on the interfaces that are relevant for the scope of this document.
Figure 1 — High-level system architecture for an image-based EFC system
The image-based EFC system (IBES) shall provide a reference of the time zone when in operation and it shall
provide a synchronization reference status available during the whole test process.

ISO/DTS 25588:2026(en)
7.2 Passage detection interfaces
7.2.1 General
The passage detection interfaces consist of the three interfaces between the following physical objects:
— Inductive loop and Toll Charger Local System (TCLS). The inductive loop sends a message to the TCLS
whenever the inductive loop detects a vehicle. Based on the configuration of the loop, the loop may also
transmit data about the size of the vehicle.
— Vehicle presence radar and the TCLS. The radar sends a message to the TCLS whenever an object
with a size indicating that the object detected is a vehicle. The radar may also send data describing the
physical parameters of the physical object detected, see 7.4.
— Vehicle presence camera and the TCLS. The camera sends a message to the TCLS whenever a camera
has detected an object in the camera view that indicates that a vehicle is present in the toll lane.
7.2.2 Purpose
To define the interface specifications for detecting the passage of vehicles through tolling points, ensuring
accurate and reliable toll collection operations.
The SUT separation and distinction capabilities shall be assessed to avoid any possible fraudulent use of the
TCLS.
7.2.3 Event generation
Upon vehicle detection, the SUT shall generate an event containing:
— a timestamp,
— an optional lane identifier,
— the detection status (e.g success, failure),
— the utilized detection method.
If the detection process is more complex than a single ON/OFF signal, and a sequence of detection events is
identifiable, the timestamp generated shall indicate both the start and the stop event times.
The specification of the event data is specified in Annex B.
7.2.4 Interface requirements
7.2.4.1 General
The SUT may utilize sensors (e.g. loop detectors, infrared sensors, LIDAR, high-speed cameras) to detect
vehicles moving with different speed and across various lanes.
The speed ranges used in tests shall be compliant to those declared on the road signage, or those defined by
the national law.
7.2.4.2 Data format and transmission
Detection events shall be transmitted in a format known and understandable by the tester to the central
processing unit in real-time. The type and the characteristics of that format would be SUT-specific and are
not specified by this document.
When running tests, the event generation, among other data, shall be identified by a timestamp (specified in
Annex B), to detect possible delay between the time period of the detection process and the event generation.

ISO/DTS 25588:2026(en)
7.2.4.3 Error handling and redundancy
Missed detections shall be logged and flagged for review.
7.3 Vehicle identification interfaces
In image-based EFC systems, a vehicle identification interface is identified between the ANPR camera and
the TCLS. ANPR cameras may be used to capture both front and rear licence plates of the vehicle. Cameras
may also capture pictures of the complete vehicle (front and rear), to support verification of the vehicle
identification by additional detected information, e.g. the make and the colour of the vehicle, and to compare
them to the officially registered information that is associated to the licence plate.
7.4 Vehicle classification interfaces
7.4.1 General
Vehicle classification interfaces are identified between the following physical objects:
— Vehicle classification camera and TCLS. The camera sends pictures of the vehicle to the TCLS and
the TCLS uses the pictures possibly supported by artificial intelligence (AI) to classify the vehicle (e.g.
determining its size and number of axles). This enables the toll charger (TC) to verify that the vehicle
detected data correspond to those officially registered.
— Vehicle classification radar or lidar and TCLS. The radar or lidar sends vehicle detected data to the
TCLS and the TCLS uses that data (possibly supported by AI) to classify the vehicle (e.g. determining
its size and number of axles). This enables the TC to verify that the vehicle detected data correspond to
those officially registered.
7.4.2 Event generation
Upon vehicle detection, the SUT shall generate an event containing:
— a timestamp,
— a lane identifier,
— the detection status (e.g. success, failure),
— the utilized detection method.
If specific characteristics are used for the classification method (e.g. number of axles) the information shall
be provided in the generated event.
If a national classification scheme exists, and it is different from the one used by the TCLS, both classifications
shall be provided in the generated event, each of them associated with an accuracy evaluation and the
method utilized (e.g. the national scheme can be derived by an algorithm applied to the TCLS classification).
7.4.3 Interface requirements
7.4.3.1 Classification mechanism
The classification mechanism shall be described by the SUT.
In case of an AI, support vector machine (SVM) or neural network detection process, the basic logic behind
the classification process shall also be declared and described.
NOTE If the classification process is based on national characteristics (e.g. specific markings fixed to the vehicle,
sequence of letters in the licence plate), the TCLS is generally not able to operate on foreign vehicles.

