SIST-TS CEN ISO/TS 17444-1:2018

Electronic fee collection - Charging performance - Part 1: Metrics (ISO/TS 17444-1:2017)

This document defines metrics for the charging performance of electronic fee collection (EFC) systems
in terms of the level of errors associated with charging computation.
This document is a toolbox standard of metrics. The detailed choice of metrics depends on the
application and the respective context.
This document describes a set of metrics with appropriate definitions, principles and formulations,
which together make up a reference framework for the establishment of requirements for EFC systems
and their later examination of the charging performance.
The charging performance metrics defined in this document are intended for use with any Charging
Scheme, regardless of its technical underpinnings, system architecture, tariff structure, geographical
coverage, or organizational model. They are defined to treat technical details that can be different
among technologies and vendors or vary over time as a “black box”.
They focus solely on the outcome of the charging process, i.e. the amount charged in relation to a premeasured
or theoretically correct amount, rather than intermediate variables from various components
as sensors, such as positioning accuracy, signal range, or optical resolution. This approach ensures
comparable results for each metric in all relevant situations.
The metrics are designed to cover the information exchanged on the Front End interface and the
interoperability interfaces between Toll Service Providers, Toll Chargers and Road Users as well as on
the End-to-End level.
Metrics on the following information exchanges are defined:
— Charge Reports;
— Toll Declarations;
— Billing Details and associated event data;
— Payment Claims on the level of toll service user accounts;
— User Accounts;
— End-to-End Metrics which assess the overall performance of the charging process.
The details on the rationale of this choice are described in 5.1.
The proposed metrics are specifically addressed to protect the interests of the actors in a toll system,
such as Toll Service Providers, Toll Chargers and Road Users. The metrics can be used to define
requirements (e.g. for requests for proposals) and for performance assessment.
This document recognises two types of situations where a performance assessment is necessary:
a) when an assessment is carried out during a limited time span, such as when formulating
requirements and assessing systems for acquisition purposes, conducting acceptance testing as
assessment is referred to as an evaluation;
b) when an assessment is needed as an ongoing supervision process, throughout the lifetime of
a system, in order to validate contracted service levels, to identify fraud or malfunction, or to
support ongoing maintenance and performance improvement processes. This type of assessment is
referred to as monitoring.

Elektronische Gebührenerhebung - Abbuchungsdurchführung - Teil 1: Metriken (ISO/TS 17444-1:2017)

Perception du télépéage - Performance d'imputation - Partie 1: Métrique (ISO/TS 17444-1:2017)

Elektronsko pobiranje pristojbin - Uspešnost zaračunavanja - 1. del: Meritve (ISO/TS 17444-1:2017)

Ta dokument določa meritve za uspešnost zaračunavanja sistemov za elektronsko pobiranje pristojbin (EFC) na podlagi ravni napak, povezanih z izračuni zaračunavanja.
Ta dokument je osnovni standard meritev. Podrobna izbira meritev je odvisna od
uporabe in povezanega konteksta.
Ta dokument opisuje sklop meritev z ustreznimi opredelitvami, načeli in ubeseditvami, ki skupaj sestavljajo referenčni okvir za določitev zahtev za sisteme za elektronsko pobiranje pristojbin ter poznejši pregled njihove uspešnosti zaračunavanja.
Meritve uspešnosti zaračunavanja iz tega dokumenta so namenjene uporabi v zvezi s katerim koli sistemom zaračunavanja, ne glede na njegovo tehnično zasnovo, sistemsko arhitekturo, tarifno strukturo, geografsko pokritost ali organizacijski model. Določijo se za obravnavanje tehničnih podrobnosti, ki se lahko razlikujejo med tehnologijami in ponudniki ali se sčasoma spreminjajo kot »črna skrinjica«.
Osredotočajo se izključno na rezultat postopka zaračunavanja, tj. na znesek, ki se zaračuna glede na vnaprej izmerjen ali teoretično pravilen znesek, in ne na vmesne spremenljivke, ki izhajajo iz različnih sestavnih delov senzorjev, kot je položajna natančnost, doseg signala ali optična ločljivost. Ta pristop zagotavlja primerljive rezultate za vsako meritev v vseh ustreznih primerih.
Meritve so namenjene obravnavanju informacij, izmenjanih v okviru čelnega vmesnika in
vmesnikov interoperabilnosti med izvajalci storitev cestninjenja, pobiralci cestnine in uporabniki cest ter tudi na celotni ravni.
Opredeljene so meritve v zvezi z naslednjimi izmenjavami informacij:
– poročila o zaračunavanju,
– izjave o plačilu cestnine,
– podatki o obračunavanju in povezani podatki o dogodku,
– zahtevki za plačilo na ravni uporabniških računov storitve pobiranja cestnin,
– uporabniški računi,
– celotne meritve, ki ocenijo splošno delovanje postopka zaračunavanja.
Podrobnosti o utemeljitvi te izbire so navedene v točki 5.1.
Predlagane meritve so posebej namenjene zaščiti interesov udeležencev v sistemu cestninjenja, kot so izvajalci storitev cestninjenja, pobiralci cestnine in uporabniki cest. Meritve je mogoče uporabiti za opredelitev zahtev (npr. za zahteve za predloge) in ocenjevanje uspešnosti.
Ta dokument določa dve vrsti primerov, v katerih je potrebna ocena uspešnosti:
a) kadar se ocena izvaja v omejenem časovnem obdobju, na primer pri oblikovanju
zahtev in oceni sistemov za namene pridobivanja, preskušanju ustreznosti v okviru postopka začetka obratovanja ali v okviru postopka certificiranja, pri čemer se vse te vrste ocene imenujejo vrednotenje,
b) kadar je ocena potrebna v okviru stalnega nadzornega postopka v celotni življenjski dobi
sistema, da se validirajo ravni pogodbene storitve, opredeli goljufija ali okvara ali
podprejo stalni postopki vzdrževanja in izboljšave uspešnosti. Ta vrsta ocene se imenuje spremljanje.

