EN ISO 14819-3:2004
(Main)Traffic and Travel Information (TTI) - TTI messages via traffic message coding - Part 3: Location referencing for ALERT-C (ISO 14819-3:2004)
Traffic and Travel Information (TTI) - TTI messages via traffic message coding - Part 3: Location referencing for ALERT-C (ISO 14819-3:2004)
ISO 14819-3:2004 primarily addresses the needs of RDS-TMC ALERT-C messages, which are already being implemented. However, the modular approach used here is intended to facilitate future extension of the location referencing rules to other traffic and travel messaging systems.
The location referencing rules defined in ISO 14819-3:2004 address the specific requirements of Traffic Message Channel (TMC) systems, which use abbreviated coding formats to provide TTI messages over mobile bearers (e.g. GSM, DAB) or via exchange protocols like DATEX. In particular, the rules address the Radio Data System-Traffic Message Channel (RDS-TMC), a means of providing digitally-coded traffic and travel information to travellers using a silent data channel (RDS) on FM radio stations, based on the ALERT-C protocol.
Verkehrs- und Reisinformtionen (TTI) - TTI-Meldungen über Verkehrsmeldungscodierung - Teil 3: Ortskodierung für ALERT-C (ISO 14819-3:2004)
Information Trafic et Voyageurs (TTI) - Messages TTI via le codage de messages - Partie 3: Localisants pour ALERT-C (ISO 14819-3:2004)
L'ISO 14819-3:2004 couvre principalement les besoins des messages RDS-TMC selon le protocole ALERT-C, qui sont déjà en cours de mise en oeuvre. Cependant, l'approche modulaire utilisée ici est destinée à faciliter l'extension future des règles de référencement géographique à d'autres systèmes de messagerie d'informations trafic et voyageurs.
Les règles de référencement géographique définies dans l'ISO 14819-3:2004 couvrent les exigences spécifiques des systèmes TMC (Traffic Message Channel, Canal de messages routiers), qui utilisent des formats de codage abrégés pour fournir des messages TTI sur des supports d'information vers les mobiles (tels que GSM, DAB) ou par l'intermédiaire de protocoles d'échange comme DATEX. Ces règles traitent notamment du RDS-TMC qui est un moyen de fournir des informations trafic et voyageurs codées numériquement à des usagers utilisant un canal de données silencieux (RDS) diffusées par des stations de radiodiffusion en FM, sur la base du protocole ALERT-C.
Prometne in potovalne informacije (TTI) - Sporočila TTI prek kodiranih prometnih sporočil – 3. del: Navajanje lokacije za sistem ALERT-C (ISO 14819-3:2004)
General Information
- Status
- Withdrawn
- Publication Date
- 29-Feb-2004
- Withdrawal Date
- 03-Dec-2013
- Technical Committee
- CEN/TC 278 - Road transport and traffic telematics
- Drafting Committee
- CEN/TC 278/WG 4 - Traffic and traveller information (TTI)
- Current Stage
- 9960 - Withdrawal effective - Withdrawal
- Start Date
- 04-Dec-2013
- Completion Date
- 04-Dec-2013
Relations
- Effective Date
- 22-Dec-2008
- Effective Date
- 11-Dec-2013
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Get Certified
Connect with accredited certification bodies for this standard

BSI Group
BSI (British Standards Institution) is the business standards company that helps organizations make excellence a habit.
Sponsored listings
Frequently Asked Questions
EN ISO 14819-3:2004 is a standard published by the European Committee for Standardization (CEN). Its full title is "Traffic and Travel Information (TTI) - TTI messages via traffic message coding - Part 3: Location referencing for ALERT-C (ISO 14819-3:2004)". This standard covers: ISO 14819-3:2004 primarily addresses the needs of RDS-TMC ALERT-C messages, which are already being implemented. However, the modular approach used here is intended to facilitate future extension of the location referencing rules to other traffic and travel messaging systems. The location referencing rules defined in ISO 14819-3:2004 address the specific requirements of Traffic Message Channel (TMC) systems, which use abbreviated coding formats to provide TTI messages over mobile bearers (e.g. GSM, DAB) or via exchange protocols like DATEX. In particular, the rules address the Radio Data System-Traffic Message Channel (RDS-TMC), a means of providing digitally-coded traffic and travel information to travellers using a silent data channel (RDS) on FM radio stations, based on the ALERT-C protocol.
ISO 14819-3:2004 primarily addresses the needs of RDS-TMC ALERT-C messages, which are already being implemented. However, the modular approach used here is intended to facilitate future extension of the location referencing rules to other traffic and travel messaging systems. The location referencing rules defined in ISO 14819-3:2004 address the specific requirements of Traffic Message Channel (TMC) systems, which use abbreviated coding formats to provide TTI messages over mobile bearers (e.g. GSM, DAB) or via exchange protocols like DATEX. In particular, the rules address the Radio Data System-Traffic Message Channel (RDS-TMC), a means of providing digitally-coded traffic and travel information to travellers using a silent data channel (RDS) on FM radio stations, based on the ALERT-C protocol.