ISO/DTS 25588:2026(en)
7.4.3.2 Data format and transmission
Classification events shall be transmitted in a specified format to the central processing unit in real-time, as
a single event or as a part of the picture metadata.
The test generated event shall be identified by a timestamp, to detect possible delays between the time
period of the classification process and the event generation. The format of the test generated events is
specified in Annex B.
7.4.3.3 Error handling and redundancy
Missed classification shall be logged and flagged for review.
In case of a classification score, an acceptability threshold shall be declared by the manufacturer, and all the
transits below the acceptability threshold shall be flagged for review.
8 Test purposes
8.1 General
Test purposes are specified in this document for the three capabilities of an image-based EFC system to
detect the passage of vehicles, to identify vehicles, and to classify vehicles.
These three capabilities are supposedly be tested independently, i.e. irrespective of the image-based EFC
system architecture.
The abbreviations in Table 1 will be used for naming the test purposes, see 8.2.
8.2 Naming
Test purposes are named in the following as XXYYYZZZ, where:
— [XX] indicates the process name, as per Table 1;
— [YYY] indicates the variable name, as per Table 2;
— [ZZZ] indicates the sequence number of the test purpose.
8.3 Format
Test purposes are specified in a table format, as shown by the proforma in Table 4, where the words in
boldface are entry names.
Table 4 — Test purpose proforma
Test Purpose name Test purpose description
Initial conditions Initial conditions
Repetitions Number of repetitions of the test purpose
Step sequence Step description
Sequence number Description of the step
Expected results Results expected. They may be expressed in terms of, e.g., number or percentage of true
positive results.
ISO/DTS 25588:2026(en)
8.4 Laboratory tests
8.4.1 General
The following tests are intended to be performed in a closed laboratory with the characteristics and setups
as specified in 6.2. Laboratory tests are only aimed at identifying the vehicle by correctly reading its licence
plate [see Identification (of a licence plate)].
All laboratory tests shall be conducted with:
— camera aligned frontally to the licence plate (a limited lateral offset is allowed to cater for a lane width);
— installation height = manufacturer declared height or max laboratory height;
— licence plate distance configured to maintain the declared actual distance (AD).
8.4.2 Test setup and geometries
The following geometric parameters shall be declared by the manufacturer and used for testing (see
Figure 2):
— H: maximum height of the camera,
— AD: actual distance between camera and licence plate,
— LO: lateral offset between the camera and the licence plate,
— GD: ground distance between the licence plate and the plane perpendicular to the licence plate where the
camera is positioned.
ISO/DTS 25588:2026(en)
Figure 2 — Geometric parameters for laboratory tests
The same geometrical terms apply for the evaluation of:
— RSW (Reference Space Width at 0 lux),
— Identification depth, the maximum GD for which valid identification is verified,
— Limit positions used in static recognition tests. These are the points, in the coordinates (x,y,z) as shown
in Figure 2, where the plate is positioned:
— The centre lane position at ground level (GD,0,0)
— The centre lane position at half of the maximum height of the camera (GD, 0, H/2)
— The centre lane position at maximum height of the camera (GD, 0, H)
— The right displacement from the centre lane at ground level (GD, LO, 0)
— The right displacement from the centre lane at half of the maximum height of the camera (GD, LO,
H/2)
— The right displacement from the centre lane at maximum height of the camera (GD, LO, H)
— The left displacement from the centre lane at ground level (GD, -LO, 0)
— The left displacement from the centre lane at half of the maximum height of the camera (GD, -LO,
H/2)
— The left displacement from the centre lane at maximum height of the camera (GD, LO, -H)

ISO/DTS 25588:2026(en)
8.4.3 Static identification tests
Static identification tests, specified in Table 5, Table 6 and Table 7, are aimed at measuring the ability of
identifying static licence plates in different light conditions.
Table 5 — TP VILSI001: Identification of static licence plate in the laboratory in 0 lux illumination
conditions
VILSI001 Identification of vehicles in 0 lux light conditions
Initial conditions Position each licence plate at the nine limit points within the RS.
Consider three azimuth displacements for the licence plate: 0°, +αmax, -αmax.
Set illuminance to 0 lux.
Repetitions Repeat each step for each limit point and each azimuth angle for 100 times, for a total
of 2700 identifications
Step sequence Step description
1 Position the licence plate at one limit point at one azimuth displacement
2 Identify the licence plate and save the result
Expected results For each position and each azimuth displacement, the percentage of valid identifica-
tions shall be better or equal to the expected value.
Table 6 — TP VILSI002: Identification of static licence plate in the laboratory in 10000 lux illumination
conditions
VILSI002 Identification of vehicles in
...