> > Message: 10 > Date: Thu, 21 Aug 2008 14:11:34 +0100 > From: "Andy Allan" <[EMAIL PROTECTED]> > Subject: Re: [OSM-talk] SOTM relations workshop: results > To: "Ben Laenen" <[EMAIL PROTECTED]> > Cc: talk@openstreetmap.org > Message-ID: > <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1 > > On Thu, Aug 21, 2008 at 12:14 PM, Ben Laenen <[EMAIL PROTECTED]> wrote: > > > If the route goes both ways between A and D, the ways have no roles. > > > > A ----> B <---- C -----> D > > | | > > v v > > E ----> F > > > > If in this example the route goes from A to D via ABEFCD and the route > > goes from D to A via DCBA, the roles are as follows: > > AB, CD: no role > > BC, BE, EF: forward > > CF: backward > > Spot on. Given that I know you're both agreeing with one another, and > it's still confusing, just imagine how hard it's going to be to > explain it to the other 60,000 OSMers :-) > > I'm hoping that having rendered examples, like > http://www.flickr.com/photos/gravitystorm/2771299743/ should at least > keep people on the right track. > > Cheers, > Andy
I have just seen the conversation about large forests etc and it is something I have been thinking about. I have just being using a relationship to do administrative boundary for Suffolk which was very simple and it led me to think if we should be using relationships for other boundaries. http://wiki.openstreetmap.org/index.php/Relations/Proposed/Boundaries Why not use the boundary relation concept to define the boundary for a school, a park, a forest or a lake? If one does large areas like that then the ways that make up the boundary can be sensible lengths, can be split up as needed for other tagging purposes and one does not need to ever overload multiple ways onto the same sequence of nodes. Here is the discussion about boundaries. To give a concrete example: We have a local park, part of which is bordered by a road, path by a hedge and part by a fence. The borough boundary comes along a section of the fence and along part of one of the roads. Currently I create a way for the park that encompases the whole park. For the road sections I create a way that shares nodes with the park as appropriate. When I come to do the administrative boundary I find myself needing to create a new way that goes down the side of the park along the fence. All this seems very complicated and unnecessary. How would it work using relationships? I would then just snip the roads at the boundaries of the park. I would like to then create a section of way tagged 'fence' for the non-road boundaries for the park. I would then create a new relation called 'boundary=park' and associate this with the relevant ways, and another called 'boundary=administrative' for the borough council boundary. I realise this is a little radical and could possibly result in the fudge (as I have always seen it) of ways being used to represent areas being deprecated. Does this make any sense? Regards, Peter _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
