ISO 19082:2025

International
Standard
ISO 19082
First edition
Intelligent transport systems —
2025-11
Definition of data elements and
data frames between roadside
modules and signal controllers for
cooperative signal control
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Conformance . 3
6 Use cases . 3
6.1 General .3
6.2 Macroscopic signal control systems .3
6.3 Micro signal control systems .4
6.4 Data frames for the use cases .6
7 Data elements and frames . 7
7.1 General .7
7.2 Data elements .7
7.3 Data frames for processed and statistical data . 12
Annex A (normative) ASN.1 modules .20
Annex B (informative) Data model .27
Annex C (informative) Relationship with existing standards .29
Bibliography .33

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 first edition of ISO 19082 cancels and replaces the first edition of ISO/TS 19082:2020, which has been
technically revised.
The main changes are as follows:
— ASN.1 modules have been specified;
— certain data elements have been imported from other documents and the related references have been
clarified;
— an architecture reference model has been added.
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.

iv
Introduction
Signal controllers and traffic control centres optimize signal timings based on real-time traffic information for
each approach. For example, signal controllers can extend the green time for an approach with a long queue.
The aim of this document is to define data elements and data frames that are useful for optimising local and
coordinated signal operation.
ISO 22951, on the pre-emption and prioritization signal system for emergency and public transport vehicles
(PRESTO), specifies the message sets for signal system pre-emption and priority for transit vehicles,
including communications between roadside modules and signal controllers. This document complements
ISO 22951 by defining message sets for traffic information that is useful for optimizing normal signal
operations. Thus, signal controllers and traffic management centres can generate signal timings referring
to the messages of ISO 22951 (PRESTO) and this document. The relationship between this document and
ISO 22951 is shown in Annex C.
The arrows in Figure 1 illustrate message flows that are within scope of this document.
Figure 1 — Physical scope of this document
Figure 2 shows where this document is positioned within the ITS station architecture, as defined in
ISO 21217.
Figure 2 — Architecture reference model
The messages specified in this document may be sent and received based on the facilities layer and lower
layer of the ITS station architecture. When using the ITS station architecture, for communicating the data
specified in this document, the communication profile can be appropriately selected using the process
specified in ISO 17423. The lower layer communication services are provided by the communication profile

v
hander (CPH) specified in ISO 17429. ITS station management and communications between ITS stations are
specified in ISO 24102-6.
The data elements and data frames in this document are typically exchanged using well-known internet
protocols, such as UDP/IP or TCP/IP. IPsec, DTLS and TLS can be used for security.
The data structure follows the framework specified in ISO 14817-1, and the data elements and data frames
are described by description name, object identifier, definition, and data type following ISO 14817-1. The
specifications of this document complement those from ISO/TS 19091 and other standards.
NOTE Roadside modules can generate data based on inputs from vehicle detectors and/or probe data transmitted
by vehicles. This document does not address how the roadside module generates the data, it only addresses
communication after receiving and processing raw data from one or more sources.
EXAMPLE A roadside module may calculate vehicle volume, average speed, and queue length by utilizing data
from vehicle detectors and probe information.

vi
International Standard ISO 19082:2025(en)
Intelligent transport systems — Definition of data elements
and data frames between roadside modules and signal
controllers for cooperative signal control
1 Scope
This document specifies data elements and data frames for messages
a) exchanged between roadside modules and:
1) signal controllers;
2) traffic management centres, and/or;
3) other roadside modules.
b) exchanged between traffic management centres and signal controllers.
This document addresses the data in the application layer of the OSI (Open Systems Interconnection)
reference model.
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 14817-1, Intelligent transport systems — ITS central data dictionaries — Part 1: Requirements for ITS data
definitions
ISO 17419, Intelligent transport systems — Globally unique identification
ISO 10711, Intelligent Transport Systems — Interface Protocol and Message Set Definition between Traffic
Signal Controllers and Detectors
SAE J2735, Dedicated Short Range Communications (DSRC) Message Set Dictionary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14817-1 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
adaptive signal control
signal control concept where vehicular traffic in a network is detected at one or more points upstream and/
or downstream and algorithmically combined with other information to predictively optimize traffic signal
operation
3.2
conflicting turn
turn manoeuvre that conflicts with another manoeuvre at an intersection
3.3
cooperative signal control
signal control utilizing not only vehicle detector data but also V2I communication data
3.4
dilemma zone
area upstream of a traffic signal in which different drivers are likely to make different decisions on whether
to continue through or stop at the signal as they see the signal indication change from green to yellow
Note 1 to entry: There are two types of dilemma zones. Type I occurs when yellow and red clearance times are too
short for a driver to either stop or clear the intersection before the beginning of a conflicting phase. Type II, also
known as an “Option Zone”, or “Indecision Zone”, occurs as the result of different drivers making different decisions on
whether to go or stop, upon the change from a green to yellow indication.
3.5
flow rate
equivalent hourly rate at which vehicles, bicycles or persons pass a point on a lane, roadway, or other traffic
way, computed as the number of vehicles, bicycles, or persons passing the point, divided by the time interval
(usually less than 1 h) in which they pass
Note 1 to entry: It is expressed as vehicles, bicycles or persons per hour.
3.6
phase
signal controller timing unit associated with the control of one or more movements
3.7
probe data
vehicle sensor information, formatted as probe data elements and/or probe messages, that is processed,
formatted, and transmitted to a roadside module to create a good understanding of the driving environment
3.8
queue
line of vehicles, bicycles, or persons waiting to be served by the system in which the flow rate from the front
of the queue determines the average speed within the queue
Note 1 to entry: Slowly moving vehicles or people joining the rear of the queue are usually considered part of the
queue. The internal queue dynamics can involve starts and stops. A faster-moving line of vehicles is often referred to
as a moving queue or a platoon.
3.9
roadside module
group of components, or applications, installed at the roadside that can be controlled or monitored, or both,
by a remote entity
3.10
signal controller
roadside module that manages the right-of-way at an intersection, typically by displaying green, yellow and
red indications to the intersection’s various approach lanes

