ISO/TS 19091:2019

TECHNICAL ISO/TS
SPECIFICATION 19091
Second edition
2019-06
Intelligent transport systems —
Cooperative ITS — Using V2I and I2V
communications for applications
related to signalized intersections
Systèmes intelligents de transport — Coopérative ITS — Utilisation
de communications V2I et I2V pour des applications relatives aux
intersections signalées
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

ISO TS 19091:2019 (E)
Contents Page
Foreword . vi
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 10
5 General description (informative). 12
5.1 Overview . 12
5.2 Functional model . 12
5.2.1 Description . 12
5.2.2 Architecture . 14
5.2.3 Message interactions . 16
5.2.4 Common operational assumptions . 16
5.3 Safety use cases . 18
5.3.1 Intent . 18
5.3.2 Additional assumptions . 18
5.3.3 Architecture implications . 18
5.4 Mobility/sustainability use cases . 19
5.4.1 Intent . 19
5.4.2 Additional assumptions . 19
5.4.3 Architecture implications . 19
5.5 Priority/pre-emption use cases . 20
5.5.1 Intent . 20
5.5.2 Additional assumptions . 21
5.5.3 Architecture implications . 21
5.5.4 Public transport signal priority application . 22
5.5.5 Freight vehicle signal priority application . 23
5.5.6 Emergency (public safety) vehicle pre-emption application . 25
6 Function description (informative). 25
6.1 Public safety vehicle . 26
6.1.1 Broadcast public safety vehicle information . 26
6.1.2 Broadcast emergency response indication. 26
6.2 Signal pre-emption . 26
6.2.1 Signal pre-empt request (normal power) . 26
6.2.2 Signal pre-empt request (high power) . 26
6.2.3 Request signal pre-empt — Message identifier . 27
6.2.4 Request signal pre-empt — Intersection identifier . 27
6.2.5 Request signal pre-empt — Approach lane . 27
6.2.6 Request signal pre-empt — Egress lane . 27
6.2.7 Request signal pre-empt — Vehicle class . 27
6.2.8 Request signal pre-empt — Time of service . 27
6.2.9 Request signal pre-empt — Vehicle identity . 28
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ISO TS 19091:2019 (E)
6.2.10 Request signal pre-empt — Vehicle location and speed . 28
6.2.11 Request signal pre-empt — Cancellation . 28
6.2.12 Request signal pre-empt — Transaction identifier . 28
6.2.13 Request signal pre-empt — Duration . 28
6.3 Public transport and commercial vehicle . 28
6.3.1 Broadcast priority requesting vehicle information . 28
6.4 Signal priority requirements . 29
6.4.1 Signal priority request . 29
6.4.2 Request signal priority — Message identifier . 29
6.4.3 Request signal priority — Intersection identifier . 29
6.4.4 Request signal priority — Approach lane . 29
6.4.5 Request signal priority — Egress lane . 29
6.4.6 Request signal priority — Vehicle class . 30
6.4.7 Request signal priority — Time of service . 30
6.4.8 Request signal priority — Vehicle identity . 30
6.4.9 Request signal priority — Vehicle location and speed . 30
6.4.10 Request signal priority — Service information . 30
6.4.11 Request signal priority cancellation . 31
6.4.12 Request signal priority — Priority request level . 31
6.4.13 Request signal priority — Transaction identifier . 31
6.4.14 Request signal priority — Duration . 31
6.4.15 Request signal priority — Transit schedule . 31
6.5 Broadcast area's geometrics. 31
6.5.1 Broadcast roadway geometrics . 31
6.5.2 Broadcast roadway geometrics — Message identifier . 31
6.5.3 Broadcast intersection — Identifier . 32
6.5.4 Broadcast intersection — Reference point . 32
6.5.5 Broadcast intersection — Lane/approach default width . 32
6.5.6 Broadcast intersection — Egress lanes/approach . 32
6.5.7 Broadcast intersection — Ingress lanes/approach . 32
6.5.8 Broadcast intersection — Lane/approach number . 32
6.5.9 Broadcast intersection — Lane/approach centerline coordinates . 32
6.5.10 Broadcast intersection — Vehicle lane/approach manoeuvres . 33
6.5.11 Broadcast intersection — Pedestrian crossing lane/approach manoeuvres . 33
6.5.12 Broadcast intersection — Special lane/approach manoeuvres . 34
6.5.13 Broadcast intersection — Version identifier . 34
6.5.14 Broadcast intersection — Crossings . 34
6.5.15 Broadcast intersection — Lane/approach width . 34
6.5.16 Broadcast intersection — Node lane/approach width . 34