EN ISO 14819-3:2004 is classified under the following ICS (International Classification for Standards) categories: 35.240.60 - IT applications in transport. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 14819-3:2004 has the following relationships with other standards: It is inter standard links to ENV ISO 14819-3:2000, EN ISO 14819-3:2013, EN ISO 20524-1:2022, EN ISO 10846-2:1998, EN ISO 14819-1:2021, CEN/TS 16157-2:2011. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 14819-3:2004 is associated with the following European legislation: Standardization Mandates: M/018. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN ISO 14819-3:2004 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2004
1DGRPHãþD
SIST ENV ISO 14819-3:2003
3URPHWQHLQSRWRYDOQHLQIRUPDFLMH77,6SRURþLOD77,SUHNNRGLUDQLKSURPHWQLK
VSRURþLO±GHO1DYDMDQMHORNDFLMH]DVLVWHP$/(57&,62
Traffic and Travel Information (TTI) - TTI messages via traffic message coding - Part 3:
Location referencing for ALERT-C (ISO 14819-3:2004)
Verkehrs- und Reisinformtionen (TTI) - TTI-Meldungen über
Verkehrsmeldungscodierung - Teil 3: Ortskodierung für ALERT-C (ISO 14819-3:2004)
Information Trafic et Voyageurs (TTI) - Messages TTI via le codage de messages -
Partie 3: Localisants pour ALERT-C (ISO 14819-3:2004)
Ta slovenski standard je istoveten z: EN ISO 14819-3:2004
ICS:
03.220.20 Cestni transport Road transport
35.240.60 Uporabniške rešitve IT v IT applications in transport
transportu in trgovini and trade
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 14819-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2004
ICS 03.220.20; 35.240.60
English version
Traffic and Travel Information (TTI) - TTI messages via traffic
message coding - Part 3: Location referencing for ALERT-C
(ISO 14819-3:2004)
Verkehrs- und Reisinformtionen (TTI) - TTI-Meldungen über
Verkehrsmeldungscodierung - Teil 3: Ortskodierung für
ALERT-C (ISO 14819-3:2004)
This European Standard was approved by CEN on 3 November 2003.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14819-3:2004 E
worldwide for CEN national Members.
Contents
page
Contents. 2
Foreword. 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Abbreviations. 5
4 Location coding . 6
4.1 General. 6
4.2 Location tables . 6
4.3 TMC Location categories, types and subtypes . 10
4.4 Location table content . 10
4.5 Detailed junction referencing. 15
4.6 Detailed situation locations. 15
4.7 One and two way locations . 16
Annex A (normative) TMC Location categorie, types and subtypes. 19
A.1 Area locations . 19
A.2 Linear locations. 22
A.3 Point locations . 24
Annex B (normative) Location table numbers. 29
Annex C (informative) Background information. 30
C.1 Overall approach. 30
C.2 Methods . 32
Bibliography . 38
Foreword
This document (EN ISO 14819-3:2004) has been prepared by Technical Committee CEN/TC 278, "Road
transport and traffic telematics", the secretariat of which is held by NEN, in co-operation with ISO/TC 204
“Transport information and control systems”.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by September 2004, and conflicting national standards shall be
withdrawn at the latest by September 2004.
This document supersedes ENV ISO 14819-3:2000
Annexes A and B are normative. Annex C is informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain,
Sweden, Switzerland and the United Kingdom.
Introduction
This document sets out ways of specifying places and positions in traffic and travel information messages,
including RDS-TMC messages (the Radio Data System - Traffic Message Channel).
It defines the structure and semantics of location tables for Traffic Information Centres (TICs) and receivers.
b) TRAFFIC AND TRAVEL MESSAGES
1) Traffic and travel information is created and updated in an originating database, by human
operators or automated systems. Information is transferred to one or more remote systems by
means of messages.
2) In this context, a message is a collection of data which is exchanged to convey information for an
agreed purpose between two or more parties. Traffic and travel messages are digitally coded sets
of data exchanged by interested parties, which convey information about traffic, travel and/or
transport networks. Digital coding can be alphanumeric, as in EDIFACT, or binary, as in RDS-TMC.
3) The traffic and travel messages developed in programmes of the European Union are open, non-
proprietary proposals for standards intended to serve the public interest by facilitating
interconnection and interoperability of the relevant information systems.
c) LOCATION REFERENCING
1) Location references provide the means of saying where in traffic and travel messages.