General Information

• Status: Withdrawn
• Publication Date: 08-Jan-2018
• Withdrawal Date: 15-Aug-2023
• ICS: 03.220.20 - Road transport
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ITC - Information technology
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 24-Jul-2023
• Due Date: 16-Aug-2023
• Completion Date: 16-Aug-2023
• Directive: 2004/52/EC - Interoperability of electronic road toll systems in the Community
• Mandate: M/338 - Standardisation mandate to CEN, CENELEC and ETSI in support of interoperabilty of electonic road toll systems in the community
• Ref Project: CEN ISO/TS 17444-1:2017 - Electronic fee collection - Charging performance - Part 1: Metrics (ISO/TS 17444-1:2017)

Relations

• Replaces: SIST-TS CEN ISO/TS 17444-1:2013 - Electronic fee collection - Charging performance - Part 1: Metrics (ISO/TS 17444-1:2012)
• Effective Date: 01-Feb-2018

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS CEN ISO/TS 17444-1:2018
01-februar-2018
1DGRPHãþD
SIST-TS CEN ISO/TS 17444-1:2013
(OHNWURQVNRSRELUDQMHSULVWRMELQ8VSHãQRVW]DUDþXQDYDQMDGHO0HULWYH
,6276
Electronic fee collection - Charging performance - Part 1: Metrics (ISO/TS 17444-1:2017)
Elektronische Gebührenerhebung - Abbuchungsdurchführung - Teil 1: Metriken (ISO/TS
17444-1:2017)
Perception du télépéage - Performance d'imputation - Partie 1: Métrique (ISO/TS 17444-
1:2017)
Ta slovenski standard je istoveten z: CEN ISO/TS 17444-1:2017
ICS:
03.220.20 Cestni transport Road transport
35.240.60 Uporabniške rešitve IT v IT applications in transport
prometu
SIST-TS CEN ISO/TS 17444-1:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN ISO/TS 17444-1:2018

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SIST-TS CEN ISO/TS 17444-1:2018


CEN ISO/TS 17444-1
TECHNICAL SPECIFICATION

SPÉCIFICATION TECHNIQUE

October 2017
TECHNISCHE SPEZIFIKATION
ICS 03.220.20; 35.240.60 Supersedes CEN ISO/TS 17444-1:2012
English Version

Electronic fee collection - Charging performance - Part 1:
Metrics (ISO/TS 17444-1:2017)
Perception du télépéage - Performance d'imputation - Elektronische Gebührenerhebung -
Partie 1: Métrique (ISO/TS 17444-1:2017) Abbuchungsdurchführung - Teil 1: Metriken (ISO/TS
17444-1:2017)
This Technical Specification (CEN/TS) was approved by CEN on 27 August 2017 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 17444-1:2017 E
worldwide for CEN national Members.

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Contents Page
European foreword . 3

2

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European foreword
This document (CEN ISO/TS 17444-1:2017) has been prepared by Technical Committee ISO/TC 204
“Intelligent transport systems” in collaboration with Technical Committee CEN/TC 278 “Intelligent
transport systems” the secretariat of which is held by NEN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN ISO/TS 17444-1:2012.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO/TS 17444-1:2017 has been approved by CEN as CEN ISO/TS 17444-1:2017 without any
modification.

