Situation record¶

A situation may be composed of one or more situation records.

Situation record definition: An identifiable instance of a single record/element within a situation.

This class is abstract.

Each situation record has a unique versioned identifier. This first part of this identifier is established when the situation record is first created in the DATEX II system database. It is completed by a version part. The first part is kept within that system for all its life. The subsequent versions of this situation record must differ by their version part of the identifier. If the situation record is forwarded down a supply chain, each DATEX II system within that chain will assign its own unique identifier to the record when it first creates a corresponding record in its database, but the (compound) identifier created by the original supplier in the chain may optionally be forwarded in the record’s situationRecordCreationReference attribute.

In DATEX Version 3.0, the SituationRecord class and adds the attribute “safetyRelatedMessage” of type Boolean. This attribute indicates, whether the corresponding SituationRecord specifies a safety-related message according to the Commission Delegated Regulation (EU) No 886/2013 with regard to data and procedures for the provision, where possible, of road safety-related minimum universal traffic information free of charge to user. A subset of DATEX II elements, which should be used to meet the requirements of the delegated regulation, can be found in the document “Safety related message sets –Selection of DATEX II Codes, TPEG2-TEC-Causes and TMC-Events for EC high level Categories” from the ITS Directive Working Group.

It is located with one group of locations.

It can have one cause.

It can have one impact on the traffic (when the record type is “TrafficElement” or “OperatorAction”), qualified with:

• Indications on delays (code, value range, value)
• Other details (capacity remaining, effect on lanes, restriction type)..

Source information can be given (country, identifier, name, type, if reliable or not)

A situation record has a validity composed of:

• An validity status which defines if the record has an “active” or “suspended” status, or this status is defined according to periods of time,
• One mandatory global first start time “overallStartTime”,
• One optional global real end time “overallEndTime”,
• One or several validity periods, each having a start date and an end date, for which the situation record is active/valid, detailed with hours/days/weeks/months,
• One or several exception periods, each having a start date and an end date, for which the situation record is not active/valid, detailed with hours/days/weeks/months,
• The optional “overrunning” means the activity/action is still in progress, overrunning its planned duration as indicated in a previous version of the record.

Remarks for forecasts:

• When a record is created, with a start time in the future, it means it is a « forecast » and therefore for traffic elements, probabilityOfOccurrence should never have the value « certain ».
• When this start time arrives, the Supplier should update or end this information if it has not really occurred. If a supplier does not provide updated information at this time a client can not assume that the traffic element is now active, only that it was predicted to be active now.

There are 3 main categories of situation records:

• Traffic element: An event which is not planned by the traffic operator, which is affecting, or has the potential to affect traffic flow (note this does includes events planned by external organisations e.g. exhibitions, sports events etc.).
• Operator action: Actions that a traffic operator can decide to implement to prevent or help correct dangerous or poor driving conditions, including maintenance of the road infrastructure.
• Non-road event information: Information about an event which is not on the road, but which may influence the behaviour of drivers and hence the characteristics of the traffic flow.

These 3 categories are detailed in the following paragraphs.

TrafficElement¶

This class is abstract.

There are 6 kinds of traffic elements:

• Abnormal traffic,
• Activity
• Accident,
• Conditions
• Equipment or system fault,
• Obstruction,

Obstruction

Any stationary or moving obstacle of a physical nature (e.g. obstacles or vehicles from an earlier accident, shed loads on carriageway, rock fall, abnormal or dangerous loads, or animals etc.) which could disrupt or endanger traffic.

This class is abstract.

For each obstruction type, the number of obstructions can be given.

For each obstruction type, details can be given of:

• Mobility type: mobile/stationary,

There are 5 kinds of obstructions:

• Animal presence (alive or not, presence type)
• Environmental obstruction (depth, type),
• Infrastructure damage obstruction (type),
• General obstruction (type),
• Vehicle obstruction (type + individual vehicles characteristics)
• Abnormal traffic: A traffic condition which is not normal.

Details can be given: type, number of vehicles waiting, queue length, relative traffic flow, traffic flow characteristics, traffic trend type.

Accident

Accidents are events in which one or more vehicles lose control and do not recover. They include collisions between vehicle(s) or other road user(s), between vehicle(s) and any obstacle(s), or they result from a vehicle running off the road.

