ISO 10711:2012

Intelligent Transport Systems — Interface Protocol and Message Set Definition between Traffic Signal Controllers and Detectors

ISO 10711:2012 defines protocols and message sets between traffic detectors and traffic signal controllers. It is applicable to the various types of traffic detector technologies currently in use for real-time traffic signal controls. It defines message sets that contain data collection and control protocol for three different types of detectors of traffic signal control systems: detectors that deal with occupancy information; detectors that deal with image information; and detectors that deal with vehicle identification. ISO 10711:2012 is limited to parameter generation to be used for traffic signal controls and for the interface between traffic signal controllers and detectors.

Systèmes intelligents de transport — Protocole d'interface et définition des ensembles de messages entre régulateurs de signaux de circulation et détecteurs

General Information

• Status: Published
• Publication Date: 11-Jan-2012
• ICS: 03.220.01 - Transport in general
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ISO/TC 204 - Intelligent transport systems
• Drafting Committee: ISO/TC 204/WG 9 - Integrated transport information, management and control
• Current Stage: 9092 - International Standard to be revised
• Due Date: 08-Nov-2024
• Completion Date: 08-Nov-2024

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10711
First edition
2012-01-15
Intelligent Transport Systems — Interface
Protocol and Message Set Definition
between Traffic Signal Controllers and
Detectors
Systèmes intelligents de transport — Protocole d'interface et définition
des ensembles de messages entre régulateurs de signaux de
circulation et détecteurs
Reference number
©
ISO 2012
©  ISO 2012
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ii © ISO 2012 – All rights reserved

Contents Page
Foreword . iv
Introduction . v
1  Scope . 1
2  Normative references . 2
3  Terms and definitions . 2
4  Abbreviated terms . 2
5  Interface protocol for traffic controller . 3
5.1  Relationship to other standards . 3
5.2  Identification detector index . 3
5.3  Detector classification . 4
6  Interface messages for traffic signal controller . 5
6.1  General frame structure . 5
6.2  Detector information messages structure . 7
Annex A (normative) Interface Protocol Message Set Definition between Traffic Signal Controllers
and Detectors data structure and data type definition . 16
Annex B (informative) Interface Protocol and Message Set Definition between Traffic Signal
Controllers and Detectors implementation example . 23
Bibliography . 25

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 10711 was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.

iv © ISO 2012 – All rights reserved

Introduction
Real-time traffic signal control systems use traffic detectors to obtain traffic flow information. Each detector
has its own method for collecting traffic information. Most popular is the loop detector which reports traffic data
through detection of vehicle occupancy. Each method supporting different forms of detection has its own
merits and disadvantages and uses a variety of message sets and protocols for communication which
complicates their integration into systems.
There are two methods for integrating different types of traffic detectors. One method is to select and/or
analyse the necessary information from detectors using their own message sets. The second method is to
standardize the message sets and protocols to be used for the interface between detectors and traffic signal
controllers. The former has the disadvantage that the signal controller must be customized each time a new
detector type is introduced. The latter approach has the advantage of supporting consistent collection of traffic
data without consideration of detectors' detection principles and characteristics. Thus, the second method has
advantages when the use of the data is known.
This International Standard defines detector message sets applicable to traffic signal control. There are three
different message sets according to the detection method: occupancy based; image processing based; and
vehicle identification based. All detectors should be assigned to one of these three categories. The message
sets do not contain hardware information and additional information that is not critical to the traffic signal
control.
Regardless of their physical functions or manufacturing methods, all current traffic detectors can use one of
the three types of message sets for communicating with traffic controllers. Using this International Standard,
there is no need to include specific manufacturer's technical codes as a part of the data exchange.
This International Standard allows the signal controller to query and change the detector settings for the
commonly applicable contents such as attributes identifying the installed location of the detector. For image
processing based detectors, this International Standard includes minimal well-known generic camera control
commands.
[2]
The encoding rules and lower layers of the OSI communications stack (e.g. transport) are left to national
standards.
The benefits are
a) all detectors can adopt one of the three types of predefined message sets, thus configuration of traffic
detector system for traffic signal control becomes more simple regardless of hardware properties and
manufacturing method,
b) it is not necessary to replace or revise traffic signal controller software when a new type of detector is
installed and a new detector adopting one of the three message sets will not have communications
interoperability problems, as all of the necessary information items for signal control have been
considered, and
c) minimizing the communications load achieved with the compact size of predefined information; this
advantage can be applicable to short range wireless communication with its weakness in the multi-
channel simultaneous communication owing to hand-shaking and frequency interference.
Annex B provides an informative example of how the interface protocol and message sets are implemented.

