ISO 17572-3:2015

INTERNATIONAL ISO
STANDARD 17572-3
Second edition
2015-01-15
Intelligent transport systems (ITS) —
Location referencing for geographic
databases —
Part 3:
Dynamic location references
(dynamic profile)
Systèmes intelligents de transport (SIT) — Localisation pour bases de
données géographiques —
Partie 3: Localisations dynamiques (profil dynamique)
Reference number
ISO 17572-3:2015(E)
©
ISO 2015

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ISO 17572-3:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015
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Published in Switzerland
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ISO 17572-3:2015(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms and attribute codes . 4
4.1 Abbreviated terms . 4
4.2 Attribute codes . 5
5 Objectives and requirements for a location referencing method . 6
6 Conceptual data model for location referencing methods . 6
7 Specification of dynamic location references . 6
7.1 General specification . 6
7.2 Location referencing building blocks . 7
7.2.1 General. 7
7.2.2 Points . 7
7.2.3 Attributes . 8
7.2.4 Next-point relationship .15
7.2.5 Attribute type list .15
8 Encoding rules .15
8.1 General .15
8.2 General point representation and selection rules .21
8.3 Location reference core encoding rules .21
8.3.1 Location selection .21
8.3.2 Location reference core point selection .22
8.3.3 Core point selection — Location points.22
8.3.4 Core point selection — Intersection points .23
8.3.5 Core point selection — Routing points .25
8.3.6 Intersection point attributes .27
8.3.7 Routing point attributes .28
8.3.8 Location reference core encoding parameters .29
8.4 Location reference extension encoding rules .29
8.4.1 General.29
8.4.2 Location reference extension necessity rules .30
8.4.3 Location reference extension point selection rules .30
8.4.4 Location reference extension encoding parameters .31
8.5 Coding of point locations.32
8.6 Coding of area locations .32
8.6.1 Coding of explicit area .32
8.6.2 Coding of implicit area .34
9 Logical data format specification .37
9.1 General .37
9.2 Data model definition.37
9.2.1 General.37
9.2.2 General data model .38
9.2.3 Linear location data model .38
9.2.4 Implicit area data model .39
9.2.5 Explicit area data model .40
Annex A (informative) Dynamic location reference, TPEG2 logical structure .41
Annex B (normative) Dynamic location reference, TPEG2 binary representation .58
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ISO 17572-3:2015(E)

Annex C (normative) Dynamic location reference, TPEG2 XML representation .66
Annex D (informative) Coding guidelines for dynamic location references .73
Annex E (informative) Compressed data format specification .79
Bibliography .103
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ISO 17572-3:2015(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT), see the following URL: Foreword — Supplementary information.
The committee responsible for this document is ISO/TC 204, Intelligent transport systems.
This second edition cancels and replaces the first edition (ISO 17572-3:2008), which has been technically
revised. It also incorporates Technical Corrigendum ISO 17572-3:2008/Cor1:2009.
ISO 17572 consists of the following parts, under the general title Intelligent transport systems (ITS) —
Location referencing for geographic databases:
— Part 1: General requirements and conceptual model
— Part 2: Pre-coded location references (pre-coded profile)
— Part 3: Dynamic location references (dynamic profile)
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ISO 17572-3:2015(E)

Introduction
A location reference (LR) is a unique identification of a geographic object. In a digital world, a real-
world geographic object can be represented by a feature in a geographic database. An example of a
commonly known location reference is a postal address of a house. Examples of object instances include
a particular exit ramp on a particular motorway, a road junction, or a hotel. For efficiency reasons,
location references are often coded. This is especially significant if the location reference is used to
define the location for information about various objects between different systems. For intelligent
transport systems (ITS), many different types of real-world objects will be addressed. Amongst these,
location referencing of the road network, or components thereof, is a particular focus.
Communication of a location reference for specific geographic phenomena, corresponding to objects in
geographic databases, in a standard, unambiguous manner is a vital part of an integrated ITS system,
in which different applications and sources of geographic data will be used. Location referencing
methods (LRMs, methods of referencing object instances) differ by applications, by the data model used
to create the database, or by the enforced object referencing imposed by the specific mapping system
used to create and store the database. A standard location referencing method allows for a common
and unambiguous identification of object instances representing the same geographic phenomena in
different geographic databases produced by different vendors, for varied applications, and operating on
multiple hardware/software platforms. If ITS applications using digital map databases are to become
widespread, data reference across various applications and systems has to be possible. Information
prepared on one system, such as traffic messages, has to be interpretable by all receiving systems. A
standard method to refer to specific object instances is essential to achieving such objectives.
Japan, Korea, Australia, Canada, the US, and European ITS bodies are all supporting activities of location
referencing. Japan has developed a Link Specification for VICS. In Europe, the RDS-TMC traffic messaging
system has been developed. In addition, methods have been developed and refined in the EVIDENCE
and AGORA projects based on intersections identified by geographic coordinates and other intersection
descriptors. After the publication of the first edition of this International Standard in 2008, TPEG had
changed to TPEG2. Modifications related to this change are captured in this second edition. In the US,
standards for location referencing have been developed to accommodate several different location
referencing methods.
This International Standard provides specifications for location referencing for ITS systems (although
other committees or standardization bodies can subsequently consider extending it to a more generic
context). In addition, this version does not deal with public transport location referencing; this issue will
be dealt with in a later version.
The International Organization for Standardization (ISO) draws attention to the fact that it is claimed
that compliance with this part of ISO 17572 can involve the use of a patent concerning procedures,
methods and/or formats given in this part of ISO 17572 in Clauses 8 and 9 and Annexes A, B, and C.
ISO takes no position concerning the evidence, validity, and scope of this patent right.
The holder of this patent right has ensured ISO that he/she is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In
this respect, the statement of the holder of this patent right is registered with ISO. Information can be
obtained from:
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ISO 17572-3:2015(E)

