Re: [Tagging] Culverts and Fords

[Paul Johnson]

On Mar 2, 2018 08:42, "Vao Matua"  wrote:

Thank you Ralph, I understand your perspective, but have to disagree a bit
(I'm not looking for a battle, however).

A ford is a stack of layers that are directly adjacent vertically, with the
road slightly below the stream/river.  In the dry season a ford is only a
road and only becomes a ford when a watercourse flows over the top of the
road.

A culvert is a part of of road construction, a culvert would not exist
without the road, but the culvert is utilized by the stream.  Personally I
have physically installed culverts in road profiles where there is no
watercourse.  If I try to add a culvert in JOSM without an additional tag I
get a validation warning.


These aren't mutually exclusive, fords with culverts under them are fairly
common in Oklahoma.
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Vao Matua]

Rendering will always be an imperfect representation of the real world.
I still feel that there is an inconsistency with the way these two
circumstances are handled, but understand that this is one of the non-open
parts of Open Street Map.
I'm done trying to swim upstream on this.

On Fri, Mar 2, 2018 at 7:17 AM, Volker Schmidt  wrote:

> The layers tag in OSM is only to enable the renderer to display/draw
> crossing OSM elements correctly. The element with the higher layer value is
> drown over the ones with lower layer values.
>
> In the case of the ford the waterway and the highway are on the same layer
> and share a node, which represents the ford (assuming that highway and
> waterway are line objects. If the waterway and/or the highway are drawn as
> polygons, then the ford becomes a line or a polygon.)
>
> In case of a culvert the objects are not on the same layer. The highway is
> above the waterway (which may be intermittent or a wadi). Hence a common
> node is not correct. You could argue that the culvert becomes a node on the
> lower way, that is not connected with the highway above. It would have to
> be drawn exactly on the crossing point, without being part of the highway
> above. A non-zero length culvert is most likely easier to draw, and also
> closer to reality.
> Again, when the waterway is drawn as a Polygon, the culvert becomes a
> polygon.
>
> On 2 March 2018 at 15:41, Vao Matua  wrote:
>
>> Thank you Ralph, I understand your perspective, but have to disagree a
>> bit (I'm not looking for a battle, however).
>>
>> A ford is a stack of layers that are directly adjacent vertically, with
>> the road slightly below the stream/river.  In the dry season a ford is only
>> a road and only becomes a ford when a watercourse flows over the top of the
>> road.
>>
>> A culvert is a part of of road construction, a culvert would not exist
>> without the road, but the culvert is utilized by the stream.  Personally I
>> have physically installed culverts in road profiles where there is no
>> watercourse.  If I try to add a culvert in JOSM without an additional tag I
>> get a validation warning.
>>
>> Wouldn't a road/stream crossing without a culvert or bridge be called a
>> dam?
>>
>> Isn't a culvert similar in rendering to an embankment?  An embankment is
>> a tag applied to a road or railroad, but it is a level beneath the road or
>> railroad.  A culvert happens to be perpendicular or so to the road rather
>> than adjacent to it.
>>
>> Part of this discussion also is a matter of scale.  At some rendering of
>> a map even a place like Paris would be displayed as a node.  In the same
>> way a culvert displayed as a node would be appropriate at certain zoom
>> levels.
>>
>> I think an easy solution is to make the rendering rule for culverts be a
>> layer below the road and allowed to be a node.
>>
>> I think this is an interesting discussion and is helping me understand
>> different points of view, thanks.
>>
>> Emmor
>>
>> On Fri, Mar 2, 2018 at 12:39 AM, Ralph Aytoun 
>> wrote:
>>
>>> The real easy way to understand *culverts* and *fords* for
>>> OpenStreetMap is about the layers they are on and this dictates the nodes
>>> they use.
>>>
>>>
>>>
>>> For a  *ford* the stream/river is at the same level as the road
>>> (effectively *layer=0*) and therefore they are able to share a node.
>>>
>>>
>>>
>>> Because a culvert (*layer=-1*)  is not on the same level as the road
>>> but passes underneath so it cannot share a node with the road and therefore
>>> the culvert is attributed to the river/stream with a node either side of
>>> the road.
>>>
>>>
>>>
>>> With a *bridge* the road (*layer 1*)  is not on the same level with the
>>> stream/river so again cannot share a node and therefore the bridge is
>>> attributed to the road with a node at each end of the bridge.
>>>
>>>
>>>
>>> Hope this will be of help in understanding the problem.
>>>
>>>
>>>
>>>
>>>
>>> Sent from Mail  for
>>> Windows 10
>>>
>>>
>>>
>>
>>
>> ___
>> Tagging mailing list
>> Tagging@openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>>
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Martin Koppenhoefer]