1 Scope
This standard primarily addresses the needs of RDS-TMC ALERT-C messages, which are already being
implemented. However, the modular approach used here is intended to facilitate future extension of the
location referencing rules to other traffic and travel messaging systems.
The location referencing rules defined in this standard address the specific requirements of Traffic Message
Channel (TMC) systems, which use abbreviated coding formats to provide TTI messages over mobile
bearers (e.g. GSM, DAB) or via exchange protocols like DATEX. In particular, the rules address the Radio
Data System - Traffic Message Channel (RDS-TMC), a means of providing digitally-coded traffic and travel
information to travellers using a silent data channel (RDS) on FM radio stations, based on the ALERT-C
protocol.
2 Normative references
This European Standard incorporates, by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply
to this European Standard only when incorporated in it by amendment or revision. For undated references
the latest edition of the publication referred to applies (including amendments).
IEC 62106 Specification of the radio data system (RDS) for VHF/FM sound broadcasting in
the frequency range from 87,5 to 108,0 MHz (IEC 62106:2000)
EN ISO 14819-1 Traffic and Travel Information (TTI) - TTI Messages via traffic message coding -
Part 1: Coding protocol for Radio Data System - Traffic Message Channel
(RDS-TMC) using ALERT – C (ISO 14819-1:2003)
Geographic Data Files (ISO 14825:1996)
ENV ISO 14825
3 Abbreviations
For the purposes of this European Standard, the following abbreviations apply:
CENELEC Comité Européen de Normalisation ELECtrotechnique
DATEX DATa Exchange protocol for exchange of traffic and travel information between traffic centres
ECC Extended Country Code (an RDS feature)
EDIFACT Electronic Data Interchange For Administration Commerce and Transport
GDF Geographic Data Files (ENV ISO 14825 for modelling and exchange of geographic data for
transport telematics applications.)
RDS Radio Data System (digital information channel on FM sub carrier)
TIC Traffic Information Centre
TMC Traffic Message Channel
TTI Traffic and Travel Information
WGS 84 World Geodetic System 1984
4 Location coding
4.1 General
Location references used by RDS-TMC are covered by the location referencing rules defined in this section.
The ALERT-C coding protocol for RDS-TMC is defined in EN ISO 14819-1.
ALERT-C supports a digital, silent data broadcast service for motorists, providing information about many
kinds of traffic situations. This includes roadwork, weather and traffic incident information relating to major
national and international roads, regional roads and local or urban roads.
4.2 Location tables
4.2.1 General
Within RDS-TMC, locations are identified and referenced by their location code. A given RDS-TMC service
uses a pre-defined location table, containing the pre-stored details of the locations that can be referenced in
messages from that service.
A location code in such a message refers and serves as a tabular ‘address’ of the pre-stored location details
in the location table used by the service. A real world location may have more than one location code within
the same location table. However, within a given location table, each location code refers to one and only
one location. A location code has a number in the range 1 to 63,487.
Note: In ALERT-C, a further 2048 numbers are reserved for INTER-ROAD (see EN ISO 14819-1) and other forms of
referencing.
A table may contain a maximum number of 65,536 codes allocated in the following way:
Location code Use
0 reserved
1 - 63,487 free for normal location coding
63,488 - 64,511 for special purposes
64,512 - 65,532 for INTER-ROAD
64,533 - 65,535 special functions
Note: INTER-ROAD is a coding mechanism within ALERT-C to reference in a specific type of ALERT-C message (the
INTER-ROAD message) a location belonging to a different location table. This can be a table in the same country as well
as a table in another country.
4.2.2 Hierarchical structure
RDS-TMC location tables use a hierarchical structure of pre-defined locations. A system of pointers provides
upward references to higher-level locations of which the specified location forms a part.
Example: Kent would have an upward area reference to south-east England. South-east England may be referenced up
to the UK, then the British Isles, then Europe, etc. (Figure 1).
Key
A County of Kent
B South East England
C United Kingdom
D British Isles
E Europe
Figure 1 — Upward Area Referencing
Junction 25 on the M1 motorway in UK would have a linear reference to a motorway segment, e.g.
Leicester - Sheffield. This segment could then be referenced up to the whole road (the M1 Motorway).
Hierarchical tables help to make location referencing simple and unambiguous. A major benefit of
hierarchical tables is that they facilitate automated sorting and selection of information for users. However,
both hierarchical and unstructured tables are currently used in various applications.
4.2.3 Offsets
Most point locations and certain linear locations point to previous and next locations of the same type. This is
indicated by negative and positive offsets.
Example: Junction 25 on a motorway may be offset to Junction 26 in the positive direction, and to Junction 24 in the
negative direction. A sign convention adopted at the time of coding locations specifies the positive direction of travel
along each road (Figure 2).