Details can be given:

• cause type,
• accident type,
• overview of people involved (number, injury status, involvement role, type),
• overview of vehicles involved per type (number, status, type, usage),
• details of involved vehicles (type + individual vehicle characteristics)

Equipment or system fault

Equipment or system which is faulty, malfunctioning or not in a fully operational state that may be of interest or concern to road operators and road users. The type of equipment or system and the type of fault must be given.

The type of equipment or system and the type of fault must be given.

Activities

Deliberate human actions external to the traffic stream or roadway which could disrupt traffic. Details must be given in term of: types of authority operations / disturbance / public event, and possibly in term of mobility(mobile/stationary).

Conditions

Any conditions which have the potential to degrade normal driving conditions. A general indicator can be given with 8 possible values “drivingConditionType”:

• impossible,
• very hazardous,
• hazardous,
• passable with care,
• winter conditions (driving conditions are consistent with those expected in winter),
• normal,
• other,
• unknown.

There are 3 conditions categories:

• road surface conditions that are related to the weather which may affect the driving conditions, such as ice, snow or water,
• road surface conditions that are not related to the weather but which may affect driving conditions, such as mud, oil or loose chippings…,
• environment conditions which may be affecting the driving conditions without being directly linked to the road (precipitation, visibility, pollution, temperature, wind)

Operator action¶

For each operator action type, details can be given of:

• Origin: internal / external,
• Status: requested, approved, being implemented, implemented, rejected, termination requested, being terminated,
• Considered action plan

There are 4 kinds of operator actions:

• Roadworks,
• Sign setting,
• Network management,
• Roadside assistance.

Roadworks

Highway maintenance, installation and construction activities that may potentially affect traffic operations.

This class is abstract.

Details can be given of:

• duration,
• scale: major / medium / minor
• under traffic or not,
• urgent or not,
• mobility type: mobile / stationary,
• construction work type: blasting / construction / demolition, road improvement, road widening,
• road maintenance type (e.g. grass cutting, resurfacing, repair, road marking, salting…,
• subject type of works (e.g. bridge, crash barrier, gantry, road tunnel,…,
• information on associated maintenance vehicles

Network management

Changes to the configuration or usability of the road network whether by legal order or by operational decisions. It includes road and lane closures, weight and dimensional restrictions, speed limits, vehicle restrictions, contra-flows and rerouting operations.

There are 6 types of network management:

• Rerouting management (type, itinerary description, sign posted or not,…),
• Speed management (type, speed value),
• Road, carriageway or lane management (type, specified lane or carriageway, minimum number of persons in a vehicle required for HOV/car pool lane),
• Winter driving management (type),
• General instructions to road users (type),
• General network management (type of management and type of person that is manually directing traffic in case of manually directed traffic).

Information on whether the network management instruction or the control resulting from a network management action is advisory or mandatory shall be given.

Other details can be given:

• In which traffic direction the traffic management is applicable,
• For which vehicles the traffic management is applicable,
• If the traffic management instruction has been automatically initiated or not,
• The places (defined in generic terms) where the network management applies (e.g. at toll plaza, in galleries, at high altitude, on slip roads, on the crest of hills),
• Vehicles characteristics for which the network management applies,

Roadside assistance

Details of roadside assistance required.

The roadside assistance type can be given: food delivery, helicopter rescue, vehicle repair …

Service information¶

There are 3 kinds of Service information:

• transit information,
  • Information about other transport means,
  • For example, cancellation, or delay, on a tram, train, plane, etc. journey,
• service disruption (rest area closed, no diesel…),
• road service disruption (no patrol, emergency call out of order …).

ParkingStatusPublication¶

Objectives and utilisation mechanisms

This publication is used to give information on dynamic data of parking sites or groups of parking sites (e.g. free spaces, trends, vehicle count on the parking site …). The publication refers to static information about a parking site or groups of parking sites prior published with the ParkingTablePublication (by using the concept of versioned references).

ParkingTablePublication and ParkingStatusPublication are in accordance with the Commission Delegated Regulation (EU) No 885/2013 about the provision of information services for safe and secure parking places for trucks and commercial vehicles.