2018-03-02 16:17 GMT+01:00 Volker Schmidt :

> In case of a culvert the objects are not on the same layer. The highway is
> above the waterway (which may be intermittent or a wadi).
>


I aree it is nitpicking, but it depends on the geometry: I'd see the osm
highway=* object as representing the "whole road". The culvert would go
through the road (if you don't reduce the road to its surface), at least in
some cases.


Cheers,
Martin
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Martin Koppenhoefer]

2018-03-02 15:41 GMT+01:00 Vao Matua :

>
> A culvert is a part of of road construction, a culvert would not exist
> without the road, but the culvert is utilized by the stream.  Personally I
> have physically installed culverts in road profiles where there is no
> watercourse.  If I try to add a culvert in JOSM without an additional tag I
> get a validation warning.
>
> Wouldn't a road/stream crossing without a culvert or bridge be called a
> dam?
>
> Isn't a culvert similar in rendering to an embankment?  An embankment is a
> tag applied to a road or railroad, but it is a level beneath the road or
> railroad.  A culvert happens to be perpendicular or so to the road rather
> than adjacent to it.
>


it is about the distinction "property" and "feature". For example
"embankment" can be a property of a road or railroad way (key: embankment),
or it can be a feature of it's own: man_made=embankment
Similarly, a road can be signed as being on a bridge (property bridge=yes)
but the bridge can also be mapped on its own: man_made=bridge

If you want to map a culvert without anything else, you could use
man_made=culvert

Cheers,
Martin
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Volker Schmidt]

The layers tag in OSM is only to enable the renderer to display/draw
crossing OSM elements correctly. The element with the higher layer value is
drown over the ones with lower layer values.

In the case of the ford the waterway and the highway are on the same layer
and share a node, which represents the ford (assuming that highway and
waterway are line objects. If the waterway and/or the highway are drawn as
polygons, then the ford becomes a line or a polygon.)

In case of a culvert the objects are not on the same layer. The highway is
above the waterway (which may be intermittent or a wadi). Hence a common
node is not correct. You could argue that the culvert becomes a node on the
lower way, that is not connected with the highway above. It would have to
be drawn exactly on the crossing point, without being part of the highway
above. A non-zero length culvert is most likely easier to draw, and also
closer to reality.
Again, when the waterway is drawn as a Polygon, the culvert becomes a
polygon.

On 2 March 2018 at 15:41, Vao Matua  wrote:

> Thank you Ralph, I understand your perspective, but have to disagree a bit
> (I'm not looking for a battle, however).
>
> A ford is a stack of layers that are directly adjacent vertically, with
> the road slightly below the stream/river.  In the dry season a ford is only
> a road and only becomes a ford when a watercourse flows over the top of the
> road.
>
> A culvert is a part of of road construction, a culvert would not exist
> without the road, but the culvert is utilized by the stream.  Personally I
> have physically installed culverts in road profiles where there is no
> watercourse.  If I try to add a culvert in JOSM without an additional tag I
> get a validation warning.
>
> Wouldn't a road/stream crossing without a culvert or bridge be called a
> dam?
>
> Isn't a culvert similar in rendering to an embankment?  An embankment is a
> tag applied to a road or railroad, but it is a level beneath the road or
> railroad.  A culvert happens to be perpendicular or so to the road rather
> than adjacent to it.
>
> Part of this discussion also is a matter of scale.  At some rendering of a
> map even a place like Paris would be displayed as a node.  In the same way
> a culvert displayed as a node would be appropriate at certain zoom levels.
>
> I think an easy solution is to make the rendering rule for culverts be a
> layer below the road and allowed to be a node.
>
> I think this is an interesting discussion and is helping me understand
> different points of view, thanks.
>
> Emmor
>
> On Fri, Mar 2, 2018 at 12:39 AM, Ralph Aytoun 
> wrote:
>
>> The real easy way to understand *culverts* and *fords* for OpenStreetMap
>> is about the layers they are on and this dictates the nodes they use.
>>
>>
>>
>> For a  *ford* the stream/river is at the same level as the road
>> (effectively *layer=0*) and therefore they are able to share a node.
>>
>>
>>
>> Because a culvert (*layer=-1*)  is not on the same level as the road but
>> passes underneath so it cannot share a node with the road and therefore the
>> culvert is attributed to the river/stream with a node either side of the
>> road.
>>
>>
>>
>> With a *bridge* the road (*layer 1*)  is not on the same level with the
>> stream/river so again cannot share a node and therefore the bridge is
>> attributed to the road with a node at each end of the bridge.
>>
>>
>>
>> Hope this will be of help in understanding the problem.
>>
>>
>>
>>
>>
>> Sent from Mail  for
>> Windows 10
>>
>>
>>
>
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Vao Matua]

