RoadLink_TOID_TopographicArea_TOID_2

This page 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 Topographic Identifier (TOID) of the RoadLink features in OS MasterMap Highways Network and the TOID of the TopographicArea of the corresponding road surface area in OS MasterMap Topography Layer.

The relationship is extracted from the relatedRoadArea attribute on the RoadLink features in OS MasterMap Highways Network - Roads product following its release.

Correlation Method

This relationship is determined by a line in a polygon intersection between the RoadLink centre line geometry and the TopographicArea polygon(s). Specifications of capture can vary between the two source products, therefore not every RoadLink in OS MasterMap Highways Network will be represented by a TopographicArea. The relationship is performed by Ordnance Survey while creating the OS MasterMap Highways Network – Roads product.

The two source products for these identifiers are on different refresh cycles. OS MasterMap Highways Network - Roads is updated monthly, whereas OS MasterMap Topography Layer is updated every six weeks. 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 potentially changed	The version information could be different from the version of the feature that was 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.