Key
a positive direction
b negative offset
c positive offset
Figure 2 — Offsets
4.2.4 Location types
Location types and subtypes are required for language independence of the information given, and to tell the
receiving system what data fields to expect.
At the highest level, locations fall into three categories:
a) area locations
b) linear locations
c) point locations
Within each category, location types are distinguished (in principle) whenever a location is functionally
distinct in the way it shall be handled by the message recipient. Therefore a set of predefined location types
and subtypes is set out in annex A.
Subtypes can be used to give further details of (for example) facilities available at a particular location, such
as a service area. The current list, in annex A, will be added to as further needs are agreed.
Official translations of the language-independent terms that describe location types and subtypes should be
agreed on a national level.
4.2.5 Direction of the road
The predefined direction of the road (see 4.2.3) is reflected in the positive and negative offsets in the location
table and in the order of the names of the end points of a road or road segment (see Table 1).
When newly specifying positive directions along roads within pre-defined tables, it is recommended to use
geographic positive directions relative to the co-ordinate system, i.e. on the Northern Hemisphere from south
to north and from west to east.
For ring roads the clockwise travel direction is recommended positive.
In any case it is not allowed to reverse the direction along continuous and / or connecting segments of a
road, e.g. at administrative borders.
4.2.6 Country codes and location table numbers
With ALERT-C, it is assumed that RDS-TMC service and location tables are organised and defined on a
country-by-country basis. Therefore each service and each location table is associated to a country code in
the range 1-15 (hexadecimal 1-F) as described in IEC 62106. A service and the location table it uses shall
have the same country code. There can be more than 1 location table per country. They are distinguished by
an additional location table number in the range 1-63. In non-European countries, the full range of location
tables per country code can be used provided that the Extended Country Code (ECC) is in use and
transmitted (see IEC 62106)
In Europe a different approach is in use for historical reasons, as the ECC is not in use in all countries.
Country codes are shared by more than one country within Europe and the surrounding territories. To avoid
ambiguity in European RDS-TMC location referencing, ranges of location table numbers are allocated to
specific countries, in accordance with the table given in annex B. In this way, each location table is identified
uniquely by its country code and location table number. As can be concluded from annex B, a country like
e.g. Austria can have at most 8 location tables.
4.2.7 Unique location code
The combination of extended country code (8 bits), country code (4 bits) location table number (6 bits) and
location code (16 bits) defines an extended location code, which is unique worldwide.
In Europe the combination of country code (4 bits), location table number (6 bits) and location code (16 bits)
is unique.
4.2.8 Constraints
Constraints on location coding may in future be agreed, modelled and documented. At present, however,
national authorities and/or service providers are free to allocate location codes, as they wish, to locations
specified in accordance with these rules.
4.2.9 Future developments
Within each location table, space (unallocated location codes) shall be left to accommodate future
requirements for additional locations (to deal with new construction, and location referencing requirements
not originally foreseen).
Once a location has been allocated, it cannot easily be re-allocated (in an RDS-TMC/ALERT-C
environment). Therefore, all existing locations and their associated location codes should be regarded as
fixed. However, other attributes of a location may, within certain constraints, sometimes change (e.g. name,
positive offset, negative offset).
Many location table numbers are not yet allocated. The responsible agency in a country can apply for
additional location table numbers in future, to support further applications or more detailed, regional location
tables. New tables can also be issued occasionally to allow for complete updates to existing tables. Such
major changes will however be very disruptive for users, and should be avoided as far as possible or at least
not be done too frequently.
4.3 TMC Location categories, types and subtypes
Location categories, types and location subtypes are standardised, and specified in annex A. Exceptionally,
new subtypes may be proposed to ISO TC204 and CEN TC278 for approval, registration and publication.
Each location is described by a code, which is composed of:
—
a character (A, L or P), indicating the location category (area, linear or point),
— a number indicating the type,
—
a dot,
— a number indicating a subtype.
EXAMPLE 1 P1.8 - roundabout (P = point, P1 = junction)
For types for which not a subtype is defined, the subtype code 0 (zero) has to be used to define the type as a
subtype.
EXAMPLE 2 A3.0 – country
4.4 Location table content
4.4.1 General
The location table content is fixed only for the purposes of definition and exchange. The information used
within specific applications or by individual manufacturers is not fixed, and is not within the scope of these
specifications.
For international consistency, one single location table content shall be adhered to for definition and
exchange purposes. In this structure, some items are mandatory; some items are mandatory where they
exist; and some items are optional.
4.4.2 Nominal record content
The nominal content of each record in the location table is as follows:
— location code,
— code of location (sub) type,
— road/junction number,
— road name,
— first name,
— second name,
— area reference,
— linear reference,
— negative offset,
— positive offset,
— urban,
— intersection reference,
— WGS 84 co-ordinates (longitude and latitude).
