[OSM-talk] National borders - mapnik

[Shaun McDonald]

On 29 May 2008, at 10:35, Andy Robinson (blackadder-lists) wrote:

> Steve Chilton wrote:
>> Sent: 28 May 2008 10:01 PM
>> To: Beau Gunderson
>> Cc: talk at openstreetmap.org
>> Subject: Re: [OSM-talk] National borders - mapnik
>>
>> See example from UK: http://dev.openstreetmap.org/~steve8/borders.jpg
>> Border between countries England and Scotland is one way (actually  
>> probably
>> several ways), tagged admin_level=2.
>> Border between counties Cumbria and Northumberland is another way/ 
>> s, tagged
>> admin_level=6.
>> Implicitly the country border is part of the collection of ways  
>> that make
>> up the Cumbria county border.
>> There is only one border there, and there only needs to be one "way".
>> NB: If you want polygons for areas you probably have to post- 
>> process the
>> data to compile them or use relations to group them.
>
> This issue comes up with quite a lot of tags. Bus routes for  
> instance where
> you have more than one route reference running along the same way.  
> In that
> instance I use a "|" between each route reference, could we not do  
> the same
> for admin_level data? ie add all the numbers that are relevant,  
> because in
> some cases perhaps lower ones do not exist for the location.
>

I would have thought that bus routes would have been done by  
relations, with one or more relations for the whole route. It is then  
up to the renderer to deal with the relations appropriately. This  
means that you can enter more specific information about each route as  
part of the relation tags. It is highly unlikely that a bus route will  
go the same route for the whole route.

Shaun