6.5.17 Broadcast intersection — Egress connection . 35
6.5.18 Broadcast intersection — Traffic control . 35
6.5.19 Broadcast intersection — Traffic control by lane/approach . 35
6.5.20 Broadcast road conditions . 35
6.5.21 Broadcast intersection — Signal group . 35
6.6 Broadcast GNSS augmentation details . 35
6.6.1 Broadcast GNSS augmentations . 35
6.6.2 Broadcast GNSS augmentation detail — NMEA . 36
6.6.3 Broadcast GNSS augmentation detail — RTCM . 36
6.7 Signalized intersection requirements . 36
6.7.1 Broadcast signal phase and timing information . 36
6.7.2 Broadcast signal phase and timing — Message identifier . 36
6.7.3 Broadcast signal phase and timing — Intersection identifier . 36
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ISO TS 19091:2019 (E)
6.7.4 Broadcast signal phase and timing — Intersection status . 36
6.7.5 Broadcast signal phase and timing — Timestamp . 37
6.7.6 Broadcast manoeuvre — Signal group . 37
6.7.7 Broadcast manoeuvre — Manoeuvre state . 37
6.7.8 Broadcast manoeuvre — Vehicular state . 37
6.7.9 Broadcast manoeuvre — Pedestrian state. 37
6.7.10 Broadcast manoeuvre — Special state . 37
6.7.11 Broadcast manoeuvre — Time of change — Minimum . 37
6.7.12 Broadcast manoeuvre — Time of change — Maximum . 38
6.7.13 Broadcast manoeuvre — Succeeding signal indications . 38
6.7.14 Broadcast manoeuvre — Succeeding signal indication time of change . 39
6.7.15 Broadcast manoeuvre pending manoeuvre start time. 39
6.7.16 Broadcast manoeuvre — Pedestrian detect . 39
6.7.17 Broadcast manoeuvre — Pedestrian call . 39
6.7.18 Broadcast manoeuvre — Optimal speed information . 39
6.7.19 Broadcast manoeuvre — Signal progression information . 39
6.7.20 Broadcast manoeuvre — Egress lane queue . 39
6.7.21 Broadcast manoeuvre — Egress lane storage availability . 40
6.7.22 Broadcast manoeuvre — Wait indication . 40
6.8 Broadcast cross traffic sensor information . 40
6.9 Broadcast vulnerable road user sensor information . 40
6.10 Broadcast dilemma zone violation warning. 40
6.11 Broadcast signal preferential treatment status . 40
6.11.1 Broadcast preferential treatment — Signal status message . 40
6.11.2 Broadcast preferential treatment — Message identifier . 41
6.11.3 Broadcast preferential treatment — Intersection identifier . 41
6.11.4 Broadcast preferential treatment — Intersection status . 41
6.11.5 Broadcast preferential treatment — Prioritization request status . 41
6.11.6 Broadcast preferential treatment — Vehicle source . 41
6.11.7 Broadcast preferential treatment — Transaction identifier . 41
6.12 Message identifier . 41
6.13 System performance requirements . 42
6.13.1 Broadcast intersection — Computed lane/approach . 42
6.14 Transmission rates — Signal preferential treatment . 42
6.14.1 Maximum transmission rate — Request signal preferential treatment . 42
6.14.2 Maximum response time — Request signal preferential treatment . 42
6.14.3 Minimum transmission rate — Signal status message . 42
6.14.4 Minimum transmission period — Signal status message . 42
6.15 Transmission rate requirements — Broadcast roadway geometrics information . 42
6.15.1 Minimum transmission rate — Broadcast roadway geometrics information . 43
6.15.2 Maximum transmission rate — Broadcast roadway geometrics information . 43
6.15.3 Default transmission rate — Broadcast roadway geometrics information . 43
6.16 Transmission rate requirements — GNSS augmentations detail broadcasts . 43
6.16.1 Minimum transmission rate — GNSS augmentation details broadcasts . 43
6.16.2 Default transmission rate — GNSS augmentation details broadcasts . 43
6.17 Transmission rate requirements — Broadcast signal phase and timing information . 43
6.17.1 Minimum transmission rate — Broadcast signal phase and timing information. 43
6.17.2 Maximum transmission rate — Broadcast signal phase and timing information . 43
6.17.3 Default transmission rate — Broadcast signal phase and timing information . 43
6.18 Transmission rate requirements — Broadcast cross traffic sensor information . 44
6.18.1 Minimum transmission rate — Broadcast cross traffic sensor information . 44
6.18.2 Maximum transmission rate — Broadcast cross traffic sensor information . 44