Not all of these items shall be present in every record. Table 1 indicates which references are required
and/or allowed, according to location type.
Table 1 — content of location table for ALERT-C
(M) continent - - name (M) - - - - - - - -
country group or
(M) country group - - name (M) - -- - -- -
continent (M)
country group or
Area (M) country - - name (M) - -- - -- -
continent (M)
other area (water
lowest order
area, fuzzy area,
(M) - - name (M) - administrative area-- - -- -
application
or other area (m)
region)
nth order area
(M) - - name (M) - nth order area (M) - - - - - -
(n = 1 to 5)
negative end positive end nth order area or
2 2
(M) road (m) (m) -- --- -
name (M) name (M) country (M)
nth order area or
2 2
-- - -- -
(M) ring road (m) (m) name (O) -
country (M)
nth order area or first order preceding subsequent
nth order segment negative end positive end
2 2
Linear (M) (m) (m) country or other segment, road or nth order nth order -- -
(n = 1, 2) name (M) name (M)
area (O) ring road (M) segment (m) segment (m)
nth order area or
(M) urban street - (M) name (O) name (O) -- - -- -
other area (M)
negative end positive end nth order area or
(M) vehicular link - (m) -- - -- -
name (M) name (M) other area (O)
location code
code of
location
(sub) type
road/ junction
number
road name
first name
second name
area reference
linear
reference
negative offset
positive offset
urban
inter-section
reference
WGS 84 co-
ordinates
road number
lowest order lowest order
junction or name of preceding subsequent
3 3
(M) junction (m) (O) administrative area segment, road or (M) (m) (M)
name (m) intersecting point (m) point (m)
or other area (M) ring road (M)
road (O)
point lowest order lowest order
preceding subsequent
Point (M) intermediate point - - descriptor - administrative area segment, road or (M) - (M)
point (m) point (m)
(M) or other area (M) ring road (M)
lowest order lowest order
other landmark point name preceding subsequent
(M) -- - administrative area segment, road or (M) (O) (M)
point (M) point (m) point (m)
or other area (M) ring road (M)
Table 1 contains an overview of the content of a location table for RDS-TMC. Mandatory fields are shown by (M), while (m) means ,
mandatory where it exists
and (O) means optional. Fields not present are shown by - (dash). The first column is for explanation only. The second column (location code) represents the
key of the table, and therefore has the entry (M) for each record in the table. The sequence of the columns in the table is not significant. Non-empty fields in
the columns area reference, linear reference, negative offset, positive offset contain the code of the location within the same location table to which the field
references. For detailed descriptions of all location types and their codes see annex A.
NOTE 1: Other points include motorway service areas, and prominent landmarks such as named, major bridges and tunnels.
NOTE 2: For roads, ring roads and nth order segments at least one of the two fields road/junction number and road name shall have a value.
NOTE 3: For junctions at least one of the four fields road/junction number, road name, first name and second name shall have a value.
NOTE 4:The column code of location (sub)type in this explanatory table contains descriptions of location types and subtypes. In a real location table this column contains
location (sub)type codes.
location code
code of
location
(sub) type
road/ junction
number
road name
first name
second name
area reference
linear
reference
negative offset
positive offset
urban
inter-section
reference
WGS 84 co-
ordinates
4.4.3 Road descriptions
4.4.3.1 Road numbers and road names
Road descriptions are normally road numbers. They shall be indicated at the highest level of the hierarchy (e.g.
road/ring road) only. In addition to the road number (A1 – R0), a road name (e.g. Autoroute du Nord) or other road
number (e.g. E13 for A1) may be defined. If no road number exists, a road name is mandatory (e.g. Boulevard
Périphérique).
Some segments of a road may carry additional numbers and/or names (e.g. A6 - Autoroute du Soleil, A4 - Kölner
Ring). In the case that a road segment belongs to more than one road this shall lead to multiple entries in the location
table. If the multiple numbers and/or names do not signify the fact that the segment is part of more than one road,
they can be indicated at the segment level in the road-name field, where required. The higher-level road number still
applies.
For vehicular links, the road name can be the name of a company, e.g. Stena Sealink; Eurotunnel; a geographic name,
e.g. Simplon Tunnel, Channel Tunnel; or a marketing name, e.g. Le Shuttle.
4.4.3.2 Junction numbers
For junctions, the field road/junction number is used to describe junction numbers, where they exist.
4.4.4 Names
Names of locations shall normally be given in the language of the locality. However, it is also permissible to
produce versions of location tables with (bi- or multi-lingual) place names translated into other languages.
The junction name may be a description as known by road users.
Negative and positive end-names may be precise (e.g. Dover-Calais), or approximate (e.g. Köln - Frankfurt).