3

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SIST-TS CEN ISO/TS 17444-1:2018
TECHNICAL ISO/TS
SPECIFICATION 17444-1
Second edition
2017-09
Electronic fee collection — Charging
performance —
Part 1:
Metrics
Perception du télépéage — Performance d'imputation —
Partie 1: Métrique
Reference number
ISO/TS 17444-1:2017(E)
©
ISO 2017

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COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 3
4 Abbreviated terms . 6
5 Definition of charging performance metrics . 7
5.1 General . 7
5.2 Metric Identification.10
5.3 End-to-End Metrics .11
5.4 User Account Metrics .11
5.5 Payment Claim Metrics .12
5.6 Billing Details Metrics .13
5.7 Toll Declaration Metrics .15
5.7.1 General.15
5.7.2 Metrics relevant for all schemes .16
5.7.3 Metrics only applicable to discrete schemes .16
5.7.4 Metrics applicable to continuous schemes .17
5.8 Charge Report Metrics .18
5.8.1 General.18
5.8.2 Metrics relevant for all schemes .18
5.8.3 Metrics only applicable to discrete schemes .19
5.8.4 Metrics applicable to continuous schemes .20
Annex A (informative) Defining Performance Requirements .21
Bibliography .25
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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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
This second edition cancels and replaces the first edition (ISO/TS 17444-1:2012), which has been
revised with the following changes:
— editorial and formal corrections, as well as changes, to improve readability;
— updated terminology.
A list of all parts in the ISO/TS 17444 series can be found on the ISO website.
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Introduction
Electronic tolling systems are complex distributed systems involving mission-critical technology
such as dedicated short-range communication (DSRC) and global navigation satellite systems (GNSS)
both subject to a certain random behaviour that may affect the computation of the charges. Thus, in
order to protect the interests of the different involved stakeholders, in particular Service Users and
Toll Chargers, it is essential to define metrics that measure the performance of the system as far as
computation of charges is concerned and ensure that the potential resulting errors in terms of size and
probability are acceptable. These metrics will be an essential tool when establishing requirements for
the systems and also for examination of the system capabilities both during acceptance and during the
operational life of the system.
In addition, in order to ensure the interoperability of different systems, it will be necessary to agree on
common metrics to be used and on the actual values that define the required acceptable performances.
Although this is not covered in this document, it is covered in ISO/TS 17444-2.
Toll schemes take on various forms as identified in ISO 17575 (all parts) and ISO 14906. In order to
create a uniform performance metric specification, toll schemes are grouped into two classes, based
on the character of their primary charging variable: Charging based on discrete events (charges when
a vehicle crosses or stands within a certain zone), and those based on a continuous measurement
(duration or distance).
The following are examples of discrete (event-based) toll schemes.
— Single object charging: a road section, bypass, bridge, tunnel, mountain pass or even a ferry, charged
per passage; most tolled bridges belong to this category.
— Closed road charging: a fixed amount is charged for a certain combination of entry and exit on a
motorway or other closed road network; many of the motorways in Southern Europe belong to this
category.
— Discrete road links charging: determined by usage of specified road links, whether or not used in
their entirety.
EXAMPLE German heavy goods vehicle (HGV) charge.
— Charging for cordon crossing: triggered by passing in or out through a cordon that encircles a city
core, for example.
EXAMPLE Stockholm congestion charging.
The following are examples of continuous toll schemes.
— Charging based on direct distance measurement: defined as an amount per kilometre driven.
EXAMPLE Switzerland’s HGV charge; US basic vehicle miles travelled approach.
— Charging based on direct distance measurement in different tariff zones or road types: defined as
an amount per kilometre driven, with different tariffs applying in different zones or on different
road types. This is a widely discussed approach, also known as Time-Distance-Place charging, and
is under consideration in many European countries.
EXAMPLE OReGO, the pilot programme in Oregon, is an example from North America.
— Time in use charge: determined by the accumulated time a vehicle has been in operation, or,
alternatively, by the time the vehicle has been present inside a predefined zone.
In all these examples of toll schemes, tolls may additionally vary as a function of vehicle class
characteristics such as trailer presence, number of axles, taxation class, operating function, and
depending on time of day or day of week, so that, for example, tariffs are higher in rush hour and lower
on the weekends.
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With this degree of complexity, it is not surprising to find that the attempts to evaluate and compare
technical solutions for Service User charging have been made on an individual basis each time a
procurement or study is initiated, and with only limited ability to reuse prior comparisons made by
other testing entities.
The identification of different types of schemes as proposed in ISO 17575 (all parts) and their grouping in
the mentioned two classes is described in Table 1, which also identifies the examples mentioned above.
Table 1 — Tolling scheme designs grouped according to Scheme categories
Examples Scheme type ISO 17575 category
Single object charging Discrete Sectioned roads pricing
Closed road charging Discrete Sectioned roads pricing
Discrete road links charging Discrete Sectioned roads pricing
Charging for cordon crossing Discrete Cordon pricing
Time in use charge Continuous Area pricing — time
Cumulative distance charge Continuous Area pricing — distance
Charging for cumulative distance (or time) in different Continuous Area pricing — distance
zones (or by road type)
No toll schemes are purely continuous. At the very least, a system must be able to stop accumulating
charges when it leaves a jurisdiction in which a charge is due, and resume charging when it returns
or enters another. Additionally, many Charging Schemes are set up so that the tariff is modified using
discrete parameters, such as spatial zones, time spans, vehicle classes, etc. Under those circumstances,
each unit of distance or time costs a different amount depending, for example, on whether it takes
place inside or outside an area, such as a city, whether a trip takes place in rush hour or at night, or
depending on what type of vehicle is used. In this document references to a “continuous system” have to
be understood as those systems having some continuous behaviour even though they can also integrate
some discrete nature. References to “discrete systems” are limited to those systems that are purely
discrete.
In these schemes, all the discrete parts (zones, cordons, events, time, vehicle class, etc.) that a system has
to identify are translated into a particular tariff (e.g. price per kilometre) that has to be applied to the
measured continuous variable (e.g. distance travelled) resulting in another continuous parameter, money.
Some features of discrete and continuous toll schemes that are of relevance for the definition of metrics