6.18.3 Default transmission rate — Broadcast cross traffic sensor information . 44
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ISO TS 19091:2019 (E)
6.19 Transmission rate requirements — Broadcast vulnerable road user sensor
information . 44
6.19.1 Transmission rate — Broadcast vulnerable road user sensor information . 44
6.19.2 Maximum transmission rate — Broadcast vulnerable road user sensor information . 44
6.19.3 Default transmission rate — Broadcast vulnerable road user sensor information . 44
7 Messages . 44
8 Conformance . 45
Annex A (informative)  Use cases . 46
Annex B (informative)  Use case to requirements traceability . 110
Annex C (informative)  Requirements traceability matrix . 127
Annex D (normative)  Extension procedures . 143
Annex E (normative)  Profile A for J2735™ . 144
Annex F (normative)  Profile B for J2735™ . 148
Annex G (normative)  Profile C for J2735™ . 173
Bibliography . 233

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ISO TS 19091:2019 (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 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 of 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
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 19091:2017), which has been
technically revised.
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 TS 19091:2019 (E)
Introduction
Cooperative-ITS (C-ITS) is a promising and remarkable advancement of intelligent transport systems
(ITS). Numerous cooperative applications are specified that open up new possibilities to make traffic
safer, more efficient, and smarter. Technologies are developed and improved to realize and support
those new services and applications. To enable those applications, information needs to be reliably
communicated between the stationary infrastructure and mobile vehicles.
This document describes the use cases for several applications that address safety, mobility, and
ecological sustainability. Each use case has information needs that communication between vehicles
and the infrastructure facilitate. It then identifies the information needs for the applications and the
requirements to satisfy them. In turn, it maps the requirements into data frames and data elements to
fulfil the requirements within the specified message set.
ISO 22951 has a relationship to this document. PRESTO addresses its user needs through the
implementation of a specific system architecture similar to that described in NTCIP 1211. This
architecture includes traffic signals, message signs, routing systems, human machine interfaces, and
fixed detection locations. Many of PRESTO's data value details are “left undefined to allow for
discretional definition by each country.” The PRESTO architecture detects priority requesting vehicles
by installing specific detection equipment at these locations.
This document uses a similar set of user needs to develop the message set between vehicles and the
roadside equipment they interface. This document does not address the system architecture other than
data needed to fulfil the user needs that will be managed elsewhere in the architecture. It details data
values and structures in order to define the interface between these two devices. Routing information is
supported in the architecture through other mechanisms and is not a need supported by the vehicle to
roadside equipment information flows. The user needs also provide for priority by approach, a
preconfigured strategy, and ingress/egress lane requests. This document is based on vehicles
periodically broadcasting their location and trajectory information to other vehicles and the roadside
infrastructure. This document complements ISO 22951 as it provides for vehicle location and request
information directly from connected vehicles rather than the detection of the vehicles from other fixed
sensing equipment. It does not address the architecture data flows and operations that are detailed
within ISO 22951. In other terms, this document provides a connected vehicle alternative for request
and status communication without impacting the back office or local intersection operations of priority
management.