4 Abbreviated terms
PRESTO Data Dictionary and Message Sets for Pre-emption and Prioritization Signal System for Emer-
gency and Public Transport Vehicles
ITS Intelligent Transport Systems
UDP User Datagram Protocol
TCP Transmission Control Protocol
IP Internet Protocol
IPsec Security Architecture for Internet Protocol
DTLS Datagram Transport Layer Security
TLS Transport Layer Security
ASN.1 Abstract Syntax Notation One
5 Conformance
In order to claim conformance with this document, the structure of data elements and the data frames
between roadside modules and signal controllers shall follow the data types described in Clause 7.
6 Use cases
6.1 General
This clause describes several usage examples where data defined within this document can be used.
6.2 Macroscopic signal control systems
Many adaptive signal control systems perform macroscopic control functions on a central computer, which
determines the signal parameters such as cycle length, split and offset based on congestion information.
These systems aim to reduce delays and stops by improving the timing efficiency of green indications at
critical intersections and maximizing traffic capacity.
Conventionally, volumes and occupancy from vehicle detectors have been used for the input of these systems;
the introduction of connected vehicles now allow probe data to be used for this purpose (Figure 3). Probe
data can be received over short range communication technologies and processed by roadside modules; the
processed data can then be transferred to traffic control centres. Probe data can also be collected via wide
area communication. In this case, the central computers process the collected raw probe data and calculate
signal parameters by combining processed probe data transferred from roadside modules. This process
shall not be duplicated.
The central computer calculates optimal signal parameters and transmits them to signal controllers every a
few minutes. Sometimes micro control functions described in 6.2 are combined with macro control functions
by signal controllers.
Figure 3 — Macroscopic signal control system
An example flow of macroscopic signal control system is as follows:
a) Roadside modules with detectors gather raw data of the presence and position of vehicles.
b) Vehicles equipped with in-vehicle units transfer probe data to roadside modules.
c) The roadside modules calculate some characteristic data of intersections like flow rate, average speed,
divergence rate, and vehicle type ratio by utilizing data from vehicle detectors and probe data.
d) The roadside modules transfer the calculated data to the traffic management centre.
e) The traffic management centre calculates the optimum parameters for intersections like splits, cycles
and offsets and transfers them to the signal controllers.
Another example of macroscopic signal control system is as follows:
a) The vehicle detectors gather raw data of the presence of vehicles and the positions of vehicles.
b) Vehicles which equip in-vehicle units transfer probe data to roadside modules.
c) The roadside modules assemble data of each vehicle like position, speed, stop position. The roadside
modules can generate snapshots of vehicle positions.
d) The roadside modules transfer the assembled data to the traffic management centre.
e) The traffic management centre calculates some characteristic data of each intersection like flow rate,
average speed, divergence rate and vehicle type ratio utilizing data from roadside modules, then
calculates the optimum parameters for intersections like splits, cycles, and offsets and transfers them
to the signal controllers.
6.3 Micro signal control systems
Roadside modules are usually installed near an intersection in local control systems. Probe data is
collected via short range wireless communication (referred to as "localized communications" in ITS, see
e.g. ISO 21215, ISO 29281-1). Traffic signals with actuated conflicting turns are an example of this kind of
system. This system optimizes the left-turn phase time according to the presence and numbers of queued
vehicles. Figure 4 shows an example of a left hand turn for roads that drive on the right.

