ISO 34503:2023

Road Vehicles - Test scenarios for automated driving systems - Specification for operational design domain

This document specifies the requirements for the hierarchical taxonomy for specifying operating conditions which enable the definition of an operational design domain (ODD) of an automated driving system (ADS). This document also specifies requirements for the definition format of an ODD using the taxonomy. The ODD comprises specific conditions (which include the static and dynamic attributes) within which an ADS is designed to function. This document is mainly applicable to level 3 and level 4 ADS. An ODD for level 5 ADS is unlimited (i.e. operation is possible everywhere). This document can be used by organizations taking part in developing safety cases for automated vehicles, in particular, for organizations conducting trials, testing and commercial deployment. This document can also be used by manufacturers of level 3/4 ADS to define the ADS’ operating capability. It may also be of interest to insurers, regulators, service providers, national, local and regional governments to enable them to understand possible ADS deployments and capabilities. This document does not cover the basic test procedures for attributes of the ODD. It does not cover the monitoring requirements of the ODD attributes.

Véhicules routiers — Scénarios d'essai pour les systèmes de conduite automatisée — Spécification du domaine de conception opérationnelle

General Information

• Status: Published
• Publication Date: 07-Aug-2023
• ICS: 43.020 - Road vehicles in general
• Technical Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Drafting Committee: ISO/TC 22/SC 33/WG 9 - Test scenarios of automated driving systems
• Current Stage: 6060 - International Standard published
• Start Date: 08-Aug-2023
• Due Date: 02-May-2023
• Completion Date: 08-Aug-2023

Overview

ISO 34503:2023 - "Road Vehicles - Test scenarios for automated driving systems - Specification for operational design domain" - defines a hierarchical taxonomy and a definition format for the Operational Design Domain (ODD) of automated driving systems (ADS). The ODD captures the specific static and dynamic conditions within which an ADS is designed to operate. ISO 34503:2023 is primarily aimed at level 3 and level 4 ADS (level 5 is considered unlimited) and supports consistent, machine- and human-readable ODD definitions to enable safe testing, trials and commercial deployment.

Key topics and requirements

• Hierarchical ODD taxonomy: structured classification of operating conditions to describe location, road types, drivable area, junctions, scenery elements, and zones.
• ODD attributes: inclusion of both static (infrastructure, signage, road geometry) and dynamic (weather, illumination, traffic agents, connectivity) attributes.
• Definition format requirements: specifies human readability, inclusion/exclusion/conditional expressions, extensibility, relationships between attributes, objective boundaries, and statement composition.
• Scenery and environmental elements: covers drivable area types, lane specification, junctions (roundabouts/intersections), temporary structures, weather, particulates, illumination and connectivity.
• Dynamic elements & agents: treatment of subject vehicle, traffic agents and their role in scenario creation.
• Implications for scenario-based testing: taxonomy enables efficient scenario creation, parametrization and linking of ODD to test scenarios.
• Scope limits: the standard does not define basic test procedures for ODD attributes or monitoring requirements for ODD attributes.

Applications and users

ISO 34503:2023 is practical for organizations involved in ADS safety, testing and deployment:

• ADS manufacturers and suppliers - define and communicate operating capability for level 3/4 systems.
• Test and trial operators - create consistent, repeatable scenario sets and parametrized test conditions.
• Safety case developers and verification teams - assemble evidence tied to explicit ODD boundaries.
• Regulators, insurers and public authorities - assess deployments, procurements and regional suitability of ADS services.
• Service providers and integrators - plan operations and define service-area limitations based on ODD attributes.

By standardizing ODD taxonomy and definition formats, ISO 34503 helps improve ADS safety communication, supports scenario-based verification and enables clearer regulatory and commercial decision-making.

