ISO 26684:2015

INTERNATIONAL ISO
STANDARD 26684
First edition
2015-05-01
Intelligent transport systems (ITS) —
Cooperative intersection signal
information and violation warning
systems (CIWS) — Performance
requirements and test procedures
Systèmes intelligents de transport (ITS) — Systèmes d’avertissement
d’information et de violation du signal d’intersection coopérative
(CIWS) — Exigences de performance et modes opératoires d’essai
Reference number
©
ISO 2015
© ISO 2015
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Classification . 3
5.1 System configuration . 3
5.2 System configuration . 3
6 Functional requirements . 4
6.1 CIWS state diagram . 4
6.1.1 CIWS states . 5
6.2 Transition criteria . 5
6.2.1 Criterion (1): RSE activation . 5
6.2.2 Criterion (2): RSE deactivation . 6
6.2.3 Criterion (3): OBE activation . 6
6.2.4 Criterion (4): OBE deactivation . 6
6.2.5 Class II criterion (5): Warning activation . 6
6.2.6 Class II criterion (6): Warning deactivation . 6
6.3 Functional requirements of OBE . 6
6.3.1 Acquisition of travel direction . 6
6.3.2 Acquisition of vehicle position . 6
6.3.3 Acquisition of vehicle speed. 6
6.3.4 Identification of traffic signal information . 6
6.3.5 Judgement of warning necessity and warning contents (Class II) . . 6
6.3.6 Timing of warning output . 7
6.3.7 Timing of warning termination . 7
6.3.8 HMI display contents. 7
6.4 Functional requirements of RSE . 7
6.4.1 Data sets . 7
6.4.2 Communication range . 7
6.4.3 Communication delay . 7
6.5 CIWS system performance . 7
6.5.1 System capabilities . . 7
6.5.2 Provision of information . 8
6.5.3 Warning threshold for signal violation . 8
7 Test requirements . 9
7.1 Test vehicle . 9
7.2 Test site . 9
7.2.1 Environmental conditions . 9
7.2.2 Geometric conditions .10
7.2.3 RSE location for the systems providing communication only at X .10
AL
7.3 Test procedure .10
7.3.1 Test method .10
Bibliography .12
Foreword
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The committee responsible for this document is ISO/TC 204, Intelligent transport systems.
iv © ISO 2015 – All rights reserved

Introduction
The main system function of cooperative intersection signal information and violation warning
systems (CIWS) is to warn drivers who are about to violate an intersection’s traffic signal to stop at the
prescribed location. The CIWS is intended to provide a cooperative vehicle and infrastructure system
that reduces the likelihood and severity of crashes at signalized intersections by providing the signal
phase information and/or by warning the driver that an intersection signal violation is about to occur.
The system uses information communicated from the roadside infrastructure to determine if a warning
should be given to a driver.
The purpose of implementing CIWS is to reduce violations of traffic signals at signalized intersections to:
(a) reduce fatalities, (b) reduce the number and/or severity of injuries, and (c) reduce property damage
associated with collisions.
This International Standard addresses CIWS for use in road vehicles approaching signalized intersections.
This International Standard may be used as a system level standard by other standards, which extend
the CIWS to a more detailed standard utilizing wireless communication technologies. Issues such as the
specific requirements for the function and performance of communication technology or traffic control
facilities (including traffic signal controllers) will not be considered in this International Standard.
INTERNATIONAL STANDARD ISO 26684:2015(E)
Intelligent transport systems (ITS) — Cooperative
intersection signal information and violation warning
systems (CIWS) — Performance requirements and test
procedures
1 Scope
This International Standard specifies the concept of operation, system requirements, and test methods
for cooperative intersection signal information and violation warning systems (CIWS) at signalized
intersections. CIWS are intended to reduce the likelihood of crash injury, damage, and fatality by
enhancing the capability of drivers to avoid crash situations at signalized intersections.
The scope of CIWS standardization includes basic functions, functional requirements, performance
requirements, information contents, and test methods.
The characteristics of the technologies used to communicate between the signal controller and
the vehicles are not addressed by this International Standard nor are the behavioural responses by
drivers, the various capabilities of vehicles on the road, or the multitude of combinations of these two
characteristics.
2 Normative references
There are no normative references cited in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
stopping distance
distance, X travelled by a vehicle with the speed of v, from the time the driver receives CIWS warning
v,
until the vehicle comes to a complete stop
Note 1 to entry: This includes the distance travelled during the driver perception and reaction time.
3.2
speed of vehicle
speed of the subject vehicle, v
3.3
time to arrive at stop line of intersection
TTAI
time needed for a vehicle approaching the intersection at a
...