proposed in this document are analysed below.
Discrete toll schemes
In a discrete toll scheme, distinct events are associated with the identification of Charge Objects. It
can happen that a vehicle crossed a cordon, passed a bridge or was present in an area on a given day.
An event that takes place can either be correctly recorded by the system or can be missed. However,
there is also the possibility that an event is recorded even though it did not actually take place. This is
summarized in the following matrix in Table 2.
Table 2 — Theoretical event decision matrix for discrete schemes
System detects charge object detection
Event Matrix
Yes No
Missed Recognition
Correct
Yes
Charging
(Undercharging)
Charge object detection
takes place
False Positive
Correct
No
Non-charging
(Overcharging)
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In Table 2 are two successful scenarios (Correct Charging and Correct Non-charging) and two
unsuccessful (Missed Recognition and False Positive). The unsuccessful scenarios have very different
consequences. A Missed Recognition, i.e. a charge object detection that takes place but is not recorded
by the system, implies an undercharging, as the Service User is not charged.
In the case of False Positive, a vehicle that is not using the toll domain is being charged for an event which
did not take place. This implies an overcharging which is in violation of the legal rights of the Service
User, and ultimately risks eroding trust in the system.
This document therefore makes a distinction between the two types of errors and defines associated
metrics to protect the interests of the Toll Charger and Service Users in terms of the allowed probabilities
of those events.
Continuous toll schemes
A continuous toll scheme is one where the charge is calculated using accumulated time or distance the
base tariff is applied to.
Note that a discrete scheme with a large number of Charge Objects would lead to charging incremental
variations, and is hence approaching a continuous scheme (the higher the number of events the closer
such schemes are to a continuous scheme). In any case, this would still formally be a discrete scheme.
In discrete toll schemes errors are binary: either a charge object detection is correctly recorded or it
is not. However, in continuous schemes the errors are relatively small and they vary continuously, i.e.
those errors are real (in the mathematical sense) variables instead of logical variables. Figure 1 shows
different levels of dispersion and different directions of bias. The horizontal axis shows the size of
the errors and the vertical axis the probability density. The vertical line in each plot represents zero
charging error. Note that it is possible to have small dispersion (i.e. a small standard deviation) that still
biases charging high or low (i.e. not accurate).
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Figure 1 — Idealized plots of error distribution of four different result sets
In Figure 1, Chart A symbolizes the results from a Front End with more dispersion than that used for
Chart B. For all parties involved, B is preferable to A. Charts C and D show two Front Ends with the
same standard deviation, but where Chart C shows one that is consistently undercharging, and Chart D
shows one that is consistently overcharging road usage.
By defining an Accepted Charging Error Interval to the chart, with a lower and an upper bound, as shown
in Figure 2, it is possible to state that for a system to be accepted it must perform so that some minimum
share of the measurements fall inside the interval specified as accepted by the Toll Charger.
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Figure 2 — Definition of Accepted Error Interval
Setting the upper and lower bounds far apart relaxes requirements on the equipment evaluated, while
setting them closer together would make the requirement to fulfil harder to pass. By setting the upper
bound closer to the correct charging value and the lower bound farther away, the Toll Charger can
formalize exactly how much more important it is to avoid overcharging than it is to avoid undercharging.
By defining those bounds (Accepted Charging Error Interval) together with the probabilities to be
inside and above those bounds the Toll Charger can define precisely its requirements distinguishing
between overcharging and undercharging. In reality no scheme is purely continuous and all foreseeable
continuous schemes have some discrete components. The discrete nature of real systems can be either
associated to the physical border of a country (continuous measurements take place only if vehicle is
within the country) or to the identification of different urban zones or roads where different tariffs
(per unit of time or distance) are applied.
Thus, continuous schemes have associated metrics that are specific to those continuous systems but
the ones identified for discrete schemes are also applicable.
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SIST-TS CEN ISO/TS 17444-1:2018
TECHNICAL SPECIFICATION ISO/TS 17444-1:2017(E)
Electronic fee collection — Charging performance —
Part 1:
Metrics
1 Scope
This document defines metrics for the charging performance of electronic fee collection (EFC) systems
in terms of the level of errors associated with charging computation.
This document is a toolbox standard of metrics. The detailed choice of metrics depends on the
application and the respective context.
This document describes a set of metrics with appropriate definitions, principles and formulations,
which together make up a reference framework for the establishment of requirements for EFC systems
and their later examination of the charging performance.
The charging performance metrics defined in this document are intended for use with any Charging
Scheme, regardless of its technical underpinnings, system architecture, tariff structure, geographical
coverage, or organizational model. They are defined to treat technical details that can be different
among technologies and vendors or vary over time as a “black box”.
They focus solely on the outcome of the charging process, i.e. the amount charged in relation to a pre-
measured or theoretically correct amount, rather than intermediate variables from various components
as sensors, such as positioning accuracy, signal range, or optical resolution. This approach ensures
comparable results for each metric in all relevant situations.
The metrics are designed to cover the information exchanged on the Front End interface and the
interoperability interfaces between Toll Service Providers, Toll Chargers and Road Users as well as on
the End-to-End level.
Metrics on the following information exchanges are defined:
— Charge Reports;
— Toll Declarations;
— Billing Details and associated event data;
— Payment Claims on the level of toll service user accounts;
— User Accounts;
— End-to-End Metrics which assess the overall performance of the charging process.
The details on the rationale of this choice are described in 5.1.
The proposed metrics are specifically addressed to protect the interests of the actors in a toll system,
such as Toll Service Providers, Toll Chargers and Road Users. The metrics can be used to define
requirements (e.g. for requests for proposals) and for performance assessment.
This document recognises two types of situations where a performance assessment is necessary:
a) when an assessment is carried out during a limited time span, such as when formulating
requirements and assessing systems for acquisition purposes, conducting acceptance testing as
© ISO 2017 – All rights reserved 1