Panasonic, OBP Panasonic Tower, 2–1-61 Shiromi, Chuo-ku, Osaka, 540–6208,
Japan
Matsushita Electric Co., Ltd.
Blaupunkt GmbH Robert-Bosch-Str. 200, 31139 Hildesheim, Germany
Siemens AG Philipstr. 1, 35576 Wetzlar, Germany
Tele Atlas NV Reitscheweg 7F, 5232 BX ‘s-Hertogenbosch, Netherlands
Toyota Motor Co. (et al.) 1 Toyota-Cho, Toyota City, Aichi Prefecture 471–8571, Japan
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INTERNATIONAL STANDARD ISO 17572-3:2015(E)
Intelligent transport systems (ITS) — Location referencing
for geographic databases —
Part 3:
Dynamic location references (dynamic profile)
1 Scope
This International Standard specifies location referencing methods (LRMs) that describe locations
in the context of geographic databases and will be used to locate transport-related phenomena in an
encoder system as well as in the decoder side. This International Standard defines what is meant by such
objects and describes the reference in detail, including whether or not components of the reference are
mandatory or optional, and their characteristics.
This International Standard specifies two different LRMs:
— pre-coded location references (pre-coded profile);
— dynamic location references (dynamic profile).
This International Standard does not define a physical format for implementing the LRM. However, the
requirements for physical formats are defined.
This International Standard does not define details of the location referencing system (LRS), i.e. how the
LRMs are to be implemented in software, hardware, or processes.
This part of ISO 17572 specifies the dynamic location referencing method, comprising
— attributes and encoding rules
— logical data modelling
— TPEG physical format specification for dynamic location references,
— coding guidelines for dynamic location references;
— compressed data format specification.
It is consistent with other International Standards developed by ISO/TC 204 such as ISO 14825.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 17572-1, Intelligent transport systems (ITS) — Location referencing for geographic databases — Part 1:
General requirements and conceptual model
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 17572-1 and the following apply.
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3.1
bearing
angle between a reference direction and the direction to an object measured clockwise
Note 1 to entry: Unless otherwise specified, the reference direction is generally understood to be geographic north.
3.2
connection angle
CA
difference between side road bearing (3.23) and bearing (3.1) at a point
3.3
connection point
location point captured in the location reference core, which forms the start point of a path external
to the location
Note 1 to entry: Connection points are used to connect a location reference extension to a location reference core and
to connect linear locations to form a subnetwork. The connection point is identified using its connection point index.
Note 2 to entry: The connection point index is implicitly defined by the order of the points in a location reference.
3.4
connectivity
status of being topologically connected
Note 1 to entry: In a graph, two or more edges are said to be connected if they share one or more nodes.
3.5
coordinate pair
set of two coordinates (one longitude value and one latitude value), representing a position on the earth
model
Note 1 to entry: Within the scope of this International Standard, the earth model is embodied by ITRS and by
ITRF coordinates.
3.6
core point
CP
point belonging to the location reference core
3.7
destination location
location to be used as the end location of a journey for a route guidance application
3.8
extension point
EP
point belonging to the location reference extension
3.9
great circle
circle on the surface of a sphere that has the same circumference as the sphere
Note 1 to entry: The connection between two points on a sphere along the great circle passing through the said
two points is the shortest connection (airline distance or distance ”as the crow flies”).
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ISO 17572-3:2015(E)