Approximate names refer to nearby places that the road (usually a motorway) does not pass directly through.
Point descriptor for intermediate points is mandatory. Where required, they can be given in terms of
kilometre/milepost references.
4.4.5 Upward references
Two paths shall normally be provided for upward referencing in ALERT-C (see EN ISO 14819-1). The first is for
area references, the second is for linear references. Additional upward referencing paths can be used, but this is
not required as part of the minimum standard for exchange purposes.
Upward references shall normally point to the next defined higher level. For example, a second order area shall
reference a first order area; a first order area shall reference a country; etc.
4.4.6 Offsets
Offsets may be defined for nth order segment locations, and for all types of point locations.
4.4.7 Urban
The values in this column indicate whether the traffic on the point location has a mainly urban character (1) or inter-
urban character (0).
4.4.8 Intersection reference
The intersection reference is a cross reference to a location code, representing the same real world point location,
but related to another road, if the locations are in the same table, or to the same road in another table. If the
location belongs to three or more roads, cross-references are represented in the location table anti-clockwise in a
circular way (see Table 2), such that each location code references only one other location code explicitly, and the
other(s) implicitly. The intersection reference has to include country code and table number if it refers to another
table.
Table 2 — Intersection reference – coding example
Location code Code of location . linear reference . intersection
(sub)type reference
1 L1.1
2 L1.1
3 L1.1
4P1.1 1 5
5P1.1 2 6
6P1.1 3 4
4.4.9 WGS 84 co-ordinates
For each point location the WGS 84 longitude and latitude of the (approximate) centre of the location shall be given
(M), in decimal degrees with 5 microdegrees resolution, with a plus sign (+) for eastern longitude and northern
latitude, and a minus sign (-) for western longitude and southern latitude. Degrees longitude are given in three
digits (with leading zeros if needed), degrees latitude in two digits (with leading zeros if needed) without any
separator between the entire part and the decimal part.
EXAMPLE : +00435455 +5083940 represents 4°.35455 E 50°.83940 N
4.5 Detailed junction referencing
4.5.1 Conventional junctions
Lanes and slip roads are not individually numbered locations in ALERT-C. They are addressed within the structure
of ALERT-C messages (e.g. first exit; second exit; or 'for traffic preceding towards '.)
4.5.2 Complex junctions
In more complex situations where coding of parallel access roads, link roads and slip roads is required, they shall
all be referenced as point locations of the main highway, and shall be coded as separate records in the location
table without positive or negative offset references to other point locations.
4.6 Detailed situation locations
4.6.1 Normal location referencing
In most TMC location tables, locations are pre-defined only at junctions and at other prominent landmarks such as
service areas; prominent, named tunnels and bridges; etc.
Where necessary, the detailed location of an accident shall in future be defined in the message by its distance from
the pre-defined primary location.
Where necessary, the end of the roadworks shall in future be defined in the message by its distance from the TMC
primary location.
Where necessary, the start of the roadworks shall in future be defined in the message by its distance from the end
of the roadworks. Some non ALERT-C protocols like DATEX already allow precise distance indication.
4.6.2 Detailed location referencing
It is permissible to define intermediate points between junctions, at locations specified only in terms of a
kilometre/milepost reference.
Such intermediate points can be used to give more detailed information about the location of an accident, or the
start and end of roadworks, etc.
Intermediate locations can also be used to define traffic monitoring points, e.g. for use in systems where it is proposed
to indicate monitored traffic speeds directly.
4.7 One and two way locations
4.7.1 Basic principles
All TMC locations on two-way roads refer to both directions of travel. It is not permissible to code each direction of
travel separately, unless the carriageways are physically separated to the extent that drivers perceive them as two
separate roads.
4.7.2 Junctions
Junctions are only coded once, not once in each direction. Also, the entry and exit points of slip roads and/or
connecting roads in a junction shall not be separately coded. However, where entry and/or exit points are very
widely separated, it is permissible to code them as separate junctions, if desired. The criterion for deciding whether
to do this shall be: do drivers perceive them as separate junctions? (i.e. are they differently named and/or
numbered?).
4.7.3 Locations having only an exit or entry and locations occurring on one side only
4.7.3.1 General
Some locations only have an exit or an entry, on one or on both sides. Other locations appear only on one side of
the motorway. Examples of the latter are locations like service stations, tunnels, bridges. For such locations the
usage of extra attributes is strongly recommended. An example is presented in Figure 1 and Table 3.