Related standards

• ISO/SAE PAS 22736 - taxonomy and definitions for driving automation terms
• ISO 34501 - vocabulary for ADS test scenarios
• ISO 34502 - scenario-based safety evaluation framework
• ASAM OpenODD - emerging format standard referenced for ODD definition interoperability

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 34503
First edition
2023-08
Road Vehicles — Test scenarios
for automated driving systems —
Specification for operational design
domain
Véhicules routiers — Scénarios d'essai pour les systèmes de
conduite automatisée — Spécification du domaine de conception
opérationnelle
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 Operational design domain (ODD) and target operational domain (TOD) .3
6 ODD and scenario relationship . .3
7 ODD requirements and application .4
7.1 Abstraction of ODD definition. 4
7.2 Monitoring ODD attributes . 5
7.3 Implication to scenario-based testing . 5
8 ODD taxonomy . 6
8.1 General . 6
8.2 Top level ODD classification . 6
9 Scenery elements . 7
9.1 General . 7
9.2 Zones. 8
9.3 Drivable area . 8
9.3.1 General attributes . 8
9.3.2 Drivable area type . 8
9.3.3 Drivable area geometry . 9
9.3.4 Drivable area lane specification . 10
9.3.5 Drivable area signs . 11
9.3.6 Drivable area edge . 11
9.3.7 Drivable area surface .12
9.4 Junctions . . 13
9.4.1 General .13
9.4.2 Roundabout .13
9.4.3 Intersection . 14
9.5 Basic road structures . 14
9.6 Special structures . 14
9.7 Temporary drivable area structures . 15
10 Environmental conditions .15
10.1 General . 15
10.2 Weather . 15
10.2.1 General .15
10.2.2 Ambient air temperature . 15
10.2.3 Wind . 15
10.2.4 Rainfall . 16
10.2.5 Snowfall . 17
10.3 Particulates . 17
10.4 Illumination . 17
10.5 Connectivity . 18
11 Dynamic elements .19
11.1 Traffic agents . 20
11.2 Subject vehicle . 20
12 ODD definition format .21
12.1 General . 21
iii
12.2 Type of definition mode . 21
12.3 Human readability . 21
12.4 Inclusion, exclusion, and conditional . 22
12.5 Extensibility and expressing relationships between ODD attributes .22
12.6 Objective boundaries . 22
12.7 Statement composition. 23
Annex A (informative) Operational design conditions (ODC): including vehicle internal
aspects to the ODD .24
Annex B (informative) Examples of ODD definition (for various regions) .26
Bibliography .29
iv
Foreword
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,
Vehicle dynamics, chassis components and driving automation systems testing.
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
Introduction
The move towards automated driving systems (ADSs) is being driven by the many potential benefits of
the technology, such as increased safety, reduced traffic congestion, lowered emissions and potentially
increased mobility for those unable to drive. In order to realize these benefits, it is essential that the
ADS technology is introduced safely.
The development of automated vehicle technology has received wide public attention, with countries
worldwide focusing on:
— ensuring that the introduction of ADSs for testing/trialling purposes and for commercial operations
is done safely, securely and legally; and
— building public and consumer trust and acceptance of the technology.
A key aspect of the safe use of automated vehicle technology is defining its capabilities and limitations
and clearly communicating these to the end user, leading to a state of “informed safety”. The first step in
establishing the capability of an ADS is the definition of its operational design domain (ODD). In addition
to safe operation, the ODD definition is also important for conformity with laws and regulations and
compliance with vehicle goals, e.g. mobility and comfort needs.
The ODD represents the operating conditions within which an ADS can perform the dynamic driving
task (DDT) safely during a trip. This document focuses on a taxonomy and format for the ODD definition
for a given ADS to create a common understanding of the ODD.
The ODD taxonomy and definition format specified in this document will enable ADS manufacturers
to specify, implement and communicate minimum safety requirements in their designs, and allow end
users (e.g. insurers, national, local, and regional government), operators and regulators to reference
a minimum set of ODD attributes and performance requirements in their procurements. It will also
enable ADS manufacturers, developers and suppliers of components and subcomponents to define the
operating capability and assemble sets of evidence that will improve confidence in the safety of the
resulting product (such as component specifications) and in the data obtained from test and verification
activities.
While there are a number of different testing, trialling and deployment environments, this document
provides a generic taxonomy for defining each of these environments. For a scenario-based verification
methodology for ADS, a hierarchical taxonomy for ODD definition and a definition format also enables
an efficient scenario creation and scenario parametrisation. Such a definition format standard is in
