On 13/08/2020 11:25, Robert Whittaker (OSM lists) wrote:
On Wed, 12 Aug 2020 at 16:56, SK53 <[email protected]> wrote:
OpenRoads from the Ordnance Survey contains a field containing the toid for the
street name. I wonder if we should include these alongside usrn & uprn. They
may be more useful than either for gathering complex roads which share a name.
I'd tend to see the TOIDs are just an internal ID used in OS MasterMap
and not something that there's much value in adding to OSM. I'd have
thought that that USRN should be a sufficient unique reference number
for highways. (Everything in OS MasterMap has a TOID, and actually I
think streets have two -- one for the centreline geometry, and one for
the bounding polygon. If we start adding TOIDs for streets, where
would we stop?)
A street will have multiple TOIDs if it has multiple names. For example,
USRN 200001, part of the A27 Shoreham By-Pass, is linked to TOIDs
osgb4000000023625257 and osgb4000000030480763 - the first for the
number,m the second for the name.
However, from a practical point of view, if you want to check OSM for
completeness against OS Open Roads, then having the TOID in OSM would
be useful. But perhaps a better solution would be to persuade OS that
they should be including the USRNs in OS Open Roads -- as these are
now the promoted 'gold standard' open unique identifiers for streets.
There's an Open Data Linked Identifiers (LIDS) dataset available from OS
which links USRNs to TOIDs.
https://osdatahub.os.uk/downloads/open/LIDS
Well, actually, there's two of them, and I'm not entirely sure what the
difference is:
Road TOID Street USRN 10
RoadLink TOID Street USRN 8
Both of them have exactly the same data format.
The TOIDs in those datasets can then be cross-referenced against OS
OpenNames to give the OS name for the linked USRNs. Although this isn't,
always, the same as the official USRN name of the street, which can be
confusing. But that's because OS (like OSM) maps what is visible, rather
than necessarily what is documented, and if a street has a name by which
it is commonly referred to then that's what goes on the OS maps even if
it has a different name in the USRN.
Mark
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