Thank you Ralph, I understand your perspective, but have to disagree a bit
(I'm not looking for a battle, however).

A ford is a stack of layers that are directly adjacent vertically, with the
road slightly below the stream/river.  In the dry season a ford is only a
road and only becomes a ford when a watercourse flows over the top of the
road.

A culvert is a part of of road construction, a culvert would not exist
without the road, but the culvert is utilized by the stream.  Personally I
have physically installed culverts in road profiles where there is no
watercourse.  If I try to add a culvert in JOSM without an additional tag I
get a validation warning.

Wouldn't a road/stream crossing without a culvert or bridge be called a dam?

Isn't a culvert similar in rendering to an embankment?  An embankment is a
tag applied to a road or railroad, but it is a level beneath the road or
railroad.  A culvert happens to be perpendicular or so to the road rather
than adjacent to it.

Part of this discussion also is a matter of scale.  At some rendering of a
map even a place like Paris would be displayed as a node.  In the same way
a culvert displayed as a node would be appropriate at certain zoom levels.

I think an easy solution is to make the rendering rule for culverts be a
layer below the road and allowed to be a node.

I think this is an interesting discussion and is helping me understand
different points of view, thanks.

Emmor

On Fri, Mar 2, 2018 at 12:39 AM, Ralph Aytoun 
wrote:

> The real easy way to understand *culverts* and *fords* for OpenStreetMap
> is about the layers they are on and this dictates the nodes they use.
>
>
>
> For a  *ford* the stream/river is at the same level as the road
> (effectively *layer=0*) and therefore they are able to share a node.
>
>
>
> Because a culvert (*layer=-1*)  is not on the same level as the road but
> passes underneath so it cannot share a node with the road and therefore the
> culvert is attributed to the river/stream with a node either side of the
> road.
>
>
>
> With a *bridge* the road (*layer 1*)  is not on the same level with the
> stream/river so again cannot share a node and therefore the bridge is
> attributed to the road with a node at each end of the bridge.
>
>
>
> Hope this will be of help in understanding the problem.
>
>
>
>
>
> Sent from Mail  for
> Windows 10
>
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

[Tagging] Culverts and Fords

[Ralph Aytoun]

The real easy way to understand culverts and fords for OpenStreetMap is about 
the layers they are on and this dictates the nodes they use.

For a  ford the stream/river is at the same level as the road (effectively 
layer=0) and therefore they are able to share a node.

Because a culvert (layer=-1)  is not on the same level as the road but passes 
underneath so it cannot share a node with the road and therefore the culvert is 
attributed to the river/stream with a node either side of the road.

With a bridge the road (layer 1)  is not on the same level with the 
stream/river so again cannot share a node and therefore the bridge is 
attributed to the road with a node at each end of the bridge.

Hope this will be of help in understanding the problem.


Sent from Mail for Windows 10

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Richard]

On Wed, Feb 28, 2018 at 10:06:16PM +, Andy Townsend wrote:
> On 28/02/2018 21:31, Vao Matua wrote:
> >
> >What I would like to do is simply merge a node of the road and a node of
> >the stream and give it the tag tunnel=culvert (when I do this JOSM
> >complains)
> Because that would then be a ford rather than a culvert - you're implying
> that at a certain point (the joining node) you've got your feet on the road
> and in the stream?

it does not imply that. A shared node merely implies that the stream
and the road are *somehow* connected. A shared node with own tags
can define any kind of such connection like an elevator for example.

It is a matter of interpretation and can be defined what exactly the 
"connection" means.
So lets define this shared node to mean "the culvert is part of the road 
construction". 
Indeed I have very rarely seen culverts going deep enough under a road that
you could claim they are a separate construction from the road - most of
them are integral part of the road construcion.