development – ASAM OpenODD.
vi
INTERNATIONAL STANDARD ISO 34503:2023(E)
Road Vehicles — Test scenarios for automated driving
systems — Specification for operational design domain
1 Scope
This document specifies the requirements for the hierarchical taxonomy for specifying operating
conditions which enable the definition of an operational design domain (ODD) of an automated driving
system (ADS). This document also specifies requirements for the definition format of an ODD using the
taxonomy. The ODD comprises specific conditions (which include the static and dynamic attributes)
within which an ADS is designed to function.
This document is mainly applicable to level 3 and level 4 ADS. An ODD for level 5 ADS is unlimited (i.e.
operation is possible everywhere).
This document can be used by organizations taking part in developing safety cases for automated
vehicles, in particular, for organizations conducting trials, testing and commercial deployment. This
document can also be used by manufacturers of level 3/4 ADS to define the ADS’ operating capability.
It may also be of interest to insurers, regulators, service providers, national, local and regional
governments to enable them to understand possible ADS deployments and capabilities.
This document does not cover the basic test procedures for attributes of the ODD. It does not cover the
monitoring requirements of the ODD attributes.
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/SAE PAS 22736, Taxonomy and definitions for terms related to driving automation systems for on-
road motor vehicles
ISO 34501, Road vehicles — Test scenarios for automated driving systems — Vocabulary
ISO 34502, Road vehicles — Test scenarios for automated driving systems — Scenario based safety
evaluation framework
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/SAE PAS 22736 and ISO 34501
and the following 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
dynamic element
movable object or actor in the ODD within the DDT timeframe
Note 1 to entry: Adapted from Reference [5].
3.2
environmental condition
weather or another atmospheric condition and other conditions of the environment which are not
defined as scenery elements (3.4) (as well as information technology connectivity)
3.3
minimal risk manoeuvre
MRM
tactical or operational manoeuvre triggered and executed by the ADS to achieve the minimal risk
condition (MRC)
3.4
scenery element
non-movable element of the ADS-equipped vehicle’s operating environment
Note 1 to entry: This definition is to be used only in the context of an ODD.
Note 2 to entry: Non-movable element is not restricted to static elements. For example, traffic lights, movable
bridges.
3.5
vulnerable road user
non-protected road user such as motorcyclists, cyclists, pedestrians, horse riders and persons with
disabilities or reduced mobility and orientation
3.6
traffic agent
anyone who uses a road including sidewalk and other adjacent spaces
3.7
target operational domain
TOD
set of operating conditions in which an ADS will be expected to operate, including, but not limited to,
environmental, geographical, and time-of-day restrictions, and/or the requisite presence or absence of
certain traffic or roadway characteristics
Note 1 to entry: While the ODD defines of the operating conditions that an ADS is designed to operate in, the TOD
is the area (describing location) where the ADS will be deployed (expected to operate in). As such a TOD may have
conditions outside the ODD of the ADS. For further clarification, see Clause 5.
3.8
current operational domain
COD
specific set of operating conditions which exists presently in the immediate vicinity of an ADS,
including, but not limited to, environmental, geographical, and time-of-day restrictions, and/or the
requisite presence or absence of certain traffic or roadway characteristics
3.9
operational domain
OD
set of operating conditions, including, but not limited to, environmental, geographical, and time-of-day
restrictions, and/or the requisite presence or absence of certain traffic or roadway characteristics
Note 1 to entry: This set can be used to describe real-world conditions in certain environments, geography,
synthetic conditions for testing, and other various purposes.
4 Abbreviated terms
ADS Automated Driving Systems
ASAM Association for Standardization of Automation and Measuring Systems
AV Automated Vehicle
COD Current Operational Domain
DDT Dynamic Driving Task
MRC Minimal Risk Condition
MRM Minimal Risk Manoeuvre
OD Operational Domain
ODD Operational Design Domain
TOD Target Operational Domain
V2I Vehicle to Infrastructure
5 Operational design domain (ODD) and target operational domain (TOD)
An ODD defines the operating conditions under which an ADS is designed to operate safely. However,
the target operational domain (TOD) defines the real-world conditions that an ADS may experience and
is required to safely operate in. Often, the TOD will be a superset of the ODD properties.
In real world deployment of ADS, the difference between an ODD and TOD highlights the limitations of