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ISO TS 19091:2019 (E)
Intelligent transport systems — Cooperative ITS — Using V2I
and I2V communications for applications related to signalized
intersections
1 Scope
This document defines the message, data structures, and data elements to support exchanges between
the roadside equipment and vehicles to address applications to improve safety, mobility and
environmental efficiency. In order to verify that the defined messages will satisfy these applications, a
systems engineering process has been employed that traces use cases to requirements and
requirements to messages and data concepts.
This document consists of a single document that contains the base specification and a series of
annexes. The base specification lists the derived information requirements (labelled informative) and
references to other standards for message definitions where available. Annex A contains descriptions of
the use cases addressed by this document. Annexes B and C contain traceability matrices that relate use
cases to requirements and requirements to the message definitions (i.e. data frames and data elements).
The next annexes list the base message requirements and application-oriented specific requirements
(requirements traceability matrix) that map to the message and data concepts to be implemented. As
such, an implementation consists of the base plus an additional group of extensions within this
document.
Details on information requirements, for other than SPaT, MAP, SSM, and SRM messages are provided in
other International Standards. The focus of this document is to specify the details of the SPaT, MAP,
SSM, and SRM supporting the use cases defined in this document. Adoption of these messages varies by
region and their adoption can occur over a significant time period.
This document covers the interface between roadside equipment and vehicles. Applications, their
internal algorithms, and the logical distribution of application functionality over any specific system
architecture are outside the scope of this document.
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.
NOTE As this document contains multiple profiles, the reference’s associated profile(s) are listed within
braces.
ISO 22951, Data dictionary and message sets for preemption and prioritization signal systems for
emergency and public transport vehicles (PRESTO) {A, B}
ISO 26684, Intelligent transport systems (ITS) — Cooperative intersection signal information and
violation warning systems (CIWS) — Performance requirements and test procedures {B}
SAE J2735:2016, Dedicated Short Range Communications (DSRC) Message Set Dictionary {A, B, C}
ARIB STD-T109, 700 MHz Band Intelligent Transport Systems {B}
ISO TS 19091:2019 (E)
ITS FORUM RC-010, 700 MHz Band Intelligent Transport Systems — Extended Functions Guideline,
published on March 15, 2012 {B}
ETSI/TS 102 894-2 V1.3.1, Intelligent Transport Systems (ITS); Users and applications requirements; Part
2: Applications and facilities layer; common data dictionary {C}
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
NOTE This document requires the understanding of the terminology used in the context of C-ITS and the
various devices involved in its implementation. As a result, the following terms contain important information to
set the context of the discussions which follow in the remaining sections of this document.
3.1
active manoeuvre
traveller paths (vehicles, pedestrians, bicyclists, etc.) that are allowed and have the right of way to enter
and move through the path
Note 1 to entry: This term supersedes allowed movements which means, in the context of this document, the
directions of manoeuvre that are legally allowed at a specific point in time based upon the state of the intersection
signals.
Note 2 to entry: Formerly known as active movement.
3.2
aftermarket safety device
ASD
connected device (3.8) in a vehicle (3.50) that operates while the vehicle is mobile, but which is not fully
integrated into the vehicle systems (as opposed to an OEM device that is pre-installed into the vehicle
systems)
3.3
allowed manoeuvre
traveller paths, e.g. vehicles, pedestrians, bicyclists, legally permitted to be performed when moving
from/into a lane (3.21) or between lanes
3.4
application
software designed to help users perform particular tasks or handle particular types of problems, as
distinct from software that controls the computer itself
Note 1 to entry: In the context of this document, it is a software program that provides functionality to realize
safety, mobility, and environmental benefits.
[SOURCE: ISO/IEC 26514:2008, 4.5, modified – Term ‘application software’ changed to ‘application’ and
Note 1 to entry added.]
