ISO 21734-1:2022

INTERNATIONAL ISO
STANDARD 21734-1
First edition
2022-11
Intelligent transport systems —
Performance testing for connectivity
and safety functions of automated
driving buses in public transport —
Part 1:
General framework
Systèmes de transport intelligents - Essais de performance pour
les fonctions de connectivité et de sécurité des bus à conduite
automatisée dans les transports publics —
Partie 1: Cadre général
Reference number
ISO 21734-1:2022(E)
© ISO 2022

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ISO 21734-1:2022(E)
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© ISO 2022
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ISO 21734-1:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 5
4 General information . 5
4.1 ISO 21734 series overview and structure . 5
4.2 Purpose of the ISO 21734 series . 6
5 ADB system Components . 6
5.1 Overview . 6
5.2 ADB component . 6
5.3 MC centre component . 7
5.4 IoT infrastructure component . 7
5.5 Smart bus station component . 7
5.6 ADB user component . 7
6 ADB system framework . 8
6.1 Overview . 8
6.2 Safety aspect of ADB system framework . 8
6.2.1 General . 8
6.2.2 Road infrastructure . 8
6.2.3 Safety performance test elements of the ADB operation . 9
6.3 Connectivity aspect of the ADB system framework . 10
6.3.1 General . 10
6.3.2 Connectivity infrastructure . 10
6.3.3 Connectivity performance test elements of ADB operation . 11
6.4 ADB system framework requirements .12
6.4.1 ADB component requirements.12
6.4.2 MC centre component requirements . 13
6.4.3 IoT infrastructure requirements . 16
6.4.4 Smart bus station requirements . 16
6.4.5 ADB user requirements . 17
6.5 ADB service framework . 18
7 Required data sets .19
7.1 General . 19
7.2 Operation . 20
7.2.1 Signalized intersection case . . 20
7.2.2 Crosswalk case . 21
7.2.3 Bus stop case. 22
7.3 ADB service . 23
8 Use cases .25
8.1 General . 25
8.2 Left turn on intersection .25
8.2.1 Use case 1-1: Protected left turn on intersection . 25
8.2.2 Use case 1-2: Permitted left turn on intersection . 26
8.3 Straight forward on intersection . 27
8.3.1 Use case 2: Straight forward on intersection. 27
8.4 Right turn on intersection . .28
8.4.1 Use case 3-1: Right turn on intersection .28
8.4.2 Use case 3-2: Right turn on red on intersection .29
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ISO 21734-1:2022(E)
8.5 Crosswalk . 30
8.5.1 Use case 4-1: Signalized pedestrian crosswalk .30
8.5.2 Use case 4-2: Non-signalized pedestrian crosswalk . 31
8.6 Smart bus station . 32
8.6.1 Use case 5-1: Bus station with bay . 32
8.6.2 Use case 5-2: Bus station without bay . 33
Bibliography .35
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ISO 21734-1:2022(E)
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
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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
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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.
A list of all parts in the ISO 21734 series can be found on the ISO website.
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.
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ISO 21734-1:2022(E)
Introduction
Automated vehicle technology has been developing rapidly in recent years as one of the measures for
reducing automobile accidents caused by human errors and for promoting the automobile industry.
The automated driving bus (ADB) is a new type of public transport mode embedded with automated
vehicle technologies. The progress of the development and deployment of the ADB has been accelerated
in recent years, exceeding the speed of automated passenger vehicles.
The overall purpose of this document is to provide technical standards at the international level to
ensure the safety and connectivity of the ADB operating as a public transport mode. The objectives of
this document include building a framework for operating ADBs in public transit networks, developing
performance test methods and procedures in terms of safety and connectivity of ADBs that require
communication with roadside infrastructure and with the monitoring and control centre, and providing
the service framework and use cases as references for field applications.
From the connectivity perspective, the ADB needs to be connected with traffic signal networks for
vehicles and pedestrians, with the monitoring and control centre for bus operation, and with other
relevant infrastructure to ensure its effectiveness as a public transport mode. In terms of safety, the
ADB needs to be embedded with automated vehicle functions to connect with the wireless signal
control system and to be ready to respond to unexpected situations involving other road users such as
pedestrians and bicyclists.
Furthermore, the authorities of public transport need technical standards to measure the performance
of ADB for enhancing public safety on roads.
Therefore, this document is intended to benefit public transport operators, relevant governing
authorities of public transport, and industrial stakeholders.
This document provides the basis for the development of performance testing for connectivity and
safety functions of ADB on a national and international level.
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INTERNATIONAL STANDARD ISO 21734-1:2022(E)
Intelligent transport systems — Performance testing for
connectivity and safety functions of automated driving
buses in public transport —
Part 1:
General framework
1 Scope
This document specifies the general framework and the automated driving bus (ADB) system
components for operating ADBs in public transport networks, including:
a) the general framework and the operation scheme for public transport systems in cooperation with
ADBs;
b) definitions of system components for operating ADBs; and
c) definitions of functions and requirements of each system component for providing transport
services with ADBs.