the ADS. In all practical cases, an ODD definition will not be exhaustive enough to cover all attributes
or occurrences in a TOD. Therefore, it is important to ensure the boundary between ODD and TOD is
defined objectively and to have design mechanisms in the ADS to execute fallback manoeuvres when
an ODD exit is encountered to ensure safe operation of the ADS in a TOD. Current operational domain
(COD) refers to the real-time operational domain, i.e. real-time real-world conditions that the ADS is
experiencing.
The key difference between ODD and TOD is that ODD expresses a specification of the ADS, whereas
TOD is a description/specification of an environment in which various ADSs will be expected to operate.
In general, one can expect that an ODD of any ADS operating within the TOD, is a superset (i.e. including
all aspects) of the TOD. Another perspective is that the TOD can be viewed as a requirement to be met
by all ADS’s ODD – if these ADS are to operate within the environment described by the TOD.
Depending on the design and requirements for an ADS, the TOD may be a superset of the ODD or the
other way round. If the TOD is a superset of the ODD, it implies appropriate risk mitigation measures
will be required as part of the ADS safety measures.
6 ODD and scenario relationship
As an ODD definition needs to be testable, ODD attributes and the definition of the attributes play a key
role in scenario-based testing. It is important to highlight that ODD and scenarios are two distinct but
related constructs. While ODD describes the operating conditions of the ADS in which it is designed to
operate, a scenario along with parts of the scenery elements and environmental conditions, describe
the behaviour of the traffic participants and may also define the desired behaviour of the ego vehicle in
an instantiation (part) of an ODD or outside of an ODD.
NOTE See Annex A for the overall ADS-constraining factors apart from the ODD.
The ODD definition shall be used as one of the inputs for scenario-based safety evaluation framework
in accordance with ISO 34502. Therefore, one of the first steps in a verification and validation process
of an ADS would be to analyse the designed ODD of the ADS to create a set of test scenarios. The second
step would involve testing the desired behaviour of the ADS by choosing a set of behaviours from a
behaviour library. The choice of the behaviours may include undesired behaviours to test the ADS’
response. An instantiation of the ODD together with a desired behaviour and the description of the
traffic participants' behaviour according to events and triggers will provide a scenario definition for
the ADS. Such a qualitative scenario can then be further detailed into functional, abstract, logical and
concrete scenarios to create a scenario library (Figure 1).
Furthermore, the ODD definition can be used as criteria for deciding whether individual test scenarios
are inside, outside or at the boundary of an ODD. Such scenarios also enable the test for activation
and deactivation of the ADS depending on ODD. It is important to test against scenarios outside the
ODD in order to ensure that the ADS is not misused in situations for which it is not designed. Also, a
comparison between a test scenario set and the ODD definition shall be performed to analyse the test
space coverage.
As a centralised scenario library will potentially have a large number of scenarios for different
[4]
ODDs, ODD attributes (see Clause 8) and behaviour labels (ASAM OpenLabel ) can play a key role
in enabling an efficient scenario search for an ADS. Every scenario will have a relationship with an
ODD. In ISO 34502, three types of scenarios are mentioned: perception-, traffic- and vehicle control.
For example, a perception related scenario focused on blind spot detections may exist on a motorway
or on a road in a city centre, where motorway and city centre roads are ODD instantiations. Compared
to an ODD definition, a scenario has additional constructs like events, triggers and other dynamically
[4]
changing behaviours. Such scenario attributes may be classified according to ASAM OpenLabel .
Figure 1 — An example relationship between ODD, behaviour and scenarios
7 ODD requirements and application
7.1 Abstraction of ODD definition
Based on the taxonomy and definition format in this document (Clauses 8-12), an ODD definition shall
be developed by an ADS developer and before deployment should be compared with the stakeholders’
requirements of the operational domain (OD), either individually or in consultation, for the safe
operation of the ADS in the operational domain.
An ODD can be defined from the perspective of an end user or a system specifier. Depending on the
perspective, the abstraction of the ODD definition can vary.
Although the end user and specifier can have different abstractions of ODD, the ODD definition should
be done objectively to avoid any misunderstandings.
Stakeholders or end users may include, but are not limited to, local authorities, regulators, ADS