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SIST-TS CEN ISO/TS 17444-1:2018
ISO/TS 17444-1:2017(E)

part of the commissioning process, or as part of a certification procedure. Any one of these types of
assessment is referred to as an evaluation;
b) when an assessment is needed as an ongoing supervision process, throughout the lifetime of
a system, in order to validate contracted service levels, to identify fraud or malfunction, or to
support ongoing maintenance and performance improvement processes. This type of assessment is
referred to as monitoring.
NOTE 1 Definitions and metrics proposed in this document are intended for both situations.
The following are not covered by this document.
— This document does not propose specific numeric performance bounds, or average or worst-case
error bounds in percentage or monetary units. Those decisions are left to the Toll Charger (or to
agreements between Toll Charger and Service Provider), while providing a way to be sure that there
is a consistent framework for describing system requirements when writing Request for proposals,
for system comparisons during acquisition, for test results, for Service Level Agreements, and
ongoing (post-deployment) performance monitoring.
— This document does not consider the evaluation of the expected performance of a system based on
modelling and measured data from a trial at another place.
— This document does not consider the specification of a common reference system which would be
required for comparison of performance between systems.
— This document does not specify metrics on parts of tolling systems other than the charging process
chain, such as:
— enforcement system;
— security measures.
— This document does not cover metrics on parts of the charging processing chain which are considered
an internal matter of one of the interoperability partners:
— equipment performance, e.g. for on-board equipment, road-side equipment or data centres such
as signal range, optical resolution or computing system availability;
— position performance metrics: The quality of data generated by position sensors is considered
as an internal aspect of the Front End. It is masked by correction algorithms, filtering, inferring
of data and the robustness of the Charge Object recognition algorithms.
Even though some of these aspects have a direct impact on charging perfor
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