It is also not quite true that the culvert has absolutely no relevance for
the road above it - typically the embankment will be narrower in this place,
there may be small walls on the side, bumps and frequently require attention 
from the driver.

Of course I have proposed it before:)
https://wiki.openstreetmap.org/wiki/Proposed_features/Simple_one_node_culvert_or_bridge


Richard

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Jo]

the water is tunneling under the road, through a narrow passage. It's not
the road that goes through a tunnel.

2018-03-01 17:40 GMT+01:00 Vao Matua :

> Thank you all for the explanations.
> I think that my issue might have to do with UK English usage.  I  would
> never call a road tunnel a "culvert", I  typically only work and map in a
> rural setting and a culvert is only a passage way for water, and is only
> used at a road or path crossing.
>
> While a ford is something shared by a road and a stream one is still under
> the other, but the rules for rendering assume that the road is underneath.
> In the OSM ford wiki  one
> photograph shows the path on top of the ford using the stepping stones.
> The Wikipedia reference cited on
> the OSM culvert wiki
>  only shows
> stream examples.
> Therefore, why not have a rendering rule for culverts in the same way
> there is a rendering for a ford?
>
> This has been an interesting thought process and I'm probably just lazy
> not wanting to split a watercourse twice and add a tag to the way as
> opposed to snapping a road or watercourse node and adding a tag to the node.
>
> Keep mapping
>
> On Wed, Feb 28, 2018 at 5:11 PM, Dave Swarthout 
> wrote:
>
>> >If 2 ways share a node, then they must be connected to each other. ie on
>> the same layer. So one can't be above/below the other. A road and a stream
>> crossing on the same layer is a ford.
>> >If you tag the shared node as a tunnel, then you don't know which way
>> goes through the tunnel.  Does the stream go through a tunnel, or does the
>> road go through a tunnel, or both?
>>
>> >It is much more useful to map tunnels/bridges as a way. If you know
>> there is a tunnel, but don't know how long the tunnel is, you can estimate
>> it. ie based on the width of the road. You can add a note to say the exact
>> >length/position is estimated
>>
>> Excellent explanation. Agree totally.
>>
>> On Thu, Mar 1, 2018 at 7:48 AM, Craig Wallace 
>> wrote:
>>
>>> On 2018-02-28 23:21, Vao Matua wrote:
>>>
 François

 I don't have an example.  I was trying to think of an example where
 layer would be needed for a stream/road crossing.  A pipe would probably be
 a better example.

 Sorry to cause a distraction.

 My real question is "Why not allow tunnel=culvert to be a node?"

 Emmor

>>>
>>> If 2 ways share a node, then they must be connected to each other. ie on
>>> the same layer. So one can't be above/below the other. A road and a stream
>>> crossing on the same layer is a ford.
>>> If you tag the shared node as a tunnel, then you don't know which way
>>> goes through the tunnel.  Does the stream go through a tunnel, or does the
>>> road go through a tunnel, or both?
>>>
>>> It is much more useful to map tunnels/bridges as a way. If you know
>>> there is a tunnel, but don't know how long the tunnel is, you can estimate
>>> it. ie based on the width of the road. You can add a note to say the exact
>>> length/position is estimated.
>>>
>>>
>>> ___
>>> Tagging mailing list
>>> Tagging@openstreetmap.org
>>> https://lists.openstreetmap.org/listinfo/tagging
>>>
>>
>>
>>
>> --
>> Dave Swarthout
>> Homer, Alaska
>> Chiang Mai, Thailand
>> Travel Blog at http://dswarthout.blogspot.com
>>
>> ___
>> Tagging mailing list
>> Tagging@openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>>
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Vao Matua]

Thank you all for the explanations.
I think that my issue might have to do with UK English usage.  I  would
never call a road tunnel a "culvert", I  typically only work and map in a
rural setting and a culvert is only a passage way for water, and is only
used at a road or path crossing.

While a ford is something shared by a road and a stream one is still under
the other, but the rules for rendering assume that the road is underneath.
In the OSM ford wiki  one
photograph shows the path on top of the ford using the stepping stones.
The Wikipedia reference cited on the OSM
culvert wiki  only
shows stream examples.
Therefore, why not have a rendering rule for culverts in the same way there
is a rendering for a ford?