Content

The following topics can be covered by this publication:

• Occupancy information for a parking site, a group of parking sites or a group of parking spaces (all declared in the static model and referenced in this publication):
  • Number of spaces (as an override in case of dynamic changes)
  • Number of vacant spaces (as a number, as a ‘higher than’ or ‘lower than’ information as well as in an enumerated form)
  • Number of occupied spaces (as a number, in enumerated form as well as in trend form)
  • Number of parking vehicles
• Information on individual parking spaces (occupied or free, temporary closed)
• Overriding thresholds: It is possible to override the static threshold information, i.e. the defined fill grades of a parking site for which the dynamic status information should change between different states (incl. overcrowding states)
• Status information: A state information on the fill grade of a parking site incl. overcrowding information (in limited form also for a group of parking sites)
• Validity of parking space- and group of parking space-declarations: Spaces might be temporary closed or defined for mixed usage (i.e. declaration not valid all the time).
• Information about the availability of additional equipment or additional service facilities (overriding the amount, current availability, opening and vacancy information).
• Fill- and exit rates (sensor data, which can be based on a static MeasurementSiteTable information)
• Vehicle count within interval, i.e. incoming or outgoing vehicles or change of occupancy within time

By defining the validity of the dynamic information, it is possible to publish real time data, historical data or forecasts. It is also possible to publish series over time.

ParkingTablePublication¶

Objectives and utilisation mechanisms

This publication is used to publish static information of parking sites or groups of parking sites. This comprises urban or interurban parking sites as well as special facility and (secure) truck parking information. It covers on street parking as well as off street parking (car parks, parking places, motorway parking areas …). Within a parking site, information can be specified down to groups of parking spaces or even for individual parking spaces. There are four minor Level B extensions entailed in this publication:

• Area is extended to specify a polygonal area
• Point is extended to specify junctions
• Period is extended to specify special days and holidays
• VehicleCharacteristics is extended to specify additional vehicle types, loads and emission information

The static information forms the base for dynamic occupancy information, for which you should use the ParkingStatusPublication.

ParkingTablePublication and ParkingStatusPublication are in accordance with the Commission Delegated Regulation (EU) No 885/2013 about the provision of information services for safe and secure parking places for trucks and commercial vehicles.

Content

Because of the size of this publication, it is not described on attribute level here. The description is focussed on included subjects instead:

• For parking sites, groups of parking spaces or individual parking spaces the following assignments can be specified as convenient, as allowed or as not allowed:
  • Specified type(s) of users
  • Specified type(s) of vehicles (incl. hazardous materials)
  • Time (for mixed usage of parking spaces, for example day usage for cars, night usage for lorries).
• Basic information (number of spaces, reservation information, short or long term parking, …), each also possible for individual groups of parking spaces (i.e. for example it is possible to specify the possibility of reservation just for a part of the parking site or to specify the number of parking spaces for lorries).
• Special Permits for users or vehicles (e.g. disabled permit, government permit)
• Permitted or prohibited actions on the parking site (e.g. smoking, camping)
• Contact information (address, telephone number etc.) for the parking site as well as for several other stakeholders or services (e.g. owner, reservation service, …)
• Entrances and exits with characteristics and geo-reference
• Opening times, expressed by the detailed validity model
• Additional equipment and additional service facilities (long list of items, like for example toilets, internet, restaurants, police station) optional each with opening times, tariffs, location, validity or restriction to users or vehicles
• Electric charging stations (incl. technical parameters and connector types)
• Information on the LABEL-categorisation and on security measures
• Tariff information in a complex structure, for different charge bands, depending on user or vehicle type and for different seasons (incl. different types and modes of payment, payment cards and reservation fees)
• Thresholds, i.e. defined fill grades of a parking site for which the dynamic status information should change between different states (incl. overcrowding states)
• Parking Routes incl. geo-reference, direction and colour information
• A colour mapping to occupancy states
• Parking scenario (truck parking, rest area, car sharing, mechanical drop off, …)
• Geo-reference information (all methods which are available in DATEX) for all elements

The following two pictures show information on assignments, dimensions and Geo-referencing, which can be specified with the Parking Table Publication:

ParkingVehiclesPublication¶

Objectives and utilisation mechanisms

The ParkingVehiclesPublication allows specifying information on specific parking vehicles. The publication refers to static information about a parking site or groups of parking sites prior published with the ParkingTablePublication (by using the concept of versioned references).

Content

For a parking vehicle, the following information can be specified:

• Reference to the parking space used
• The parking period
• The parking permit
• Information about the vehicle, like licence plate information or vehicle characteristics
• Information on the individual charge, including the paid amount or the method of payment

The process of parking must not yet be finished; it is possible to omit the end of the parking period.

ElaboratedDataPublication¶

Objectives and utilisation mechanisms

This publication is used to give information that is in some way elaborated or derived. Typically, this is data which has been elaborated by a traffic centre from input data held in its database.

Content

This publication contains one or more elaborated data sets.