system users, service providers, manufacturers, developers of an ADS or suppliers of components and
subcomponents. A city council, for example, can develop an ODD definition as part of a procurement
specification for an ADS mobility service, while a manufacturer can develop an ODD definition in order
to convey the ADS’ capabilities and limitations and create the corresponding safety case. Different
stakeholders can develop their ODD definition with varied level of detail.
The abstraction hierarchy to be used for the ODD definition, see Clauses 8 to 11, shall be at the discretion
of the stakeholder. Irrespective of the abstraction level chosen, stakeholders shall specify the ODD
attributes used to inform the scenario-based testing of the ADS.
A stakeholder who defines an ODD by choosing an attribute at a higher abstraction level shall ensure
that all the predefined subattributes are also within the ODD definition, even if they have not been
explicitly mentioned in the ODD definition. In case it is necessary for a specific defined system to have a
detailed ODD, the ODD definition shall be described with a greater level of detail. For example, if an ADS
is designed to be able to handle light rain only (<2,5 mm/h) and is not able to operate in higher intensity
of rainfall, the defined ODD should be specified at this granularity (i.e. with additional subattributes).
The ODD attributes shall be extensible in a way that allows new attributes or subattributes to be added
as a result of stakeholder consultation and ensuring consistency with the existing attributes.
7.2 Monitoring ODD attributes
While performing the DDT, ADS will perceive the operating environment, i.e. will be aware of the near
real-time ODD attributes’ values, so that the ADS can compare the external conditions (i.e. the COD)
with the defined ODD. This is essential for the ADS to be able to decide on triggering the minimal risk
manoeuvre (MRM) or issuing a transition demand by the ADS. During trials, the monitoring of the ODD
attributes may be performed by the safety operator or dispatcher.
ODD attributes may have interdependence and their relationship shall be defined in a prescribed format
(Clause 12). For example, an ADS may have a maximum allowable speed of 70 km/h in the absence of
rainfall, and a reduced maximum allowable speed of 40 km/h in the presence of rainfall. The ADS or the
dispatcher shall be able to compare the defined ODD with the COD. The dispatcher or the ADS need to
decide, for example, to reduce the maximum allowable speed when it is raining as compared to sunny
conditions in order to ensure operation within ODD boundaries.
Defining an ODD boundary is up to the manufacturers’ discretion and may involve subattributes or
qualifiers, such as temporal elements. For example, an ODD boundary may be defined as up to 2 min
of heavy rainfall by adding a relevant subattribute. ODD attributes shall be defined in such a way to
allow the ADS to be aware if it remains within the designed and defined ODD attribute definition. The
ODD monitoring is needed for forecasting an upcoming ODD boundary with sufficient time buffer. In
case of an imminent ODD exit, the ADS should be designed to trigger a transition to a minimal risk
condition (MRC) or issue a transition demand to the fall-back ready user or change the operating mode
to a degraded mode, i.e. lower performance capability mode.
While the role of the human driver/dispatcher is not part of the ODD definition, the ODD is to be defined
in a way that it is understandable to the user (driver/dispatcher) to enable them to take into account the
ODD limits for the safe use of the ADS feature (see Clause 12).
7.3 Implication to scenario-based testing
As part of the ADS development cycle, the ODD definition may be an iterative process with a gradual
increase or decrease in ODD attributes and attribute value coverage. An ODD definition is an essential
work product contributing to the safety case of an ADS. As part of the scenario-based testing process
of an ADS as defined in ISO 34502, constraints given by the ODD definition shall be used to define test
scenarios. As part of the process to show compliance with the defined ODD, test procedures shall be
demonstrated for the specific defined ODD attributes. Testing should cover correct ADS operation
within the ODD, across ODD boundary and responses outside ODD boundary (e.g. reject attempts to
engage outside ODD).
8 ODD taxonomy
8.1 General
ODD attributes (and their subattributes) are specified below in 8.2 and Clauses 9 to 11. If they do not
adequately represent a specific operating environment, stakeholders may extend them, including the
introduction of relevant measurement units (which might reflect temporal or other aspects). While the
taxonomy is extensible, any extensions to the taxonomy which conflict with attributes specified shall
be avoided. Furthermore, while extending the attributes, stakeholders shall ensure that the additional