Key
a positive direction
bbridge
c junction J1
d parking
e junction J2
A location
B traffic queue
X accident
Figure 3 — Service area on one carriageway only
4.7.3.2 Using extra attributes for each location code.
The specific possibilities of a point location are described by six extra attributes:
a) In +
Possibility to enter the road in positive direction
(0 = disabled / 1 = enabled)
b) Out +
Possibility to leave the road in positive direction
(0 = disabled / 1 = enabled)
c) In -
Possibility to enter the road in negative direction
(0 = disabled / 1 = enabled)
d) Out -
Possibility to leave the road in negative direction
(0 = disabled / 1 = enabled)
e) Present +
To indicate presence of location in positive direction
(0 = not present / 1 = present)
f) Present -
To indicate presence of location in negative direction
(0 = not present / 1 = present)
-EXAMPLE
Table 3 — The use of extra attributes
loc. code road/ first . neg. pos. . in out in out pre- pre-
Code of loc. junction name . offset offset . + + - - sent sent
(sub) number - + + -
type
4420 P3.2 Bridge . 4456 4423 . 00 0 0 1 1
.. .
4423 P1.3 J1 Junction . 4420 4459 . 11 1 1 1 1
J1 . .
4459 P3.3 Parking . 4423 4460 . 11 0 0 1 0
.. .
4460 P1.3 J2 Junction . 4459 4461 . 11 1 1 1 1
J2 . .
Each point location, independent from its attributes, now is referenced in both directions, using offset (+) and offset
(-). The attributes in +, out +, in -, out -, present + and present - limit the possibilities of the operator to choose
specific offsets on transmitter side.
The major advantage of this method is the opportunity to easily change the referencing at changes of the real
situation without the necessity to update the location tables of all receivers.
Example: if the parking in the example becomes available to traffic on both sides, simply enabling ‘in - and out -' and setting
present - to 1 for location nr. 4459 is sufficient for adapting to the new situation.
The extra attributes may be ignored on the receiver side. The use of 'illegal' combinations of locations and offsets is
not allowed to the operator of the transmitter system, so messages that are broadcasted always are valid.
Annex A
(normative)
TMC Location categorie, types and subtypes
A.1 General
Location categories, location types and location subtypes are standardised, and specified in this annex. New
subtypes can be proposed to CEN/TC 278 for approval, registration and publication. Each location is described by
a code which is composed of:
— a character (A, L or P), indicating the category (area, linear or point),
— a number indicating the type,
— a dot,
— a number indicating a subtype.
Example: P1.8 - roundabout (P = point, P1 = junction).
If no subtype exists in a type, or if no subtype is available for a specific purpose, the number indicating a subtype
should be set to 0 (zero).
EXAMPLE A3.0 - country
A.2 Area locations
Table A.1 — Area locations
Code Type/Subtype Definition
A1.0 Continent One of the seven conventionally recognised, major
geographic unbroken land masses of the world.
E xamples: Europe, Asia, Africa, North America, South
America, Australasia, or Antarctica.
A2.0 Country group Recognised, named set of adjacent countries.
Example 1: Benelux, British Isles, European Union.
NOTE Not all countries belong to country groups. A
country group may belong to another country group.
Generally a country group belongs to one continent.
Example 2: The Benelux belongs to the European Union.
A3.0 Country Administrative area which is a sovereign state,
indivisible from a political point of view, recognised
by a large majority of other countries.
Example: UK, Ireland, France, Germany, Luxembourg,
Switzerland, Serbia, Croatia.
A5.0 Water area Named extent of water about which traffic and travel
messages (e.g. weather information) may be given.
Code Type/Subtype Definition
Subtypes:
A5.1 Sea Named extent of water which is contiguous with the
world's oceans.
Example: North Sea
A5.2 Lake Named extent of water which is physically separated
from the world's oceans.
Example: Lake Geneva
A6.0 Fuzzy area Named extent of land (which is not a subdivision in
the hierarchy below) about which messages may be
given. The boundaries and shape of such areas
need not be precisely defined, i.e. with a margin
which is less than 10% of its size.
Subtypes:
A6.1 Tourist area Area with tourist character.
Example: Lake District; Ardennes
A6.2 Metropolitan area Area with a metropolitan character.
Example: Greater Nottingham
A6.3 Industrial area Area containing a significant concentration of
industrial sites.
A6.4 Traffic area Complex area involving one or more junctions or
intersections between several roads or/and streets.
A6.5 Meteorological area Area about which weather information may be given.
NOTE Not all locations on land need to belong to fuzzy
areas of the above mentioned types. These areas can
partially overlap or can contain one another.
A6.6 Carpool area Dedicated area where motorists can park and meet
for ride-sharing.
A6.7 Park and ride site Dedicated area where motorists can park and take
public transport
A6.8 Car park area Dedicated area where motorists can park.
A7.0 Order 1 area Administrative area which belongs to the first level
administrative subdivision of a Country, but which
may not be the smallest unit in that country.
Example: England within the UK
A8.0 Order 2 area Administrative area which belongs to the second
level administrative subdivision of a Country, but
which may not be the smallest unit in that country.