With this publication, attributes can be given in the InformationHeader class which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

A set of default values for “forecast”, “period” and “time” can be provided to clients which are applicable throughout the publication if no others are provided at the detailed level. This helps in minimising the size of publications where large numbers of values are sent which share common parameters.

Also to assist in minimising the volume of required values to be sent for traffic status covering wide expanses of a road network, ReferenceSettings can be provided to a client. ReferenceSettings comprise a reference to a predefined set of non-ordered locations (see Predefined Locations publication) and a default value that can be assumed by a client for the traffic status at all these locations if none is received. Thus a supplier only needs to send for those locations the actual values of traffic status which deviate from this default value.

Source information can be given (country, identifier, name, type, reliable) for each elaborated data.

A validity can also be given (as for situation records) composed of:

• An validity status which defines if the record has an “active” status or this status is defined according to periods of time (one can consider the third possible value “suspended” is not applicable for this kind of data element).
• One mandatory global first start time “overallStartTime”
• One optional global real end time “overallEndTime”
• Several periods, each having a start date and an end date, for which the elaborated data is active/valid, detailed with hours/days/weeks/months
• Exception periods, each having a start date and an end date, for which the elaborated data is not active/valid, detailed with hours/days/weeks/months.

The optional “overrunning” is not applicable for this kind of data element.

It can be indicated if the elaborated data is a forecast.

In case of fault when elaborating this data, it is possible to specify the type of fault (intermittent data values, no data available, spurious unreliable data values, unknown fault or other).

Each elaborated data item comprises a Basic Data value.

MeasuredDataPublication¶

Objectives and utilisation mechanisms

This publication is used to give measured data which has been derived from equipment at specific measurement sites, where each site is identified by reference to an entry in a predefined measurement site table.

Content

This publication contains measurements from one or more sites.

With this publication, attributes can be given in the InformationHeader which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

The measured data publication must contain a reference to the measurement site table used.

Each set of site measurement values must always contain a reference to the measurement site and a measurementTimeDefault which is the default time for each measured value if no other time is specified for an individual measurement.

Each set of site measurements has an ordered (indexed) list of measured values, where the order (index) corresponds with the measurement definition order (index) in the Measured Site table. So there is no need for any further identification for each measured value. The values that are measured are referenced by the index in the ordered list of values for that site.

A measured value can identify the type of measurement equipment used.

A measured value can also have a Location characteristics override. This is used to override the predefined lanes attribute and to indicate a reversal of flow compared with that was defined in the Measurement Site table.

In case of fault when measuring this data, it is possible to specify the type of fault (intermittent data values, no data available, spurious unreliable data values, unknown fault or other).

Each measured value comprises a Basic data value.

However the following points are of note for its use in the Measured Data publication:

• The point at which the measurement equipment is located (i.e. the site) is defined in the appropriate entry in the Measurement Site table. However, if the measurement relates to a section of road or a location (e.g. ANPR which determines measurements over a stretch of road) this can also be provided in the “pertinentLocation” which is an aggregation associated with the BasicData.
• TrafficStatus and TravelTimeData are normally provided as Elaborated data, but may be provided as Measured data if appropriate (e.g. because values are provided by an outstation).

Basic Data¶

Basic data value is a general abstract class which has the following attributes:

• Time precision, precision to which time of calculation or measurement is given
• Period (in seconds)
• Time, the time when basic data value was measured or elaborated.

Each Basic Data value can have a pertinent location. (see “location” paragraph). Generally, this location is identified by reference; see the paragraph concerning predefined locations.

Basic Data values are of one of the following types:

• Travel Time data
• Traffic Status
• Traffic data
• Weather data

The following paragraphs describe each of these basic data types:

Travel Time data

It has the following specific attributes:

• Travel time trend type: decreasing, increasing, stable
• Travel time type: best, estimated, instantaneous, reconstituted
• Vehicle type for this travel time.

It may be also associated with:

• Travel time (in seconds)
• Free flow travel time
• Normally expected travel time, as well as
• Free flow speed

Traffic Status

It has the following specific attribute:

• Traffic trend type: traffic building up, traffic easing, traffic stable, unknown.

and can be associated with

• Traffic status value: Impossible, congested, heavy, free flow, unknown if it differs from the reference value given for the publication

Traffic data

This value is usually sent as Measured Data, but may also be sent as Elaborated Data.

Traffic values can be classified on the basis of Vehicle characteristics.