This document is applicable to bodies in public transport systems and services including transportation
operators, public transport governing authorities and relevant industries.
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 Terms and definitions
3.1.1
automated driving bus
ADB
bus designed for public transport and embedded with automated driving functions based on SAE level
4 or higher
3.1.2
operation safety
set of minimum safety requirements ensuring an automated driving bus's expected functions as a
public transport mode when operating in cooperation with road infrastructure
Note 1 to entry: Road infrastructure includes exclusive bus lanes, bus stations, signalized and non-signalized
intersections, crosswalks for pedestrians and bicyclists, general traffic signals, bus priority signals, and
monitoring and control centres.
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ISO 21734-1:2022(E)
3.1.3
safety function
set of minimum functions related to the safety of an automated driving bus (ADB) as a public transport
mode, facilitating passengers on board, at bus stations and responding to emergency events that can
arise both inside and outside of ADBs
3.1.4
connectivity of ADB
connectivity performance of an automated driving bus (ADB) system that ensures the stable and
reliable provision of the information feed required to provide safe public transport services
3.1.5
transport information
set of information required for automated driving buses (ADBs) to function as a public mode
Note 1 to entry: This includes operation information exchanged between road infrastructure and ADBs
themselves, bus priority signal information, passengers’ boarding and alighting information, roadside signage
equipment information, battery charge and discharge information (if the bus is an electric bus), etc.
3.1.6
ADB system framework
framework for ensuring stability and safety of automated driving bus system operations through
interactions among automated driving bus (ADB) system components
3.1.7
ADB system components
required components for operating an automated driving bus (ADB) system
Note 1 to entry: The components include the ADB, the monitoring and control centre, Internet of Things
infrastructure, smart bus stations and users.
3.1.8
ADB service framework
framework for transport services provided by the automated driving bus (ADB) system through
interactions among the ADB service components, consisting of the ADB, the monitoring and control
centre, passengers, smart bus stations and Internet of Things infrastructure
3.1.9
monitoring and control centre
MC centre
system that ensures the safe operation of the automated driving bus (ADB) system by monitoring
and controlling the fleet through collecting data from each component (the ADB, ADB users, Internet
of Things infrastructure, smart bus stations), processing the data, and providing comprehensive
information to each component
3.1.10
IoT infrastructure
Internet of Things infrastructure
sensor system collecting road traffic and environment data at intersections, pedestrian crosswalks and
smart bus stations
Note 1 to entry: The collected data is transmitted to the monitoring and control centre and automated driving
buses (ADBs) directly through communication networks.
3.1.11
smart bus station
facility where an automated driving bus stops and passengers safely board, alight, and wait for an
automated driving bus
Note 1 to entry: The smart bus station is installed with a station kiosk and Internet of Things infrastructure to
communicate with the monitoring and control centre.
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ISO 21734-1:2022(E)
3.1.12
station kiosk
device that is installed at a smart bus station and assists passengers with their boarding reservations,
the payments and ticketing
3.1.13
pickup station
smart bus station which is designated by the monitoring and control centre and at which it is intended
that an automated driving bus (ADB) will pick up passengers when operating a demand-responsive
route
3.1.14
routine station
fixed smart bus station that is designated for automated driving buses (ADBs) as a location to stop at
for picking up and dropping off passengers
3.1.15
one-time boarding ticket
boarding ticket that is used for one round trip
Note 1 to entry: Depending on reservation methods, tickets can be either paper or electronic.
3.1.16
ADB users
general passengers who are the primary party receiving mobility services and legal entities providing
mobility services to the passengers including local authorities and private bus operators
3.1.17
passenger
one of the automated driving bus (ADB) users receiving ADB mobility services
3.1.18
operator
one of the users who is responsible for operating and managing the automated driving bus (ADB)
systems
3.1.19
operation manager
person responsible for monitoring the automated driving bus (ADB) fleet operation and responding to
emergencies in the monitoring and control centre
3.1.20
in-vehicle operation manager
person responsible for monitoring automated driving bus operations and responding to emergencies in
an automated driving bus (ADB) vehicle
3.1.21
on-demand route
operating measure with flexible schedule and route to respond to passengers’ demands within the
delineated service area
Note 1 to entry: Passengers may only board and alight at a smart bus station.
Note 2 to entry: An automated driving bus (ADB) can deviate from a fixed route to an on-demand route in
response to the passengers’ demand. However, the automated driving bus should stop at a smart bus station.
3.1.22
automated driving message
ADM
message carrying data collected by a suite of automated driving bus (ADB) sensors
Note 1 to entry: The types of messages and the data each message includes are as follows:
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ISO 21734-1:2022(E)
— ADB driving messages include speed, acceleration and deceleration, angular acceleration, etc.
