ISO/PAS 8235:2024

Publicly
Available
Specification
ISO/PAS 8235
First edition
Road vehicles — Ergonomic aspects
2024-11
of human vehicle interactions —
Taxonomy for the classification of
adaptive interactive vehicle systems
Véhicules routiers — Aspects ergonomiques des interactions
homme-véhicule — Taxonomie pour la classification des systèmes
interactifs adaptatifs pour véhicules
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Application . 4
5 Classification of the type of adaptivity for vehicle systems . 4
5.1 General .4
5.2 Type 0 – no adaptation .5
5.2.1 General description . .5
5.2.2 Example .5
5.3 Type 1 – saved adaptation .5
5.3.1 General description .5
5.3.2 Example .6
5.4 Type 2 – predefined adaptation .6
5.4.1 General description .6
5.4.2 Example .7
5.5 Type 3 – Adaption based on real-time learning .7
5.5.1 General description .7
5.5.2 Example .8
5.6 Type 4 – Adaptation based on real-time learning and interpretations .8
5.6.1 General description .8
5.6.2 Example .9
5.7 Summary .9
Annex A (informative)  .11
Bibliography . 17

iii
Foreword
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Ergonomics.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
With increasing technical feasibility of artificial intelligence (AI), more companies are integrating AI-based
adaptivity and personalization into vehicle systems to adapt their behavior and/or content to the needs
or expectations of individual users or groups of users. This enables vehicle systems to match individual
user preferences and assist and ease execution of non-driving related functions. For the driving context,
this offers the potential to reduce workload and distraction by helping users to handle large amounts of
information within road vehicles. Nevertheless, there is no uniform classification for the capacities and
characteristics of the type of adaptivity for vehicle systems.
This may lead to several risks of misunderstandings and unmatched expectations for different stakeholders
as well as for the end user. If the type of the adaptivity is not clear to the end user, it can lead to uncertainty
and a lack of transparency, predictability, algorithmic awareness, and understanding of the vehicle
system’s capacities and limits. Developers as well as the manufacturers as stakeholders also bear the
risks of misunderstandings or unmatched expectations within all phases of the development process
(ISO/IEC/IEEE 29148).
The ISO 8235 was developed to classify vehicle functions regarding their type of adaptivity and parameters
used to achieve the adaptations.
Standardizing the types of adaptation of vehicle systems serves the following purposes:
a) enables end users to assess the extent and limitations of adaptation specified by the manufacturers,
suppliers and researchers,
b) provides an unambiguous framework for the specification of adaptive vehicle systems and the technical
differentiation of the respective types of adaptivity in the requirement phase,
c) provides clarity and transparency in communication on the topic of adaptive vehicle systems for
manufacturers, suppliers as well as researchers,
d) reduces uncertainty about the capacity and limitations associated with non-transparent black box
technology solutions for the manufacturers,
e) prevents misunderstandings and deviating expectations between development partners of adaptive
vehicle systems and therefore,
f) prevents unnecessary effort, duplicate work and costs in the development and evaluation of adaptive
vehicle systems.
v
Publicly Available Specification ISO/PAS 8235:2024(en)
Road vehicles — Ergonomic aspects of human vehicle
interactions — Taxonomy for the classification of adaptive
interactive vehicle systems
1 Scope
This document provides a taxonomy to classify the type of adaptivity within vehicle systems. The
taxonomy includes five types ranging from no adaptation (type 0) to adaptations based on interpreted user
characteristics and context data (type 4). This document provides definitions of the five types of adaptation
and explains adaptation in a consistent and coherent manner. By offering definitions and descriptions of the
five types, this document can be used to classify the adaptivity within vehicle systems according to the types.
This document is intended to be applied to all components of vehicle systems that the driver and/or other
occupants interact with either while driving or while parked. This includes vehicle information systems,
communication systems, for example, navigation systems or mobile devices connected to the vehicle
infrastructure, traffic and travel information (TTI) systems, as well as vehicle comfort systems, for example,
climate control, massage, or ambient lighting. The taxonomy is also applicable to third-party software
provided by third-party suppliers that is displayed and/or operated in the vehicle.
The taxonomy can also be applied to interactive exterior elements, like windscreen wipers or pedestrian
communication devices and non-driving-related functions that are novel to future vehicles in the context of
automated driving, such as playing a video.
The information and communication vehicle systems described in this document exclude driving-operation
or driving-assistance systems. Consequently, safety-related functions governed by Automotive Safety
Integrity Level (ASIL) specifications (ISO 26262) are not addressed. Implementation and validation of data
collection/detection are also beyond the scope. Additionally, priority handling, as well as varying legal
regulations across countries, are not covered in the taxonomy.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
adaptable vehicle system
interactive system within a vehicle that can change its behaviour and/or content triggered by configurations
from the user
[SOURCE: Reference [8]]
3.2
adaptation
proactive changes in the system behaviour and/or content based on user configurations, pre-defined rules
or self-learned system rules
3.3
adaptive vehicle system
interactive system within a vehicle that can proactively change its behaviour and/or content triggered by
certain events without intervention from the user
Note 1 to entry: Adapted from Reference [7].
3.4
black box
idealized mechanism that accepts inputs and produces outputs, but is designed such that an observer cannot
see inside the box or determine exactly what is happening inside that box
Note 1 to entry: This term can be contrasted with glass box (3.13).
[SOURCE: ISO/IEC 18031:2011, 3.6]
3.5
context data
influencing factors from both, the general context of use as well as situational factors and conditions
resulting from the surrounding environment
3.6
data processing
manner in which real time inputs are analysed by the system to decide on the suitable reaction and/or
adaptation (3.2)
3.7
enhanced data
data that has been processed to enhance its quality, accuracy, or relevance
Note 1 to entry: This involves cleaning, filtering, combining data from multiple sources and adding contextual
information before storage.
3.8
exterior element
element outside the vehicle with the function of taking on different states
3.9
individualization
modification of interaction and presentation of information to suit individual capabilities, needs and
preferences of users
[SOURCE: ISO 9241-129:2010, 3.3, modified — "preferences" was added to the definition.]
3.10
non-driving related function
secondary (3.15), or tertiary task (3.17) the user can execute inside a vehicle that is not related to the primary
driving task (3.12)
3.11
preference
predilection of a user pertaining to a vehicle system
Note 1 to entry: This includes the user's tastes, likes and dislikes with respect to the vehicle system and its properties.
[SOURCE: ISO/IEC TR 15938-8:2002, 2.2.2.41, modified — The original term was user preferences, in the
definition predilection replaces preference and the note to entry was originally part of the definition.]