This has been an interesting thought process and I'm probably just lazy not
wanting to split a watercourse twice and add a tag to the way as opposed to
snapping a road or watercourse node and adding a tag to the node.

Keep mapping

On Wed, Feb 28, 2018 at 5:11 PM, Dave Swarthout 
wrote:

> >If 2 ways share a node, then they must be connected to each other. ie on
> the same layer. So one can't be above/below the other. A road and a stream
> crossing on the same layer is a ford.
> >If you tag the shared node as a tunnel, then you don't know which way
> goes through the tunnel.  Does the stream go through a tunnel, or does the
> road go through a tunnel, or both?
>
> >It is much more useful to map tunnels/bridges as a way. If you know there
> is a tunnel, but don't know how long the tunnel is, you can estimate it. ie
> based on the width of the road. You can add a note to say the exact
> >length/position is estimated
>
> Excellent explanation. Agree totally.
>
> On Thu, Mar 1, 2018 at 7:48 AM, Craig Wallace 
> wrote:
>
>> On 2018-02-28 23:21, Vao Matua wrote:
>>
>>> François
>>>
>>> I don't have an example.  I was trying to think of an example where
>>> layer would be needed for a stream/road crossing.  A pipe would probably be
>>> a better example.
>>>
>>> Sorry to cause a distraction.
>>>
>>> My real question is "Why not allow tunnel=culvert to be a node?"
>>>
>>> Emmor
>>>
>>
>> If 2 ways share a node, then they must be connected to each other. ie on
>> the same layer. So one can't be above/below the other. A road and a stream
>> crossing on the same layer is a ford.
>> If you tag the shared node as a tunnel, then you don't know which way
>> goes through the tunnel.  Does the stream go through a tunnel, or does the
>> road go through a tunnel, or both?
>>
>> It is much more useful to map tunnels/bridges as a way. If you know there
>> is a tunnel, but don't know how long the tunnel is, you can estimate it. ie
>> based on the width of the road. You can add a note to say the exact
>> length/position is estimated.
>>
>>
>> ___
>> Tagging mailing list
>> Tagging@openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>
>
>
> --
> Dave Swarthout
> Homer, Alaska
> Chiang Mai, Thailand
> Travel Blog at http://dswarthout.blogspot.com
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Dave Swarthout]

 >If 2 ways share a node, then they must be connected to each other. ie on
the same layer. So one can't be above/below the other. A road and a stream
crossing on the same layer is a ford.
>If you tag the shared node as a tunnel, then you don't know which way goes
through the tunnel.  Does the stream go through a tunnel, or does the road
go through a tunnel, or both?

>It is much more useful to map tunnels/bridges as a way. If you know there
is a tunnel, but don't know how long the tunnel is, you can estimate it. ie
based on the width of the road. You can add a note to say the exact
>length/position is estimated

Excellent explanation. Agree totally.

On Thu, Mar 1, 2018 at 7:48 AM, Craig Wallace 
wrote:

> On 2018-02-28 23:21, Vao Matua wrote:
>
>> François
>>
>> I don't have an example.  I was trying to think of an example where layer
>> would be needed for a stream/road crossing.  A pipe would probably be a
>> better example.
>>
>> Sorry to cause a distraction.
>>
>> My real question is "Why not allow tunnel=culvert to be a node?"
>>
>> Emmor
>>
>
> If 2 ways share a node, then they must be connected to each other. ie on
> the same layer. So one can't be above/below the other. A road and a stream
> crossing on the same layer is a ford.
> If you tag the shared node as a tunnel, then you don't know which way goes
> through the tunnel.  Does the stream go through a tunnel, or does the road
> go through a tunnel, or both?
>
> It is much more useful to map tunnels/bridges as a way. If you know there
> is a tunnel, but don't know how long the tunnel is, you can estimate it. ie
> based on the width of the road. You can add a note to say the exact
> length/position is estimated.
>
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>



-- 
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Warin]

A culvert goes under the road and only carries the waterway. So it does 
not 'exist' for the road. As such the culvert would be tagged on the 
waterway and not on the roadway. The length of the culvert ... well it 
is at least as wide as the road, if you cannot see it in imagery simply 
make it a bit wider than the roads width. In Australia many streams are 
intermittent - meaning the at water is not frequently there .. that 
makes seeing these culverts difficult - I simply use the road widths if 
I cannot see them.