Key
1 signal controller
2 roadside module with wireless equipment
3 probe data
Figure 4 — Actuated conflicting turns
An example flow of left-turn control systems is as follows:
a) The vehicle detectors gather raw data of the presence of vehicles and the position of vehicles.
b) Vehicles which equip in-vehicle units transfer probe data to roadside modules.
c) The roadside modules assemble data of vehicle presence and each vehicle’s position and speed.
d) The roadside modules calculate the queue length of vehicles, and the time gap between vehicles.
e) The roadside modules transfer the processed data to the signal controller.
f) The signal controller decides the phase timing with the processed data. For example, the signal
controller extends the green phase if vehicles are present in a specified area.
Another example of micro signal control systems is a dilemma zone control system. The dilemma zone
control system minimizes the number of vehicles in the dilemma zone by adjusting the start time of yellow
and red signal phase either earlier or later, based on observed vehicle locations and speeds. Figure 5 shows
an example.
Key
1 signal controller
2 roadside module with wireless equipment
3 probe data
4 dilemma zone of 40 km/h vehicle
5 dilemma zone of 70 km/h vehicle
Figure 5 — Dilemma zone control systems
An example flow of dilemma zone control systems is as follows:
a) The vehicle detectors gather raw data of the presence of vehicles and the position of vehicles.
b) Vehicles which equip in-vehicle units transfer probe data to roadside modules.
c) The roadside modules pick up the data of important vehicles for the dilemma zone control system.
d) The roadside modules transfer the processed data to the signal controller.
e) The signal controller decides the phase timing with the processed data. For example, the signal
controller finishes the green phase if a vehicle enters the dilemma zone.
6.4 Data frames for the use cases
In these use cases, the data frames in Table 1 shall be used.