There are 5 kinds of traffic values:

• Traffic headway
• Traffic flow
• Traffic speed
• Traffic concentration
• Individual vehicle measurements (not applicable for elaborated data).

Weather data

This value is (usually sent as Measured Data, but may also be sent as Elaborated Data).

There are 7 types of weather values:

• Precipitation information,
• Wind information,
• Temperature information,
• Pollution information,
• Road surface condition information,
• Visibility information,
• Humidity information.

However, the following point is of note for its use in the Elaborated Data publication:

• Traffic values and weather values are normally provided as Measured data, but may be provided as Elaborated data if appropriate (e.g. because values are provided by calculation).

MeasurementSiteTablePublication¶

Objectives and utilisation mechanisms

The Measurement Site Table publication is used to provide information relating to predefined measurement sites and the measurements that can be made at those sites. The sites and the details of their measurement characteristics are seen as static or quasi static (i.e. they seldom change).

The measurement site details and their measurement characteristics are referenced by Measured Data publications which enable these publications to be efficient when large volumes of measured data values need to be conveyed.

Content

This publication contains one or more measurement site tables.

With this publication, attributes can be given in the InformationHeader which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

The Measurement Site table has a unique versioned identifier.

The Measurement Site table has a list of Measurement site records, each corresponding to a single measurement site. Every Measurement site record has a unique versioned identifier and the following attributes:

• Computation method,
• Measurement equipment reference,
• Measurement equipment type used,
• Measurement site name,
• Measurement site number of lanes,
• Measurement site identification,
• Measurement side,
• Measurement site record version and time.

The Measurement site record always has a single location.

Every site record must also have an ordered list of Measurement specific characteristics. This ordered (indexed) list of characteristics relates to the types of measurements that can be made at that measurement site. The ordering is significant because this order (indexing) is used in the Measured Data publications to distinguish between the different measurements received from the referenced site.

Measurement specific characteristics contains information about:

• Accuracy
• Period
• Smoothing factor
• Specific lane
• Specific measurement value type.
• Specific vehicle characteristics

These values are seen as static for the particular measurement at the site and do not have to be repeated for each measured value in the Measured data publication, unless they need to be overridden in particular cases (see Measured data publication section).

VmsPublication¶

Objectives and utilisation mechanisms

This publication is used to give information on the current status and settings of one or more variable message signs (VMS) units, each unit controlling one or more individual variable message signs.

Content

This publication contains one or more VMS units.

With this publication, attributes can be given in the InformationHeader class which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

Each VMS unit must always contain a reference to a versioned VMS Unit table and a reference to a versioned VMS unit record in this VMS Unit table which defines the characteristics of the VMS unit.

A VMS unit may control one or more variable message signs on a single gantry or on different gantries.

The VMS class provides the current status and settings of the VMS and the currently displayed information. Where a VMS is displaying a sequence or alternating set of messages these are ordered according to the messageIndex qualifier. Each VMS associated with a VMS unit is referenced by its vmsIndex. The vmsIndex also provides a reference to the specific VmsCharacteristics (defined in the VmsUnitTablePublication) that are relevant for the VMS which is controlled by the referenced VMS unit.

To assist in minimising the volume of required values to be sent for VMS messages covering wide expanses of a road network, characteristics of VMS and VMS units can be provided to a client using the VmsTablePublication.

In case of fault of VMS site or of VMS, it is possible to specify the type of fault (communication failure, power failure, out of service, incorrect message or pictogram display, unable to clear down, unknown fault or other).

A VMS is composed of:

• A general item if the VMS is working and about message sequencing interval in seconds, if applicable.
• The Text Display Area Settings (text lanterns, text luminance level, and luminance override).
• An ordered set of Pictogram Display Area Settings, one for each display area (picto lantern, picto luminance, …). Each pictogram display area on a VMS is referenced by its “pictogramDisplayAreaIndex” and details of its position relative to the text or its absolute position may be provided in VmsPictogramDisplayCharacteristics.
• An ordered set of VmsMessages. The messageIndex provides the ordering of a sequence of displayable messages. The VMS is displaying each message in turn according to its messageindex “order”. The sequence of messages displayed is continuously cycling.

In case a VMS is not defined previously in a VmsTablePublication, its static characteristics must be provided about:

• Its location in term of position (vmsLocation – practically defined with a point) and in term of managed logical location i.e. the road section (defined as a location reference) where the VMS is applicable.
• Its physical characteristics with VMS text display characteristics and VMS pictogram display characteristics. As a VMS may have several pictogram areas, every one is referenced by its pictogramDisplayAreaIndex. Every area may be completed by VMS supplementary panel characteristics.

