Point Reference

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.

PointReference attributes

Element

The identifier of the feature being referenced; this will always be the gml:id of a RoadLink.

• Size: 20

• Multiplicity: [1]

ApplicableDirection

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]

AtPosition

Position of the point, expressed as the distance from the start of the linear network element along its curve geometry.

• Type: Length

• Multiplicity: [1]

AtPositionGeometry

The location geometry of the restriction, will be snapped to the RoadLink.

• Type: GM_Point

• Multiplicity: [1]