# [OSM-talk] Ditches

Tue Dec 15 08:57:38 GMT 2009

```I encounter a similar situation all the time - usually in the context of
public footpaths with short foot plank or sleeper bridges over ditches or
very small streams in the countryside.

My practice - which is open to change if there is a better solution that is
widely accepted - is:

1. Split the way over the bridge even though it is short (in fact I
sometimes have to go further and also split the way in the middle of the
bridge if it is on a boundary and the footpath reference number changes!).

2. Tag the bridge as bridge=yes and layer=1.

3. My rationale for layer=1 (rather than tagging the ditch / stream as
layer=-1) is that the ditch / stream (as and when fully mapped) will run at
the same level into bigger streams, rivers etc. and these will almost
certainly already be tagged (imho correctly) as level=0. Although there may
be no physical ascent to get onto the bridge plank (indeed it is often a
descent either side as the plank may be a little below the surrounding field
level even though it is above the stream) the concept in my mind is that we
have gone 'up' relative to something that is at the general level of the
countryside to the same extent as, say, a river is at the same general level
even though it flows between banks and the surface of the water is actually
below the land (most of the time anyway - not last month!).

Mike Harris

_____

From: Anthony [mailto:osm at inbox.org]
Sent: 15 December 2009 02:31
To: openstreetmap
Subject: [OSM-talk] Ditches

In a park is a ditch.  There is a very small bridge going over the ditch.
I've tagged the ditch with barrier=ditch.  Should the ditch be layer=-1?
Even though the park is layer=0?  Should I use barrier=entrance on the node
where the ways overlap, bridge=yes on the bridge (which means splitting the
way for a very short bridge), both, something else?

(Actually, there are three bridges, one of which carries motor vehicle
traffic and two which do not.)

http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG
http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk/attachments/20091215/2c1e54d9/attachment.html>
```