[Talk-GB] Missing place=city nodes: Manchester, Leeds

David Earl david at frankieandshadow.com
Sun Apr 28 14:48:05 UTC 2013


On 28/04/2013 15:21, Andrew wrote:
> David Earl <david at ...> writes:
>
>>
>> In general, it shouldn't be necessary to
> have a node and an area which
>> represent the same thing.
>
> In this case the nodes and areas do not
> represent the same thing. The areas are
> the local government districts called
> Leeds and Manchester but the nodes are
> the settlements of Leeds excluding for
> instance Morley and Manchester
> including for instance Salford.

OK, City of Manchester and Greater Manchester aren't the same thing. But
there will usually be an administration that _is_ the place (i.e. the
boundary of the place follows the boundary of the adminstrative area),
even when there is a larger unitary authority encompassing more than one
such place. Place has little meaning otherwise - a town or civil parish
or whatever _is_ the place.

There is an argument that says 'place' is an informal concept that
should only be represented as a node, different from administrative
boundaries. This gets perilously close to mapping for the renderer
though ("I want a label HERE").

There's also a useful concept of the "urban envelope" where you want to
draw a grey splodge on a map to represent a built-up area. The various
urban landuses almost get this, but for a clean map you don't really
always want the small outliers or rural dwellings that might be marked
landuse=residential. Once could argue that place areas serve that need.

Whatever, I suspect it has been done in any and all combinations,
because informal place predates the more formal (or formerly
inaccessible to us) admin boundaries.

David









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