3.10
intersection point
IP
core point representing an intersection, located at places where the road section signature at the
location changes
Note 1 to entry: The intersection point is one of the three defined core point types.
3.11
location point
LP
core point that bounds or is located on the location
Note 1 to entry: Location points can coincide with intersection points or routing points. The start and the end of
the location are always represented by a location point. Additional intermediate location points can be created to
represent the shape of the location. The location point is one of the three defined core point types.
3.12
location reference core
point or set of points that is available in any location reference
Note 1 to entry: The rules in Clause 8 control the data to be stored in the location reference core.
3.13
location reference extension
additional point or set of points, not belonging to the location reference core, available in a location
reference under special conditions
Note 1 to entry: The rules in Clause 8 specify the conditions under which a location reference extension is to be
used and control the data to be stored in a location reference extension.
3.14
next point
point that is directly (topologically) connected to a given point, in a direction that is defined by the
defined direction of the location
Note 1 to entry: A point can have zero or more next points.
3.15
next point relation
ordered pair of points (A, B) for which a direct connection exists from A to B along the path of the
referenced location
Note 1 to entry: In the road network, a direct connection between points A and B exists when point B can be
reached from point A via part of the road network, without visiting intermediate points in the location reference.
This excludes points connected in a GDF graph via a node representing an intersection-not-at-grade. Such points
are not considered to be directly connected.
3.16
parallel carriageway indicator
non-negative integer which indicates if a road segment contains more than one carriageway in parallel
in the direction of interest, and how many
3.17
precise geometry description
shape along the location, coded on the most detailed level of the digital map, lying in a corridor with a
defined perpendicular distance to the great circle connection between two successive points on a location
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3.18
road descriptor
full road number, or a significant substring of the official road name
Note 1 to entry: The road descriptor is ideally three to five characters in length.
3.19
road network location
location which has a one-dimensional and continuous structure, being part of a road network
Note 1 to entry: It is a continuous stretch of that road network as realized in the database, which can cover
different roads, and can be bounded on either side by an intersection. Alternatively it can be bounded on either
side by a position on a road.
3.20
road section signature
road signature
value of the attribute quadruple {functional road class, form-of-way, road descriptor, driving direction}
3.21
routing point
RP
point used to reconstruct the location by route calculation
Note 1 to entry: RPs are intended to allow point-based matching to the map database of the end user. When such
an RP match is found, the location then can be further reconstructed using the connectivity of the road network
as represented in the map database of the end user. The routing point is one of the three defined core point types.
3.22
side road section
road section which is not part of the location to be referenced, but connected to it via an at least
trivalent junction
3.23
side road bearing
bearing of the side road section
3.24
side road direction
driving direction of the side road section
3.25
side road signature
road section signature of a side road section
3.26
status location
location to be used to position location-based status information
EXAMPLE A location for speed limit information or traffic level information.
4 Abbreviated terms and attribute codes
4.1 Abbreviated terms
AGORA Implementation of Global Location Referencing Approach
(Name of a European project 2000–2002)
DLR dynamic location reference (also known as DLR1 because this is the first LRM under
dynamic profile)
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GCId generic component identifier
GDF Geographic Data Files (data model, data specification, and exchange standard for geo-
graphic data for road transport applications)
ISO International Organization for Standardization
ITRF International Terrestrial Reference Frame
ITRS International Terrestrial Reference System
ITS intelligent transport system
LR location reference
LRM location referencing method
LRS location referencing system
NLR network location reference
RDS Radio Data System (digital data channel on FM subcarrier)
RFU Reserved for Future Use
SSF Syntax, Semantics, and Framing Structure (TPEG ISO/TS 18234-2)
TMC Traffic Message Channel [system for broadcast of (digitally encoded) traffic messages
on RDS]
UML Unified Modelling Language
VLC Variable Length Coding
XML Extensible Markup Language
4.2 Attribute codes
AFR accessible for routing flag
BR bearing
CA connection angle
CPI connection point index
DCA distance measure CA
DD driving direction
DMB distance measure bearing
DSF destination flag
FC functional road class
FCM functional road class minimal
FW form of way
IT intersection type
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PCI parallel carriageway indicator
PD point distance
PDM D (attribute to measure distance on shapes)
perp-max
RD road descriptor
RDI road descriptor of intersection
RP routing point
SNI subnetwork index
5 Objectives and requirements for a location referencing method
For details, see ISO 17572-1:2014, Clause 4.
For an inventory of location referencing methods, see ISO 17572-1:2014, Annex A.
6 Conceptual data model for location referencing methods
For details, see ISO 17572-1:2014, Clause 5.
For examples of conceptual data model use, see ISO 17572-1:2014, Annex B.
7 Specification of dynamic location references
7.1 General specification
Dynamic location referencing is also known as the AGORA-C method and relies on specific attributes
that are mostly available in current digital map databases. Consequently, this LRM is adequate for LRSs
that have a physical format specification based on GDF. The method relies on real-time access by the
software to the original or translated values of the relevant attributes from its own digital map. This
LRM will also be called “on-the-fly referencing” because the location reference code can be immediately
discarded after internal definition of the location has been decoded. The dynamic location referencing
concept is designed to compensate for differences that might exist between the map used at the sending
system (the encoding side) and the map on board the receiving system (the decoding side). Such map
differences can be caused by the receiving system using an older map data set of the same supplier, or
vice versa, or the receiving system using a map data set from a different supplier.
Dynamic location referencing is often not as compact as pre-coded location coding. However, it is generally
accepted that if dynamic location reference codes can on average stay within 50 bytes for problem and
status locations, this would be acceptable in terms of bandwidth occupation. The specification focuses
on LRSs for two purposes, and hence provides two building blocks.
— Location reference core
The location reference core is applicable to problem and status locations, e.g. road traffic messages.
The location reference core is intended to provide location information much like ALERT-C location
[10]
referencing for which this specification actually intends to provide a ligh
...