[OSM-talk] When is a bridge not a bridge?

Marc Schütz schuetzm at gmx.net
Fri Jan 23 17:09:40 GMT 2009

(Forwarding to list)

Am Friday 23 January 2009 17:28:17 schrieben Sie:
> As I understood the text of the wiki when I first started, layer 0 is
> the general level of the terrain, so levels 1, 2, 3, 4, 5 are above
> the ground on successively higher bridges, and -1, -2, -3, -4, and -5
> in successively deeper trenches.

Indeed, that's what the wiki page says. Unfortunately I cannot find the place 
where the discussion took place when the feature was introduced (probably 
before today's "standardization process"); I'm pretty sure that this was not 

One could argue that because the default is layer=0, the natural surface would 
be in this layer. However, we do not model the natural surface, so this seems 
to be a completely arbitrary limitation. Lacking a definition for "natural 
surface", there isn't even an application where this information could be 

Of course it does no harm either, so this is probably just nitpicking.

Regards, Marc

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.openstreetmap.org/pipermail/talk/attachments/20090123/6a8effbd/attachment.pgp>

More information about the talk mailing list