[Talk-GB] West Mids Ward Boundaries

Ed Loach ed at loach.me.uk
Wed Apr 7 11:01:25 BST 2010


Steve wrote:

> I'd prefer to see boundaries handled by an automated (and
nationwide) 
> import process, as the OS data is likely to be at least as good as

> contributors' own efforts and usually much better AND they are
committed 
> to maintaining it going forward. Which seems a good opportunity to
mention 
> that those of you working on the technical aspects of using the OS
data 
> need to have a thought to how future updates will be handled. It's
much 
> easier to insert a load of brand new data than to update existing
data 
> from a refreshed set of source data in the future. You will have
to be 
> able to distinguish new data to be inserted from existing data
that may 
> have changed and existing data that may need deleting. Just a
thought.

As I suspect there won't be any ward data currently in, the idea
sounds somewhat appealing, BUT I have not yet seen anywhere where
imported boundaries have been done well and have spent many an hour
tidying up the results (recently in Haiti and ongoing in GA, USA).
Examples include adjacent areas using overlapping ways rather than a
single shared way, an admin boundary being imported as a single way
which then needs splitting (and any duplicate ways de-duplicating)
before a relation can be created, and so on. If such an import were
to be done, it should be done well or not at all.

Ed






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