ORRoadNode_GUID_RoadLink_TOID_13

This document aims to provide all the information to evaluate if the method of associating the respective identifiers is suitable for your needs. These identifier relationships have been extracted from existing premium products and are presented in a standalone table for easy and open access to the information. It describes which product the information was extracted from, what information was extracted and how the source product derived the original association between the identifiers.

Identifiers displayed on OS Map data showing RoadLink and Topographic area feature types

Relationship Extraction

This relationship is between the non-persistent unique identifier (GUID) of the RoadNode features in OS Open Roads and the Topographic Identifier (TOID) of RoadLink features in OS MasterMap Highways Network, which represent the same feature.

The relationship is extracted from the OS Open Roads Lookup table which is supplied with the OS Master Map Highways Network – Roads. This table provides the TOID of the RoadLink feature in the OS MasterMap Highways Network and the GUID of the ORRoadNode feature in OS Open Roads which represent the same feature in OS Open Roads. This will be used where a RoadLink in OS MasterMap Highways has been simplified in the OS Open Roads product to an ORRoadNode (for example, a collapsed roundabout).

Correlation Method

This relationship is determined using the OS Open Roads Lookup table which is supplied with the OS Master Map Highways Network – Roads. This table provides the TOID of the RoadLink feature in the OS MasterMap Highways Network and the GUID of the ORRoadNode feature in OS Open Roads which represent the same feature in OS Open Roads. This relationship is created by Ordnance Survey using a spatial match between the point and line features.

The two source products for these identifiers are on different refresh cycles. OS MasterMap Highways Network - Roads is updated monthly, whereas OS Open Roads is updated every six months. Therefore, some of the version information in the product may have changed and mean that the relationship is out of sync.

A Confidence Value is assigned to indicate the reliability of the version information provided in this product in relation to the version of the features used to form the correlation in the original product. The Confidence Value is given for each relationship, which is defined in this relationship as:

Confidence Value	Definition
Version information is correct	The version information provided is the same as the version of the feature used to create the correlation.
Version information has changed	The version information provided is different from the version of the feature used to create the correlation.