ISO TS 19091:2019 (E)
3.5
Barnes dance
signal phase that stops vehicular manoeuvres and allows pedestrian manoeuvres to exclusively occur
across the intersection (3.17) including diagonally moving between corners
Note 1 to entry: Also referred to as a scramble, or “X” crossing. The term refers to Henry Barnes, a deceased traffic
engineer.
3.6
commercial motor vehicle
self-propelled or towed motor vehicle (3.50) used on a highway in commerce to transport passengers or
property when that vehicle is subject to regulations determined by the jurisdiction as to its use on the
road system of the jurisdiction in regulated circumstances and
a) has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or
gross combination weight, of 4 536 kg (10 001 pounds) or more, whichever is greater,
b) is designed or used to transport more than 8 passengers (including the driver) for compensation,
c) is designed or used to transport more than 15 passengers, including the driver, and is not used to
transport passengers for compensation
3.7
commercial motor vehicle on-board equipment
OBE (3.29) or ASD (3.2) mounted or in a vehicle (3.50) moving goods, heavy equipment, or people
Note 1 to entry: Vehicles include tractor-trailer combinations, panel trucks, and motor coaches.
3.8
connected device
device used to transmit to or receive messages from another device
Note 1 to entry: A connected device can be sub-categorized as an OBE (3.29), ASD (3.2), or RSE (3.39).
Note 2 to entry: In many cases, the connected device will be a DSRC (3.10) device, but other types of
communications could be supported.
3.9
connected vehicle
vehicle that contains a connected device (3.8)
3.10
dedicated short range communications
DSRC
technology for the transmission of information between multiple vehicles (3.50) (V2V) and between
vehicles and the transportation infrastructure (V2I and I2V) using wireless technologies
Note 1 to entry: It is characterized as having a limited distance (approximately 300 m) but is assumed to be low
latency to establish a connection and exchange information.
Note 2 to entry: Alternative definition - means of effecting (short-range) transactions between fixed equipment
and OBE(s) using an “air interface” comprising inductive or propagated signals between the fixed equipment and
OBE(s).
ISO TS 19091:2019 (E)
3.11
eco-driving
practice of driving in such a way as to minimize fuel consumption and emissions
3.12
eco-lane
dedicated lane(s) (3.21) optimized for eco-driving (3.11) similar to high-occupancy vehicle lanes
Note 1 to entry: However, these lanes are optimized for the environment using connected vehicle data.
Note 2 to entry: These lanes would be targeted toward low-emission, high-occupancy freight, public transport,
and alternative-fuel vehicles (AFV).
Note 3 to entry: Drivers would be able to opt-in to these dedicated eco-lanes to take advantage of eco-friendly
applications such as eco-speed limits, eco-cooperative adaptive cruise control, and connected eco-driving
applications.
3.13
electronic on-board recorder
device on-board a commercial vehicle (3.50) used to record driver information such as hours of service
3.14
inactive manoeuvre
traveller paths, e.g. vehicles, pedestrians, bicyclists, that are allowed and do not have the right of way to
enter and move through the path
3.15
intelligent transportation system
ITS
transport system in which advanced information, communication, sensor, and control technologies,
including the Internet, are applied to increase safety, sustainability, efficiency, and comfort
Note 1 to entry: Another appropriate meaning of the ITS acronym is integrated transportation systems, which
stresses that ITS systems will often integrate components and users from many domains, both public and private.
[SOURCE: ISO/TR 17465-1:2014, 2.3, modified – Note 1 to entry added.]
3.16
interoperability
ability of two or more systems or components to exchange information and to use the information that
has been exchanged
[SOURCE: IEEE 610.12-1990]
3.17
intersection
nexus where two or more approaches (links) (3.26) meet and vehicles (3.50) and other type of users
may travel between the connecting links
Note 1 to entry: Typically, this is a signalized intersection when considered by this document, and as such, the
modes of allowed manoeuvre are reflected in the signal phases, the geometry of the intersection, and the local
regulatory environment.
ISO TS 19091:2019 (E)
Note 2 to entry: The messages of J2735™ convey some of this intersection information to the travelling public.