Table 1 — Data frames for use cases
Data frames Macroscopic signal control Micro signal control
Snapshot.vehiclePositions:VehiclePositionSnapshot Y Y
Intersection.snapshot:Measure Y Y
IntersectionLane.approachingVehicleDistance:Measure Y
Intersection.latestStartupLostTimes:measure Y
IntersectionLane.FlowRatePerLane:measure Y
IntersectionApproach.DivergenceRate:percent Y
Intersection.VehiclePresent:boolean Y
Geolocation.VehiclePresent:boolean Y
Intersection.VehicleAmount:quantity Y
Geolocation.VehicleAmount:quantity Y
Intersection.averageHeadway:duration Y
Intersection.queueLength:measure Y Y
Intersection.stopPositions:measure Y
Link.travelTime:duration Y
Intersection.meanVehicleSpeed:measure Y
Intersection.VehicleSpeed:measure Y
Intersection.largeVehiclePercentage:percent Y
Intersection.VehicleGapSize:measure Y Y
Intersection.CycleLength:duration Y
Intersection.Split:percnent Y
Intersection.relativeOffset:duration Y
Intersection.absoluteOffset:duration Y
NOTE: the data frames with “Y” are utilized for the use cases.
7 Data elements and frames
7.1 General
In this clause the data elements and frames for communications between roadside modules and signal
controllers, traffic management centres, and/or other roadside modules are defined. These data elements
and frames are used for realizing signal controls in Clause 6.
These data elements and data frames shall be of ASN.1 type ITS-SingleMsg19082Types specified in Annex A,
and shall constitute the message sets in Annex A. The allocation of ITSmsgSetID for this document and the
format of message sets shall conform to ISO 17419, as described in Annex A.
The relationship among data message, data elements and data frames are shown in Annex B.
7.2 Data elements
Data elements are the components of data frames specified in 7.3. Table 2 shows the data elements for
expressing each data.
Table 2 — Data elements
Descriptive name Oid Definition Multiplicity Data type Unit of Valid value rule
measure
Type-measure-kmh-u8
IntersectionLane. The arithmetic mean speed of 1 1 kilometre
the vehicles travelling in the per hour
meanVehicleSpeed:measure
intersection lane.
IntersectionLane. The compass direction from 1 Type-code-compass16 code
which vehicles enter the inter-
(North,North-
approachingFrom:code
section. northeast, Northeast,
East-northeast,
East,East-southeast,
Southeast,South-
southeast,
South, South-
southwest,Southwest,
West-southwest,West,
West-
northwest,Northwest,
North-northwest)
Type-measure-
IntersectionLane. The distance from the leading 1 metre
metre-s16
edge of an approaching vehicle
approachingVehicleDistance:
(-32768.32767)
and the stop line associated
measure
with the vehicle's lane.
Type-measure-pcph-u16
IntersectionLane. The number of queued au- 1 individual
thorized entities that flow vehicles per
freeFlowRate:measure
across the stop bar for the one hour
intersection lane per unit of
time after the start-up time
has expired and before the
signal terminates its green
time. It is expressed in the rate
of equivalent entities per hour.
The type of authorized vehicle
is defined by the definition of
the intersection lane in the
intersection map (e.g. a vehicle
would be the authorized ve-
hicle in a lane designated for
vehicles).
Type-duration-sec-u16
Vehicle.travelTime:duration The average time required for 1 second
vehicles to traverse the link.
Type-measure-kmh-u16
Vehicle.Speed:measure The instantaneous speed of 1 1 kilometre
the vehicle. per hour
Table 2 (continued)
Descriptive name Oid Definition Multiplicity Data type Unit of Valid value rule
measure
Type-code-vehicle-
Vehicle.Type:code Vehicle type, as defined in 1 code
type-iso3833
ISO 3833.
Type-percent
IntersectionLane.largeVehiclePercentage The percentage of large motor 1 percent
vehicles within the stream of
:percent
entities crossing the stop bar.
Type-measure-
Vechile.downstreamSpacing:measure The distance between the 1 centimetre The value 4095
centimetre-u12
leading edge of the vehicle to indicates that
the trailing edge of the next no vehicle is
vehicle in front of it in the detected within
same lane. 4 094 cm in
front of it within
the same lane.
Type-percent
IntersectionApproach.straightPercent The percentage of vehicles on 1 percent
the intersection approach that
:percent
have gone straight in the past
5 minutes.
Type-percent
IntersectionApproach.rightPercent The percentage of vehicles on 1 percent
the intersection approach that
:percent
have gone right in the past
5 minutes.
Type-percent
IntersectionApproach.leftPercent The percentage of vehicles 1 percent
on the intersection approach
:percent
that have gone left in the past
5 minutes.
Type-boolean
IntersectionLane.vehiclePresent An indication of whether there 1 boolean
are any vehicles present in a
:boolean
specified area of the approach
lane.
Type-quantity-u16
IntersectionLane.vehicleAmount A count of how many vehicles 1 number
are present in a specified area
:quantity
of the approach lane.
Type-duration-sec-u16
IntersectionLane.averageHeadway The average time between the 1 second
leading edge of two subse-
:duration
quent vehicles at an intersec-
tion as they cross the stop line
once the signal has been green
for 6 seconds and as averaged
over a predetermined time.
Table 2 (continued)
Descriptive name Oid Definition Multiplicity Data type Unit of Valid value rule
measure
Type-measure-
IntersectionLane.queueLength:measure The length of a series of vehi- 1 metre The value 4 095
metre-u12
cles whose flow is controlled shall mean a
by the lead vehicle. length in excess
of 4 094 m.
NOTE: A queue boundary is
typically determined by a dis-
tance gap for stopped vehicles,
a time gap for high speed ve-
hicles, or a combination of the
two for slow moving vehicles.
Type-code- The defined
SignalPhase.currentindication:code The indication currently being 1 code
signalphase- domain is
output for the signal phase.
indication
ENUMERATED {
Unavailable
(0),
Dark (1),
Stop-then-
proceed (2),
Stop-and-
remain (3),
Pre-
movement (4),
Permissive-
movement-
allowed (5),
Protected-
movement-
allowed (6),
Permissive-
clearance
(7),
Protected-
clearance
(8),
Caution-
conflicting-
traffic (9)
}
Table 2 (continued)
Descriptive name Oid Definition Multiplicity Data type Unit of Valid value rule
measure
Type-duration-sec-u16
IntersectionLane.latestLostTime The time required for the 1 second
second queued vehicle to cross
the stop line after the associ-
ated phase changed. If fewer
than two vehicles were queued
at the start of green, the value
shall be 0.
Type-duration-sec-u16
Signal.CycleLength:duration The time required for a com- second
plete sequence of signal indica-
tions. Expressed in seconds.
Type-percent
SignalPhase.Split:percent The time allotted for the phase percent
during coordinated opera-
tions. Expressed in percent.
Type-duration-sec-u16
Signal.Offset:duration The time relationship between second
coordinated phases defined
reference point and a mas-
ter reference. Expressed in
seconds.
7.3 Data frames for processed and statistical data
Data frames consist of the data elements specified in 6.1 or other data frames. Table 3 shows the data frames
for expressing processed and statistical data.

Table 3 — Data frames
Descriptive name Oid Definition Multiplicity Data type
Snapshot.vehiclePositions:VehiclePositionSnapshot A summary of the location of SEQUENCE {
vehicles at an instant in time.
time DateTime,
vehPositions (SIZE(0.65535) ) OF
vehicle.
}
IntersectionLane.snapshot:Measure: A summary of the location of SEQUENCE {
vehicles of a lane of an inter-
time DateTime,
section at an instant in time.
identifier Intersection ID,
approach IntersectionLane.
approachingFrom,
identifier Lane ID,
vehPositions (SIZE(0.65535) ) OF
Position3D
}
IntersectionLan
...