attributes are placed at the correct hierarchy and group in the taxonomy while providing justification
for the same. For all attributes, the specifier shall provide the objective measurement for the attribute.
In case any of the attributes are not relevant for the operating condition of the ADS, such attributes may
be ignored from the ODD definition (depending on the format definition, see Clause 12). Stakeholders
may add additional layers of attributes between parent and child attributes in order to aid grouping of
the attributes.
NOTE For examples of ODD descriptions from different use cases, see Annex B.
8.2 Top level ODD classification
At the top level, the ODD shall be classified into the following attributes:
— scenery elements;
— environmental conditions;
— dynamic elements.
The “scenery elements” attribute (in the context of defining an ODD) shall consist of the spatially fixed
elements of the operating environment (e.g. roads, traffic lights, etc.), relative to the ego vehicle (in
terms of position of the elements).
The “environmental conditions” attribute shall consist of weather and atmospheric conditions
(including information technology connectivity).
The “dynamic elements” attribute shall consist of the movable elements of the ODD, e.g. traffic, subject
vehicle.
Figure 2 illustrates a top-level taxonomy of the ODD attributes. All attributes are considered to have
equal importance.
While scenery elements ODD attributes (Clause 9) consist of spatially fixed objects, flow of traffic may
change with time on or around scenery elements attributes. For example, traffic flow direction on some
roads (drivable area) may change with time of the day or day of the week. Similarly, some bridges may
close and open to let boats and ships to pass. While the state of the bridge changes, the location of the
bridge itself does not change. Therefore, all attributes with fixed location are considered to be part of
scenery elements attributes, while their state may change with time.
Environmental conditions (Clause 10) play an important role in influencing the safe operation of ADS-
equipped vehicles. The environmental conditions have the potential to impact all ADS functions from
perception and planning to actuation control, as they can impact visibility, sensor fidelity, vehicle
manoeuvrability due to changing drivable area surface conditions, and communication systems.
Figure 2 — Top level taxonomy with ODD attributes
Similarly, dynamic elements (Clause 11) add complexity to the operating environments due to their
diverse nature, and their predictable and unpredictable behaviour.
Annex B provides examples of ODD definitions using the ODD taxonomy and format specified in
Clauses 8 to 11 and Clause 12 respectively.
9 Scenery elements
9.1 General
At the top level, “scenery elements” shall at least be classified into the following attributes or have
additional attributes:
a) zones;
b) drivable area;
c) junctions;
d) special structures;
e) basic road structures;
f) temporary drivable structures.
9.2 Zones
Zones include special road configurations which may differ from typical conditions for driving, or areas
with specific driving regulations or environmental conditions. Some ADS applications may be restricted
to specific zones where the ADS can operate safely. Zones attributes should at least be classified into
the following attributes:
a) geo-fenced areas;
b) zone type:
1) fixed zone: school zone, environmental zone, industrial zone, parking lot;
2) dynamic zone: traffic management zone, mobile work zone, ;
3) interference zone: urban canyon, overhead wires, dense foliage;
4) port zone;
5) freight distribution centre;
c) regions or states.
By defining a geo-fenced zone, one may already imply some of the other attributes in 9.3 to Clause 11.
However, it may be possible that the entire geo-fenced zone is excluded from the ODD definition, and
any exceptions shall be defined using the taxonomy and the format defined in this document.
In case a zone is defined as an ODD attribute, it shall imply that everything inside the zone is a part of
the ODD unless explicitly excluded.
9.3 Drivable area
9.3.1 General attributes
A drivable area refers to the area on which the ADS equipped vehicle may operate. Drivable area should
at least be classified into the following attributes:
a) drivable area type;
b) drivable area geometry;
c) drivable area lane specification;
d) drivable area signs;
e) drivable area edge;
f) drivable area surface.
9.3.2 Drivable area type
A drivable area type should at least be classified into the following attributes:
a) motorways or highways or interstates;
b) primary roads (e.g. dual-carriage ways, single carriage ways);
c) radial roads;
d) distributor roads;
e) minor or local roads;
f) slip roads or off-ramps;
g) parking space;
h) shared space.
Motorways or highways or interstates are high-traffic roads where non-motorized vehicles and
pedestrians are prohibited.
Radial roads are high density traffic roads which connect the motorways to distributor roads or urban
centres.