Specifically, the MAP message (3.28) conveys the relevant road geometry, while the SPaT (3.44) message conveys
the current allowed manoeuvres and timing which control movements within the intersection.
Note 3 to entry: Alternative definition - GDF level 2 representation of a crossing which bounds a road or a ferry as
a complex feature composed of one or more GDF level 1 junctions, road elements and enclosed traffic areas.
3.18
interval
part of a traffic signal cycle during which signal indications (3.43) are stable and do not change
Note 1 to entry: In the SPaT (3.44) message, the current timing value for the remaining interval time estimate, as
well as the anticipated interval for yellow change (clearance) interval, is provided for each lane.
Note 2 to entry: Because signal interval times commonly change based on triggering events in many types of
signalling systems, the value provided in the SPaT message may represent a minimal value that is extended and
updated as the message is re-transmitted in real time.
3.19
interval sequence
order of appearance of signal indications (3.43) during successive periods of a traffic signal cycle
3.20
international traveller information system
ITIS
standard for incident phrases developed by the SAE ATIS Committee in conjunction with ITE TMDD and
other standards
Note 1 to entry: The ITIS documentation contains a wide variety of standard phrases to describe incidents and is
expected to be used throughout the ITS (3.15) industry. The codes found there can be used for sorting and
classifying types of incident events, as well as creating uniform human readable phrases. In the capacity of
classifying incident types, ITIS phrases are used in many areas. ITIS phrases can also be freely mixed with text and
used to describe many incidents.
3.21
lane
portion of the transportation network (typically a section of roadway geometry) which is being
described (its paths and various attributes about it) or referred to
Note 1 to entry: In the DSRC message set, the lane object is widely used. Lanes consist not only of sections of
drivable roadway traversed by motor vehicles, but other types of lanes including pedestrian and bicycle
walkways, trains and public transport lanes, and certain types of dividers and barriers.
Note 2 to entry: When used in describing an intersection, a lane is defined for each possible path into and out of
the intersection (in the MAP message). The current allowed manoeuvres applicable to the lane or its approach are
provided in the SPaT (3.44) message.
3.22
lane-use control signal
signal face displaying signal indications (3.43) to permit or prohibit the use of specific lanes (3.21) of a
roadway or to indicate the impending prohibition of such use
Note 1 to entry: Typically, these are arrow displays of varying colours.
ISO TS 19091:2019 (E)
Note 2 to entry: This document does not attempt to use signal colours/indications to reflect the allowed vehicle
operation, rather, the permitted movements are indicated and the state of the movement as explained later herein.
Each region has unique mechanisms for using the display signals to indicate the movement(s) allowed.
3.23
latency
time interval between the instant at which an instruction control unit issues a call for data
and the instant at which the transfer of data is started
Note 1 to entry: The reader is advised to select the appropriate definition based on the context.
[SOURCE: ISO/IEC IEEE 24765:2017, 3.2187, modified – “” added at beginning of definition.]
3.24
latency
time delay between sending a signal from one device and receiving it by another
device
Note 1 to entry: The reader is advised to select the appropriate definition based on the context.
[SOURCE: ISO/IEEE 11073-10201:2004, 3.31, modified – Note 1 to entry.]
3.25
link
communications channel being used in support of application data transfer needs
3.26
link
segment of a road network
Note 1 to entry: While highway links are generally separated by one data collection node (such as an RSE or a
vehicle detector station), local road links tend to be limited by intersections with cross streets.
Note 2 to entry: Other common usages of the word “link,” such as those used in telecommunications, may also
appear in this document.
3.27
low-emissions zone
geographically defined area that seeks to restrict or deter access by specific categories of high-polluting
vehicles (3.50) to improve the air quality within the geographic area
Note 1 to entry: The low-emissions zone can be dynamic, allowing the operating entity to change the location,
boundaries, or time of the low-emissions zone.
3.28
MAP data message
MAP
data elements and frames comprising a message, the contents of which describe the geometry of a
roadway intersection (3.17)
Note 1 to entry: In the context of USDOT J2735™ SE Candidate, the MAP message provides the road geometry at an
intersection.
Not
...