3.12
primary driving task
activity that the driver undertakes to maintain longitudinal and lateral vehicle control within the traffic
environment
[SOURCE: ISO 17287:2003, 3.2.17]
3.13
priority
relative importance of two or more messages which determines their ranking in a time sequence or emphasis
of presentation
[SOURCE: ISO 16951:2021, 3.10]
3.14
real-time learning
process of using live data input to continuously improve the vehicle system algorithms based on continuous
learning
3.15
secondary task
function that increases the safety for the driver, the car and the environment
EXAMPLE Setting turning signals or activating the windshield wipers.
[SOURCE: Reference [9]]
3.16
stakeholder
person or organisation that may influence a decision or activity, may be influenced by it, or may have the
impression of being influenced by it
Note 1 to entry: Stakeholders may include: users, purchasers, system owners or managers, and persons indirectly
influenced by the operation of a system, product or service.
Note 2 to entry: Different stakeholders may have different needs, requirements and/or expectations.
[SOURCE: ISO 9241-11:2018, 3.1.9, modified — Affect(ed) was replaced by influence(d).]
3.17
tertiary task
any function regarding entertainment and information systems
[SOURCE: Reference [9]]
3.18
trait
temporal stable and cross-situational consistent characteristics of the user's personality
[SOURCE: Reference [10]]
3.19
user identification
identification of user groups, such as family members sharing the same car key, and the identification
of numerical identifiers, such as 1, 2, 3, etc., that users can utilize independently, is not limited to the
identification of individuals by methods such as facial recognition
3.20
user interface
all components of an interactive system (software or hardware) that provide information and controls for
the user to accomplish specific tasks with the interactive system
[SOURCE: ISO 9241-129:2010, 3.9]