Distributor roads connect radial roads with minor or local roads and generally have low to moderate
capacity.
Minor roads or local roads provide access to residential areas and other local developments. These
roads carry low volumes of traffic.
A slip road is a road which is used to drive on to and off a motorway or highways or interstates.
A parking space is the physical space where one vehicle is parked.
A shared space may be shared between subject vehicle and other actors, for example, pedestrians or
cyclists.
When stakeholders use the above attributes for driveable area type, stakeholders shall define each of
the attributes used as part of the ODD definition. It may be possible that in certain regions the above
attributes are given vernacular names. In such cases, stakeholders shall define each term to enable
mapping to the above attributes.
Each of the drivable area types should at least be further classified into those:
1) with active traffic management; and
2) without active traffic management.
Each of the drivable area types should have associated speed limit(s).
9.3.3 Drivable area geometry
A drivable area geometry should be described by viewing the drivable area layout in three planes:
a) horizontal plane;
b) transverse plane;
c) longitudinal plane.
In case any of the attributes are not relevant for the operating condition of the ADS, such attributes may
be ignored from the ODD definition (depending on the format definition, see Clause 12).
In a horizontal plane, two main attributes should be included:
1) straight lines; and
2) curves.
Curves should be measured by the radius of curvature of the road. Horizontal alignment can be seen
when the road layout is projected on a horizontal plane.
In a transverse plane, the main attributes should at least be classified into the following attributes or
have additional attributes:
i) type: divided, undivided, pavement
ii) barriers on road edges;
v) types of lanes together;
vi) superelevation / banking.
A cross section plane is the road configuration in the transverse profile. The cross section below (see
Figure 3) provides information about the features on or adjacent to the road, e.g. pavement or divided
drivable area. Transverse plane attributes may include banking and camber.
In a longitudinal plane, three main attributes should be included:
1. up-slope (positive gradient);
2. down-slope (negative-gradient);
3. level plane.
Longitudinal alignment can be seen in a vertical configuration of the road in a longitudinal section.
Figure 3 — Road geometry configurations
9.3.4 Drivable area lane specification
A drivable area lane is the drivable area that a vehicle would be expected to travel along in the
absence of any obstruction without the driver’s or ADS’ desire to change the path of travel (adapted
from ISO 11270). The drivable area lane specification should at least be classified into the following
attributes:
a) lane dimensions;
b) lane marking;
c) lane type;
d) direction of travel;
e) speed limit;
f) lane usage.
A drivable area lane type should include bus lane, traffic lane, cycle lane, tram lane, emergency lane,
shared lane or other special purpose lanes.
Drivable area lane markings are delineators intentionally placed on the borderline of the lane (adapted
from ISO 11270). Drivable area lane marking may include clear lane marking, blurred lane marking, no
lane marking and temporary lane marking.
Direction of travel should include right hand and left-hand travel.
9.3.5 Drivable area signs
Drivable area signs should at least be classified into the following attributes:
a) sign type: regulatory signs (e.g. traffic lights), warning signs, information signs;
b) sign feature: movable signs, fixed signs.
Regulatory signs are used to indicate or reinforce traffic laws, regulations or requirements. They are
intended to instruct drivable area users on what they must or should do (or not do) under a given set of
circumstances.
Warning signs provide advance notice of hazardous situations or conditions on the drivable surface.
These are advisory signs.
Information signs provide directions and information about services which may be of interest to the
driver, or the ADS equipped vehicle.
Each of the above drivable area signs should be further classified into variable or uniform messaging.
For example, smart highways or motorways may change their speed limits depending on external
factors.
Additionally, each of the attributes should be classified by their operation duration into full-time or
temporary (e.g. due to road construction or road incidents).
Each of the attributes may also be classified based on the language used in the sign in case textual
information is displayed on the sign.
Quality of signs may be defined by the stakeholders.
9.3.6 Drivable area edge
A drivable area edge is the outermost edge of the drivable area in which a vehicle travels. The drivable
area edge should at least be classified into the following attributes:
a) line markers;
b) shoulder:
1) paved or gravel;
2) grass;
c) snowbanks;
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