INTERNATIONAL STANDARD ISO 10711:2012(E)

Intelligent Transport Systems — Interface Protocol and
Message Set Definition between Traffic Signal Controllers and
Detectors
1 Scope
This International Standard defines protocols and message sets between traffic detectors and traffic signal
controllers. It is applicable to the various types of traffic detector technologies currently in use for real-time
traffic signal controls. The scope of this International Standard is limited to parameter generation to be used
for traffic signal control and for the interface between traffic signal controllers and detectors.
This International Standard defines message sets that contain data collection and control protocol for three
different types of detectors of traffic signal control systems:
 detectors that deal with occupancy information;
 detectors that deal with image information;
 detectors that deal with vehicle identification.
The scope of this International Standard does not include the following cases:
 interfaces between sensors [including tag or on-board units (OBU)] and detector controllers;
 interfaces between traffic signal controllers and centres;
 when signal controllers only relay data from field-side detectors to central computers;
 when signal controllers receive unencoded electrical signals from cable-connected detectors and not
data from detectors.
Physical scope is limited to the communication interface between traffic signal controllers and traffic detectors.
The scope does not include the interface between the traffic detector and its own controller.
Tag or OBU
Traffic
controller
assembly
Image
Detector
Controller
Loop
Figure 1 — Physical scope
This International Standard is limited to the definition of the message sets used to exchange detector
information relevant for traffic control and the logical rules governing the exchange of these messages.
2 Normative references
The following referenced documents are indispensable for the application 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 15784-3:2008, Intelligent transport systems (ITS) — Data exchange involving roadside modules
communication — Part 3: Application profile-data exchange (AP-DATEX)
ISO 14827-2:2005, Transport information and control systems — Data interfaces between centres for
transport information and control systems — Part 2: DATEX-ASN
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15784-3 and the following apply.
3.1
occupancy based detector
detector that detects vehicles and traffic characteristics based on the state of the occupancy using methods
such as loop or magnetic detectors
3.2
image processing based detector
detector that detects vehicles based on the real-time image data from the digital camera which has virtual
sensing lines for estimating queue length or other parameters in approaching lanes
3.3
vehicle identification based detector
detector that detects vehicle identities based on wireless communication with tags or on-board units (OBU) in
the vehicle, which transmits the vehicle's identity information to the traffic signal controller
3.4
detection zone
area on the road surface where the target or the group of targets actuates the detector
NOTE Adapted from DS/ENV 13563.
3.5
detector information type
information type that designates the type of information from linked detectors which can be occupancy based,
image processing based or vehicle identification based
3.6
direction discrimination
direction of travel of a target within the detection zone
NOTE Adapted from DS/ENV 13563.
4 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
ID Identifier
IPMSTSCD Interface Protocol and Message Set Definition between Traffic Signal Controllers and Detectors
MIB Management Information Base
2 © ISO 2012 – All rights reserved

OBU On-Board Unit
OSI Open System Interconnection
PDU Protocol Data Unit
RSE Roadside Equipment
5 4BInterface protocol for traffic controller
5.1 6BRelationship to other standards
For the interface, this International Standard defines for each application the scope of the
1) framework in the protocol stack,
2) object encoding rules, and
3) transportation management protocol.
The interface defined within this International Standard secures interoperability by adopting the lower layer of
the protocol stack and specified standards for encoding rules, transport management rules and data
structures. The criteria for detector controller and traffic signal controller define the designating method for the
detectors.
The information should be exchanged according to the protocol profile defined in ISO 15784-3 and
ISO 14827-2.
5.2 7BIdentification detector index
5.2.1 11BIdentification method
A traffic signal controller collects data from each connected detector controller using the message sets defined
in this International Standard. Each detector controller reports information about its detectors, with each
detector identified by a unique sequential identifier. However, since the traffic signal controller may be
connected to multiple detector controllers, the traffic signal controller shall, where required, support a cross-
reference table that translates the local detector identifier into an identifier that is unique for the entire scope of
the traffic signal operation, as shown in Figure 2.
ID Type
Taffic
Image Type
2 Signal
Controller
detector detector logical detector
index numbers
controller index numbers
wireless
of detector controller index numbers of signal controller
device
Loop
Type
Loop
Type
Loop
Type
detector index
cross reference table
Figure 2 — Detector identification concept (example)
...