I always use layer= , even when there is only a single bridge. It avoids problems with the validator and - crucially - makes it clear that the two crossing ways do not have access to each other. (It also improves rendering but I probably shouldn't mention that or I'll get flamed!).
Example - common in my area: If a hiking trail crosses over a canal (and its towpath) by a bridge then bridge=yes and layer=1 makes it clear that the canal and the trail are at two different vertical levels and that you cannot get from the trail to the towpath of the canal. If there is a ramp or steps from the hiking trail to give access to the towpath this can then be added as a separate way in the appropriate place. There is a theoretical dilemma as to what layer to give the ramp but I usually default to level=0 unless there is a special complexity at a particular junction that needs more explicit layering. Mike Harris > -----Original Message----- > From: Dave F. [mailto:dave...@madasafish.com] > Sent: 25 November 2009 21:58 > Cc: OSM Talk > Subject: Re: [OSM-talk] Bridge on Hiking Trails > > Shaun McDonald wrote: > > on the way use highway=footway; bridge=yes; layer=1. > > I didn't think the layer=1 was necessary when there's only > one bridge - it defaults to display above other objects. > I only use in there a multiple bridges crossing each other. > > Dave F. > > > > _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk