When a feature in the RAMI specification occurs at a RoadNode a Node Reference will be provided. As a part of the networkRef an element attribute will be given which defines the id of the RoadNode. A location will be provided for Node References which will be the coordinates of the RoadNode the feature references. Finally, a linkReference will contain a reference to the id of the RoadLinks that are affected by the restriction. In most instances, this will be all the RoadLinks that start or end at the referenced RoadNode. However, when a RoadNode has a classification of Grade Separation, then it will only reference the RoadLinks that are at the same level as the feature. An example of this could be at a bridge with a height restriction. The height restriction will only impact the RoadLinks that are passing under the bridge.
The RoadLinks which are travelling over the bridge are not impacted by the height restriction. Therefore, the NodeReference will provide a reference to the RoadLinks which are passing under the bridge and will not reference all RoadLinks which reference the RoadNode through the start or end node references.
The feature types which use a Node Reference are RestrictionForVehicles, Hazard, and Structure.
The identifier of the feature being referenced; this will always be the gml:id of a RoadNode.
Size: 20
Multiplicity: [1]
The co-ordinates for the RoadNode the feature is referencing.
Type: GM_Point
Multiplicity: [1]
A reference to the RoadLink(s) that the feature effects.
Size: 20
Multiplicity: [1..*]
When a feature occurs along a complete single RoadLink, a Link Reference will be used. Geometry is not provided for these features. The direction along the RoadLink for which the feature applies is supplied through the applicableDirection. If the feature applies to the RoadLink, regardless of which direction you travel along it (for example, Traffic Calming), then the value will be both directions. If the feature applies to the RoadLink in a specific direction of travel (for example, a One-Way road), the direction will be given in relation to the digitisation of the RoadLink (the order of coordinates).
The feature types which use a Link Reference are TurnRestriction and Structure.
The identifier of the feature being referenced; this will always be the gml:id of a RoadLink.
Size: 20
Multiplicity: [1]
The direction of the RoadLink to which the reference applies in relation to the direction the link has been captured in.
Size: 21
Type: LinkDirectionValue
Multiplicity: [1]
The Network Reference references the feature back to the network element. The Network Reference has been extended and the feature types which solely use Network Referencing are Maintenance, Reinstatement, Special Designation and Highways Dedication. These features will all reference back to the id of the Street feature: the USRN. Geometry will not be provided. However, where these features do not reference an entire Street feature, and are a partial reference, they will provide a Network Reference Location. This is made up of a locationDescription which provides a textual description of where the feature relates to which will be populated directly from the NSG / SSG.
The feature types which use the Network Reference Location are , , , and .
The name of the attribute and what it is describing.
The nature of the attribute, for example a numeric value or a code list value.
Describes how many times this element is expected to be populated in the data. An attribute may be optional or mandatory within the product. These are denoted by:
‘1’ – there must be a value.
‘0..1’ – population is optional but a maximum of one attribute will be returned These values may be used in combination.
The length of the attribute provided (optional).
The identifier of the feature being referenced; this will always be the gml:id.
Size: 20
Multiplicity: [1]
Textual description of the location extent of the referenced property when the feature partially references the network.
Type: CharacterString
Multiplicity: [1]
Size: 250
The geometry of where the feature starts.
Type: GM_Point
Multiplicity: [0..1]
The geometry of where the feature ends.
Type: GM_Point
Multiplicity: [0..1]
A linear representation of the feature.
Type: GM_MultiCurve
Multiplicity: [0..1]
An area representation of the feature.
Type: GM_MultiSurface
Multiplicity: [0..1]
For a feature that happens at a specific point, that is not coincident with a RoadNode, a Point Reference will be used which will reference a RoadLink. The Point Reference will give the location of the point, defined as a distance value in metres from the start of the RoadLink through the atPosition attribute. In addition, the location of the point will be given by a pair of coordinates which are snapped to the RoadLink, through the atPositionGeometry attribute. Finally, the direction along the RoadLink for which the feature applies is given through the applicableDirection. If the feature applies to the RoadLink regardless of which way you travel along it (for example, a Gate), the value will be both directions. If the feature applies to the RoadLink in a specific direction of travel (for example, an Access Restriction), the direction will be defined in relation to the digitisation of the RoadLink (the order of coordinates).
The feature types which use a Point Reference are AccessRestriction, RestrictionForVehicles, Hazard, and Structure.
The identifier of the feature being referenced; this will always be the gml:id of a RoadLink.
Size: 20
Multiplicity: [1]
The direction of the RoadLink to which the reference applies in relation to the direction the link has been captured in.
Type: LinkDirectionValue
Size: 21
Multiplicity: [1]
Position of the point, expressed as the distance from the start of the linear network element along its curve geometry.
Type: Length
Multiplicity: [1]
The location geometry of the restriction, will be snapped to the RoadLink.
Type: GM_Point
Multiplicity: [1]
For a feature that happens at a specific point, that is not coincident with a RoadNode, a Point Reference will be used which will reference a RoadLink. The Point Reference will give the location of the point, defined as a distance value in metres from the start of the RoadLink through the atPosition attribute. In addition, the location of the point will be given by a pair of coordinates which are snapped to the RoadLink, through the atPositionGeometry attribute. Finally, the direction along the RoadLink for which the feature applies is given through the applicableDirection. If the feature applies to the RoadLink regardless of which way you travel along it (for example, a Gate), the value will be both directions. If the feature applies to the RoadLink in a specific direction of travel (for example, an Access Restriction), the direction will be defined in relation to the digitisation of the RoadLink (the order of coordinates).
The feature types which use a Point Reference are AccessRestriction, RestrictionForVehicles, Hazard, and Structure.
The identifier of the feature being referenced; this will always be the gml:id of a RoadLink.
Size: 20
Multiplicity: [1]
The direction of the RoadLink to which the reference applies in relation to the direction the link has been captured in.
Type: LinkDirectionValue
Size: 21
Multiplicity: [1]
Position of the point, expressed as the distance from the start of the linear network element along its curve geometry.
Type: Length
Multiplicity: [1]
The location geometry of the restriction, will be snapped to the RoadLink.
Type: GM_Point
Multiplicity: [1]
A Multiple Link Reference is the same as a Link Reference, except the feature will contain more than one link reference. This referencing will be used when a feature references multiple, complete RoadLinks, for example a No Turn. The order in which these features apply to the RoadLink is important to ensure the feature is being interpreted correctly and therefore the Link References in the product have been ordered to reflect this. In addition to the order, the direction will be provided in relation to the digitisation of the RoadLink and this is important in interpreting the feature. Geometry will not be provided for these features.
The feature types which use a Multiple Link Reference are TurnRestriction and Hazard.