Structure

The Road Network is a topologically structured link and node network made up of the following feature types:

Roads feature types

Feature type	Description
RoadLink	A line segment representing the general alignment of the carriageway of the road.
RoadNode	A point connecting to at least one RoadLink, providing network connectivity.
Road	A Road defines the complete collection of references to RoadLink features defining the network topology which share the same road name and/or road classification number. For example, the A38 or Romsey Road.
Street	A Street feature is the definition of the street as defined in the National or Scottish Street Gazetteer, made up of aggregated geometry with a unique identifier (USRN).
RoadJunction	A collection of RoadNodes that make up a named or numbered road junction.
FerryLink	A feature which represents a ferry route between two FerryNodes.
FerryNode	A feature representing the point at which a vehicle ferry route or section of ferry route starts or ends.
FerryTerminal	A feature representing the point at which vehicle transfers from the ferry network to the road network or vice versa.

Relationships between Road Network feature types

OS MasterMap Highways Network has been built with the INSPIRE Transport Networks Data Specification as a basis. This has been extended to include the additional properties required by BS 7666-1:2006, defined within the NSG to ensure that conformance to both INSPIRE and BS7666-1:2006 can be achieved.

Common attribution

Each feature within the OS MasterMap Highways Network will have the following common attribution:

• gml:id, gml:identifier and inspireId

• beginLifespanVersion

• inNetwork – this shall always be set to “OSHighwayNetwork”

• reasonForChange

• validFrom

This is assigned a nilReason value “unknown” for most features.

In addition, many of the attributes which have been inherited from the INSPIRE Transport Network model have a stereotype of ‘voidable’, for example “beginLifespanVersion”. Where these attributes have not been populated there is a requirement to give a reason for this. This will be specified in the GML through an attribute called “nilReason”.