Example: East Midlands
Code Type/Subtype Definition
A9.0 Order 3 area Administrative area which belongs to the third level
administrative subdivision of a Country, but which
may not be the smallest unit in that country.
Example: Nottinghamshire
Subtypes:
rd
A9.1 Rural order 3 area 3 order administrative area of rural character.
rd
A9.2 Urban order 3 area 3 order administrative area of urban character.
A10.0 Order 4 area Administrative area which belongs to the fourth level
administrative subdivision of a Country, but which
may not be the smallest unit in that country.
Example: Nottingham
A11.0 Order 5 area Administrative area which belongs to the fifth level
administrative subdivision of a country. If defined, the
order 5 area is the lowest level subdivision.
Subdivisions may not overlap or contain one
another, except that any lower order (e.g. 2nd order)
subdivision always refers to a higher order (e.g. 1st
order) subdivision.
The actual definition of 1st, 2nd, 3rd, etc., order
areas is normally based on existing political entities
within each country, and therefore differs from
country to country. Authorities in each country are
responsible for defining these areas.
Not all countries will utilise all levels; e.g. a small
country may only require the first three.
Different numbers of levels may be present in
different parts of a country; e.g. in towns and cities
there may be more levels than in rural areas.
It is also permissible to omit one or more
intermediate levels in some parts of a country. For
example, large provinces may be administratively
subdivided at an intermediate level above towns and
cities, and small provinces not.
A12.0 Application Region Area which is the subdivision of an Administrative
Area of any level or of an Application Area of higher
level.
Example: The subdivision of Scotland into North, Central
and the Borders (South).
A.3 Linear locations
Table A.2 — Linear locations
Code Type/Subtype Definition
L1.0 Road One or more contiguous segments of roadway within
a single national or regional/departmental road
numbering area, bearing a particular national or
regional/departmental road number, whose end
points are in different places.
NOTE 1 Where two or more separate segments of
roadway in a given road numbering area share the same
number, e.g. because an intermediate stretch has yet to be
built, the separated stretches of roadway shall be treated
as the same road.
NOTE 2 A roadway includes both (or all) carriageways of
a divided highway, even if built on physically separate
alignments, and all connecting carriageways in complex
junctions, which are perceived by drivers to share the
same road number.
NOTE 3 European road numbers shall not be used to
define roads except in countries which use these numbers
in place of national numbers, e.g. for motorways.
NOTE4 Roads which coincidentally share the same
regional/departmental number but are located in different
regional or departmental numbering areas of a country
shall not be treated as a single 'road'.
Example 1 : The M1 in Northern Ireland is separate from
the M1 in Great Britain; the D1 in any department of
France is separate from the D1 in another department; etc.
However, the N1 in France is a single road, irrespective of
which department it crosses, because it is numbered at
national level.
NOTE 5 Where a section of road carries more than one
national and/or regional/departmental road number, it shall
be considered part of the lowest numbered road of the
highest category whose number it shares.
Example 2 : If a road is numbered as a motorway and as
an all-purpose road, it shall be treated as part of the
motorway. Or, if a stretch of road has more than one
number of the highest standard which applies to that
section of road (e.g. N1 and N15), it shall be treated as
part of the lowest-numbered road (in this case, N1).
Subtypes:
L1.1 Motorway Road signed with the white overpass across a
divided highway logo on a blue or green background.
L1.2 1st Class Road Example: national road.
Code Type/Subtype Definition
L1.3 2nd Class Road Example: regional road.
L1.4 3rd Class Road Example: other road.
The actual definition of 1st, 2nd, and 3rd Class roads
is normally based on existing classification within
each country, and therefore differs from country to
country. Authorities in each country are responsible
for defining these levels.
L2.0 Ring road Road without end points, forming a continuous ring,
with a single road number and/or name throughout.
NOTE Motorway (or other) rings which do not have a
single number all the way round (e.g. Kölner Ring) shall
not be treated as ring roads. Typically, each side of these
rings has a different number, which is part of a longer,
national highway passing the city tangentially.
Subtypes:
L2.1 Ring motorway Ring road which is a motorway.
L2.2 Other ring road Ring road which is not designated a motorway.
L3.0 Order 1 segment Higher level subdivision of a road/ring road/vehicular
link, which is defined in terms of the locations that it
joins.
L4.0 Order 2 segment Lower level subdivision of a road/ring road/vehicular
link. An Order 2 segment wholly belongs to an Order
1 segment, which is defined in terms of the locations
that it joins.
Not all roads/ring roads (and very few vehicular links)
need be divided into segments; therefore, inclusion
of segments is optional. Where only one level of
subdivision of a road/vehicular link is required, it
shall be considered as O
...




Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...