— ADB positioning messages include latitude, longitude, global navigation satellite system mode, etc.
— Route messages include a route ID, stopovers, the destination, etc.
— Route following messages include orientation control, control speed, acceleration, brake, mission, etc.
— Object messages include object type, distance to object, etc.
— Decision messages include system decision messages such as departure, stop, waiting, transmission
information, etc.
— Sensor messages include fail or safe, rerun message, etc.
— Automated driving status messages include fail or safe, passenger information, etc.
3.1.23
automated driving service message
ASM
service message such as automated driving control, road driving and pedestrian protection, and the
collected information which includes service unique ID, service purpose and service provision location,
etc.
3.1.24
basic safety message
BSM
message providing basic information for safe driving such as communication status, weather
information, system status, etc.
3.1.25
emergency event message
EEM
message providing information for responding to the vehicle emergency and driving requirements
when operating
Note 1 to entry: The collected information includes emergency event ID, location, time of the emergency, etc.
3.1.26
routine data set
data set that the two components (automated driving bus and monitoring and control centre) regularly
exchange without a request from each side
3.1.27
event data set
data set provided when requested by automated driving buses (ADBs) or the monitoring and control
centre
3.1.28
backup data set
data sets stored once the automated driving buses (ADBs) finish one round of the route
3.1.29
target location
specific point on an automated driving bus route where an automated driving bus is aiming to move on
3.1.30
target vehicle
vehicle that can form a conflict with an automated driving bus by driving in opposite directions or
merging into the same lane, at the same location, and at the same time
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ISO 21734-1:2022(E)
3.1.31
target object
pedestrian, bicycle rider and other non-human object that can potentially form a conflict with an
automated driving bus (ADB)
3.2 Abbreviated terms
BIS bus information system
BMS bus management system
BRT bus rapid transit
DSRC dedicated short range communication
GNSS global navigation satellite system
IoT Internet of Things
LTE long term evolution
RSE roadside equipment
RSU roadside unit
SOH state of health for electric vehicle battery
TOD transport-oriented development
V2I vehicle to infrastructure
V2X vehicle to everything
WAVE wireless access for vehicle environment
4 General information
4.1 ISO 21734 series overview and structure
The ISO 21734 series specifies documents and standards related to the connectivity and safety
functions required to support the implementation of the ADB system in the public transport network.
Unlike autonomous driving vehicles which make operation manoeuvres based on their own sensor
data, ADBs are connected with the MC centre and Internet of Things (IoT) infrastructure for obtaining
information that is critical for ensuring safety but undetectable by their own sensors.
This document (ISO 21734-1) defines five components of the ADB system that are required for safe
operations, the objectives and scopes of performance tests in terms of connectivity and safety for ADB
operations, and service framework and use cases.
1)
ISO 21734-2:— specifies the performance requirements and test procedures for ADBs to operate
in existing public transport systems. It specifies appropriate types of test methods and performance
standards to ensure the overall safety of public transport operations.
2)
ISO/TR 21734-3:— specifies the service framework and uses cases as a technical reference for
field applications. The service framework is composed of software that utilizes components of ADBs,
1) Under preparation. Stage at the time of publication: ISO/AWI 21734-2:2022.
2) Under preparation. Stage at the time of publication ISO/DTR 21734-3:2022.
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ISO 21734-1:2022(E)
passengers, IoT infrastructure, smart bus stations, the MC centre and other elements for serving
passengers.
4.2 Purpose of the ISO 21734 series
The overall purpose of ISO 21734 series is to set performance standards, testing methods and
procedures for operating ADBs when adopted for a conventional bus system.
The purpose of ISO 21734–1 (this document) is to provide general information on the ISO 21734 series,
including the basic structure of the series. It further specifies five ADB system components that are
required for ADBs to operate in existing bus system and use cases.
The purpose of ISO 21734-2 is to specify performance requirements to be adopted safely as an ADB
system in terms of safety and connectivity and to specify test procedures for ensuring safety and
connectivity of the ADB system operation.
The purpose of ISO 21734-3 is to specify the ADB system service framework and use cases as a reference
for application.
5 ADB system Components
5.1 Overview
The ADB system shall consist of five components as shown in Figure 1: ADBs, the MC centre, IoT
Infrastructure, smart bus stations and ADB users.
Figure 1 — Five components of ADB system
5.2 ADB component
The ADB component is the most important component; all others except ADB user are supporting the
safe driving of ADBs. An ADB vehicle shall be designed for carriage of passengers with capacity of more
than nine persons and shall be embedded with level 4 automated vehicle technologies or higher based
on SAE J3016.
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ISO 21734-1:2022(E)
The ADB shall be capable of operating on fixed and on-demand routes, communicating with the
MC centre and IoT infrastructure, detecting traffic signals and other objects that may deter its safe
operation, allowing passengers to board and alight at a smart bus station regardle
...