OSM and OSL differences analysis

The OSM and OSL differences analysis ( http://www.itoworld.com/product/data/osm_analysis/) by ITO World provides various road name completeness measuring statistics for England, Wales and Scotland by comparing road names in OpenStreetMap with those released by the Ordnance Survey in their OS Locator dataset. These are broken down by district/borough and thematic and trend and slippery map views.

Functionality

The service allows these 408 districts/boroughs to be ranked in order of road name completeness, and highlights differences between then two datasets visually on a slippery map. A coloured thematic map view is also available and a summary page for each district/borough. The OSM and OSL differences tileset used by this service is also available separately and can be accessed from within the Potlatch and JOSM editors.

Street name differences of a single apostrophe are classed as minor errors in the summary page and shown in grey on the map tiles.

Tagging within OpenStreetMap

Errors and omissions in OpenStreetMap should be corrected by adding new roads or correcting names in the usual way.

If OS Locator provides a valid alternative name for a road then this name should be added to alt_name=*.

If the wrong name is given within the OS Locator product for an existing road then this should be tagged using not:name=* tag and optionally also the not:name:note=* to provide further information. This check will then stop flagging this as a mismatch, but list it on the district/borough summary page as a mistake in the OS data. The Ordnance Survey are aware of this service and can use it as part of these data quality feedback mechanism.

If a name is given in OS Locator for a street that doesn't exist or no longer exists then an invisible 'road' can be added to OpenStreetMap using highway=no to contain the relevant not:name=* and not:name:note=*.

History

The service was introduced in July 2010 with an an announcement on the ITO World blog.