These latter classes are defined more in details in the subsequent VMS table publication. Each elaborated data item comprises a Basic Data value.

Every VMS message comprises several elements. The adopted modelling takes into account different types of messages, with or without displayed text of several lines (in sequence), with or without pictogram display, each pictogram can have a VMS supplementary panel. The general information includes:

• VMS message information type (situation warning, travel time, traffic management, date and time, temperature, campaign message, instruction, future information).
• Time, the time when message was lst set
• Coded reason for setting (situation, campaign, operator created, traffic management, travel time or default) and the associated management or diversion plan.
• The authority, organisation or system which requested the setting of the message and the one which set it.
• References towards the related situations and situation records for which the message is related.
• Distance of the VMS from the location of the related situation record/element

A VMS message includes:

• One or several text pages. Where multiple pages of text are defined each is referenced by its “pageNumber” and is displayed sequentially according to the “pageNumber” order in the same display area.
• Each VMS text page comprises one or several lines of text. Where multiple lines of text are defined each is referenced by its “lineIndex” qualifier and is ordered accordingly. The VMS text line is also defined by the text itself, its colour, the used language, if it is flashing or not.
• One or several VMS pictogram display areas. Each pictogram display area on a VMS is referenced by its “pictogramDisplayAreaIndex” and details of its position relative to the text or its absolute position may be provided in VmsPictogramDisplayCharacteristics.
• Each VMS pictogram display area may display one pictogram or a sequence of pictograms. The order of sequencing of the pictograms is defined by the “pictogramSequenceIndex” values.
• Each VMS pictogram can be defined by one or several pictogram description, a code, the value of distance,, length, weight or width to be displayed on the pictogram, if the pictogram is in inverse colour or if there is presence or red triangle or not, if it is compliant with the Vienna convention on road signs and signals, …
• A pictogram can be supplemented by one VMS supplementary panel which consists in one VMS text line (see above for description)

VmsTablePublication¶

Objectives and utilisation mechanisms

The VMS Table publication is a publication containing one or more VMS Unit Tables each comprising a set of records which hold details of VMS units. The VMS sites and the details of their characteristics are seen as static or quasi static (i.e. they seldom change).

The VMS tables and their VMS unit characteristics are referenced by VMS publications which enable these publications to be efficient when large volumes of displayed messages need to be conveyed.

Content

This publication contains one or more VMS unit tables.

With this publication, attributes can be given in the InformationHeader which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

The VMS unit table has a unique versioned identifier.

The VMS unit table has a list of VMS unit records, each corresponding to a single VMS unit (entity managing one or several physical VMSs).

Every VMS unit record has a unique versioned identifier and the following attributes:

• Number of VMS,
• VMS unit identifier,
• VMS unit electronic address,
• VMS unit IP address,

Every VMS unit record must also have an ordered list of VMS records containing the physical characteristics and the location of each VMS. This ordered (indexed) list of these characteristics relates to different display areas on the VMS. The ordering is significant because this order (indexing) is used in the VMS publications to distinguish between the different display areas.

The VMS record can have until two location references. The first one gives the physical VMS location in term of position (vmsLocation – practically defined with a point) location references and the second one gives its managed logical location i.e. the road section (defined as a location reference – practically defined with one or several linears) where the VMS is applicable.

The VMS record also contains global information about:

• VMS type (colour graphic, monochrome graphic, continuous sign, matrix sign, other)
• Number of pictogram display areas
• VMS description
• VMS display height and width, its height above roadway
• VMS physical mounting (gantry, central reservation, roadside and roadside cantilever, overhead bridge, tunnel entrance, trailer and vehicle)
• VMS owner
• VMS type code.
• If its display areas are dynamically configurable.

It can also contain information for the VMS text display characteristics:

• Maximum font height, width and spacing
• Maximum numbers of characters, rows and sequential pages
• Maximum text luminance level
• Minimum font height, width and spacing
• Text display height and width
• Text lanterns presence
• Text page sequencing capability
• Number of text pixels across and down
• Text position absolute (on left, on right, at top, at bottom) and coordinates (X & Y) in metres
• Legend code list identifier

As well as for each VMS pictogram display characteristics through its “pictogramDisplayAreaIndex”, details of its position relative to the text or its absolute position may be provided like:

• Maximum number of sequential pictograms
• Pictogram display height and width
• Pictogram number of colours
• Maximum pictogram luminance level
• Pictogram lanterns presence
• Pictogram sequencing capability
• Number of pictogram pixels across and down
• Pictogram position absolute (on left, on right, at top, at bottom), relative to text (above, below, to the left, to the right) and coordinates (X & Y) in metres
• Pictogram code list identifier

These values are seen as static for the particular VMS and do not have to be repeated for each displayed message in the VMS publication, unless they need to be overridden in particular cases (see VMS publication section).