4 Application
The taxonomy can be applied to classify systems or components within vehicle systems based on their type
of adaptivity. As Figure 1 illustrates, vehicle systems are a comprehensive assembly consisting of several
components. Each of these vehicle systems, for example, an infotainment system is further subdivided into
several subsystems, e.g. a navigation system. Within each subsystem, various functions are organized, such
as the destination input function or route guidance function within a navigation system.
Figure 1 — Conceptual architecture of vehicle systems
The taxonomy is intended for application to all components of vehicle systems, classifying the type of
adaptation to the driver and/or other vehicle occupants, either while driving, standstill or being parked.
The taxonomy can also be applied to interactive exterior elements, like windscreen wipers or pedestrian
communication devices and non-driving-related functions that are novel to future vehicles in the context of
automated driving, such as playing a video. Functions provided by third-party suppliers are also included in
the intended application.
When specifying the adaptivity type for a vehicle system, the documentation shall transparently state
the relevant component, tailored to the appropriate target audience, e.g. for developers in the technical
specification or for end users in the product description.
If the classified vehicle system includes multiple components, the documentation shall provide a clear
description indicating the relevant component and whether other components of the vehicle system have a
different adaptivity type. This transparency ensures a relatable application of the taxonomy and enables the
classified adaptivity types of vehicle systems to be comparable.
To define the adaptivity type of a vehicle system, the taxonomy is applied to the required data and
data processing, as shown in Clause 5. More than one type can be applied to one vehicle system and its
components, and combinations of types are possible.
5 Classification of the type of adaptivity for vehicle systems
5.1 General
Vehicle systems are classified into five types of adaptation ranging from type 0 with no adaptation, to type
4 as the highest type of adaptation. Vehicle systems at higher adaptation types exhibit more advanced data
processing capabilities, including the ability to learn from observing user interactions.
In 5.2 to 5.6, each adaptation type is characterized by a general description, the necessary data and data
processing requirements, and an illustrative data flow accompanied by a conceptual architecture.

Additionally, Annex A contains a decision tree to conveniently classify adaptive vehicle systems into the
appropriate types for all stakeholders and end users.
5.2 Type 0 – no adaptation
5.2.1 General description
As depicted in Figure 2, a type 0 vehicle system utilizes real-time user input via various modalities, such
as speech, touch, or gesture, to execute commands initiated by the user, triggering predefined real-time
output on the predefined device accordingly. The system operates on explicit user actions for activating
or deactivating specific functions via their chosen input modality. Importantly, at this type, no data or
configurations are stored—neither functions nor settings are retained.
This type defines a vehicle system with no adaptation, necessitating users to explicitly activate or deactivate
each function individually. This system behaviour applies universally to all users.

a
Data flow can be onboard and/or online.
Figure 2 — Conceptual data flow of type 0 - no adaptation
5.2.2 Example
The user presses the button "relax mode" (real-time input). The vehicle system processes this input as the
predefined command to initiate the "relax mode" (real-time data processing), and the "relax mode" begins
(real-time output).
5.3 Type 1 – saved adaptation
5.3.1 General description
As illustrated in Figure 3, type 1 defines an adaptable vehicle system that allows users to manually save
one or more individual settings or preferences for specific functions. Activation of these previously saved
preferences can occur by user identification which can either be manually by the user, upon the user's
registration within the vehicle, or automatically by the vehicle system when the vehicle recognizes the user,
e.g. via a personalized key or Bluetooth profile from the user's telephone. Additionally, activation can occur
by user input without concrete user identification to save and retrieve settings, such as pressing a button for
a seat memory function that relies on numbered buttons. The real-time output will be displayed or executed
as previously saved by the user.
It is essential to emphasize that the range of possible adaptations, along with their respective setting options,
is predetermined by the development team and cannot be altered by the user.

a
Data flow can be onboard and/or online.
b
Optional and not required.
Figure 3 — Conceptual data flow of type 1 - saved adaptation
5.3.2 Example
A user saves the "relax mode" as the default setting, and the adaptive vehicle system stores this personal
preference, associating it with the user's specific profile (static stored data). The activation of this function
“relax mode” takes place in real-time (real-time output) when the user enters the vehicle (real-time input),
and the adaptive vehicle system identifies and activates the user's personalized "relax mode"
...