Point location¶

Several location referencing systems can be used. At least one must be present:

• Point by coordinates (ETRS89): latitude, longitude plus optional bearing
  • Warning: Coordinates are defined according to the European Terrestrial Reference System 1989 (ETRS89) which was coincident with ITRS in 1989. This is the European implementation of ITRS, but unlike ITRS and WGS84 it is centred on Europe. ETRS89 is the EU-recommended frame of reference for geodata in Europe.
• Point along linear element:
  • linear referencing system based on referents, distances to referents all of them being along a linear element (road element). Details (road name, direction, height, …) may also be added.
• TPEG Point Location: a TPEG point location has direction (e.g. northbound, eastbound, clockwise …) and is either specified as:
  • a simple point on the road network either at a junction or not, or
  • a framed point on the road network between two other points (i.e. framing points) on the road network.

• ALERT-C Point : country code, table number and version, plus:
  • Mandatory code and ALERT-C direction and optional name (Method 2); or
  • Same elements plus offset distance (Method 4)
• OpenLR Point

Linear Referencing¶

Several linear location referencing systems can be used. At least one must be present:

• Single Road linear element
  • Linear within linear element location: besides details common with the point along linear element, it includes:
    • A linearly referenced point identifying the “from” point and another linearly referenced point identifying the “to” point, where the “to” point is downstream from the “from” point according to the direction provided by the underlying linear road element
  • ALERT-C linear : country code, table number and version, plus:
    • Mandatory linear location code and ALERT-C direction and optional name (method linear by code) or
    • Mandatory primary code, secondary code and ALERT-C direction and optional names (Method 2), plus offset distances (Method 4)
  • TPEG Linear Location
    • A TPEG point location identifying the “from” point and another TPEG point location identifying the “to” point, where the “to” point is downstream from the from” point according to the direction of traffic flow.
    • A direction (e.g. northbound, eastbound, clockwise …)
  • OpenLR Linear
  • GmlLineString

Any Linear Location must have an instance of at least one of these classes. If using multiple instances, producers must take care to ensure they represent the same location.

Moreover, supplementary descriptions can be added to the linear location: length, position on the carriageway, position descriptor (at rest area, in tunnel…), etc.

Area location¶

Several location referencing systems can be used. At least one must be present:

• ALERT-C area: country code, table number and version, plus:
  • Mandatory area location code and optional name
• TPEG Area Location, a TPEG area has a type of either “largeArea” or “other” and optional height information and height type (e.g. above sea level…). It is further specified either as:
  • A “named only” area (i.e. by a name and a descriptor type, e.g. county name, town name…) or
  • A geometric area comprising a centre point (defined by ETRS89 latitude and longitude), a radius and an optional “named area”.
• namedArea
• GmlMultiPoygon
• OpenLR Area

At least one of these aggregated classes must be present. If using multiple instances, producers must take care to ensure they represent the same location.

ALERT-C location referencing system¶

This section describes the ALERT-C referencing system and gives details of the contents of ALERT-C tables. Since this version of the DATEX II specification does not include the exchange of ALERT-C Location tables this is provided as general support information.

Only the reference is transmitted between the Supplier and the Client. It is up to the client to look it up in the table for the descriptive elements corresponding to the referenced location using the ALERT-C code. To have a unique ALERT-C coding at the European level, the reference must comprise three elements (triplet):

• Country Code,
• Table number,
• Location number

Two distinct locations at the European level cannot have the same triplet.

It is the European standard EN ISO 14819-3 that defines the rules of constitution of the ALERT-C location tables.

The following table gives indications on the contents of the various common attributes used by the classes related to the ALERT-C location.

Examples can be found here.

Gml¶

The package “Gml” includes four class with their attributes for the definition of a linear location which specializes a location of a traffic object. This method complies with EN ISO 19136.

Linear referencing system of locations¶

This section describes the linear referencing system used by DATEX II. It accommodates all the actual linear referencing systems adopted by road operators in Europe. It can be used for systems based on a distance measured from the linear element origin: kilometre point or its US equivalent mile point or true mileage as well as for the UK system named “chainage”, hectometre-points, or link offset. It also accommodates systems where there exist intermediate points from which the distance is measured: systems based on kilometre-post, milepost, reference post as well as cross-streets or control sections. It is fully compliant with a draft CEN ISO standard on the same topic (EN ISO 19148) being adopted, with the two following restrictions:

• Distances are only expressed in metres according to the DATEX II principle on units, unlike the draft standard where it is permissible to express them with different units.
• The lateral/vertical offset features are not implemented

Reminder: This system is based on predefined elements that need to exchanged and agreed by the Supplier and the Client before being used in a DATEX II exchange. Only the reference is transmitted between the Supplier and the Client. It is up to the client to look up the descriptive elements corresponding to the referenced location using the provided elements.

Such a linear referencing system includes three elements:

• general information on the location itself:
  • administrative area including the location,
  • geographic direction: e.g.: northbound, westbound, clockwise, …
  • relative traffic flow direction of the considered location regarding the underlying
  • referenced linear element direction: aligned, opposite, both, unknown
  • height grade of linear section: above grade, at-grade, below grade
• Expression of distance of the referenced point: this expression of distance can be absolute (expressed from the origin of the road element), relative to an upstream intermediate point named “from referent”, or interpolative (expressed by a percentage along the linear element and calculated from the linear element origin).

In case of relative method, the “from referent” may also be associated with a “toward referent” (downstream), both bracketing the considered point.

In case the considered point is bracketed by two referents, the direction defined as going from the “from referent” to the “toward referent” overrides the general direction of the linear element (see below). The location direction is thus compared to this direction.

A referent is typified: boundary, intersection, reference marker, landmark, road node.

Finally, each referent may be associated with ETRS89 geographic coordinates (latitude, longitude).

• The linear element underlying the location. It includes several attributes:
  • road number,
  • road name, one of the two attributes shall be provided,
  • linear element nature (optional): road, road section, slip-road, other
  • reference model which identifies the road network reference model which segments the road network according to specific business rules. It may be e.g. a graph describing the considered road network.
  • reference model version: version of the referenced road network model

This underlying linear element is defined either with an identifier string (e.g. looking up in a map database) or as an ordered sequence of points with one at each extremity. These points are defined as referent. In this latter case, the sequence order provides the reference linear element direction.

OpenLR¶

OpenLR point location references are defined in more detail in the OpenLR whitepaper version 1.5.

PointCoordinates¶

SupplementaryPositionalDescription¶

TpegLoc¶

NamedArea¶

Objectives and utilisation mechanisms¶

This publication is used to predefine (sets of) locations which can then be referred to in any of the other publications by means of a single versioned reference attribute. This allows great simplification of those publications where repeating static or quasi-static locations are used.

A set of locations defined as a container may contain one location or can be characterised as an Itinerary (ordered set of locations) or as a group of non-ordered locations. Predefined itineraries as well as a group of non-ordered locations contain several predefined locations. Each predefined location may be of any type, i.e. point, linear or area. Obviously an itinerary cannot include area-typed locations. Each set of predefined locations and each individual predefined location have its own unique versioned identifier and can be referenced in other publications.

The main utilisation is when publications are sent periodically and always concern the same locations, which are mostly itineraries or elementary linear locations (for instance, elaborated data and traffic views publications).

The utilisation mechanism is as follows:

• Step 1: the DATEX II client gets a predefined location publication with the locations identifiers and definitions,
• Step 2: when the DATEX II Supplier delivers publications to this client, it only uses the predefined location identifiers and the client is able to look up the identifier and obtain the real location details.

The advantage of this mechanism is to reduce the publication size.

When a predefined location set is modified, the DATEX II Supplier has to inform the concerned DATEX II Clients.

Content¶

With this publication, attributes can be given in the InformationHeader which provide clients with information management details (area of interest, confidentiality, information status, urgency) relating to this publication.

The predefined location container (abstract) shall be derived into a predefined itinerary, a predefined group of non-ordered locations or simply a predefined location. All three have a unique versioned identifier and may have a name.

Itinerary and group of non-ordered locations are made up of predefined locations; each location has its own unique versioned identifier and may have its own name.

The definition of each predefined location uses the same location definition as the other publications. When predefining these locations, usage of other references is not allowed when it infers circular references.