A ford is where a waterway crosses a road, so needs to be on both 
waterway and roadway. So this tag should take place on both waterway and 
roadway where they share a node (or a way). These too can nbe hard to 
see in Australia, if I cannot make out what it is (ford or culvert) I 
don't tag it .. that leaves an error, but it is not something I can 
identify so I leave it.


A reason whey tagging tunnel=culvert on a nod that has n=both road and 
waterway is that the renders then have to decide it the tunnel is on the 
road or the waterway .. or possibly there are 2 tunnels ... one on the 
road the other on the waterway ... too complex for the renders... the 
mappers have to decide.



On 01-Mar-18 08:31 AM, Vao Matua wrote:
Can someone help me understand two different types of stream and road 
crossings?


A ford can be a node or 
a way (180,749 nodes & 63,842 ways)


However, a culvert 
can only be a 
way (691,972 ways)


In many circumstances from imagery I can see a stream crossing under a 
road without a bridge or ford and therefore I assume that it is a 
culvert, but typically cannot see the ends to split the watercourse.  
Why does a culvert have to be a way rather than a way OR a node?


What I would like to do is simply merge a node of the road and a node 
of the stream and give it the tag tunnel=culvert (when I do this JOSM 
complains)


In the case where a culvert carries a watercourse over a road then it 
would make sense to create a way and layer=1


Any insights for this apparent inconsistency?


___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging



___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Craig Wallace]

On 2018-02-28 23:21, Vao Matua wrote:

François

I don't have an example.  I was trying to think of an example where 
layer would be needed for a stream/road crossing.  A pipe would 
probably be a better example.


Sorry to cause a distraction.

My real question is "Why not allow tunnel=culvert to be a node?"

Emmor


If 2 ways share a node, then they must be connected to each other. ie on 
the same layer. So one can't be above/below the other. A road and a 
stream crossing on the same layer is a ford.
If you tag the shared node as a tunnel, then you don't know which way 
goes through the tunnel.  Does the stream go through a tunnel, or does 
the road go through a tunnel, or both?


It is much more useful to map tunnels/bridges as a way. If you know 
there is a tunnel, but don't know how long the tunnel is, you can 
estimate it. ie based on the width of the road. You can add a note to 
say the exact length/position is estimated.


___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Vao Matua]

 François

I don't have an example.  I was trying to think of an example where layer
would be needed for a stream/road crossing.  A pipe would probably be a
better example.

Sorry to cause a distraction.

My real question is "Why not allow tunnel=culvert to be a node?"

Emmor


2018-02-28 22:31 GMT+01:00 Vao Matua :

> In the case where a culvert carries a watercourse over a road then it
> would make sense to create a way and layer=1
>

Can you provide examples of such a culvert please?

IMHO this can't be called a culvert since there is pretty no point to cover
the water course if it is over the road.
This maybe a canal (waterway=canal, eventually with bridge=aqueduct on it)
or the road can go through a tunnel like here :
https://photorator.com/photos/images/underwater-road-xpost-
from-rwoahdude-20901.jpg

All the best

François



On Wed, Feb 28, 2018 at 2:27 PM, François Lacombe  wrote:

> Hi,
>
> 2018-02-28 22:31 GMT+01:00 Vao Matua :
>
>> In the case where a culvert carries a watercourse over a road then it
>> would make sense to create a way and layer=1
>>
>
> Can you provide examples of such a culvert please?
>
> IMHO this can't be called a culvert since there is pretty no point to
> cover the water course if it is over the road.
> This maybe a canal (waterway=canal, eventually with bridge=aqueduct on it)
> or the road can go through a tunnel like here :
> https://photorator.com/photos/images/underwater-road-xpost-
> from-rwoahdude-20901.jpg
>
> All the best
>
> François
>
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[François Lacombe]

Hi,

2018-02-28 22:31 GMT+01:00 Vao Matua :

> In the case where a culvert carries a watercourse over a road then it
> would make sense to create a way and layer=1
>

Can you provide examples of such a culvert please?

IMHO this can't be called a culvert since there is pretty no point to cover
the water course if it is over the road.
This maybe a canal (waterway=canal, eventually with bridge=aqueduct on it)
or the road can go through a tunnel like here :
https://photorator.com/photos/images/underwater-road-xpost-from-rwoahdude-20901.jpg

All the best

François
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Culverts and Fords

[Andy Townsend]

On 28/02/2018 21:31, Vao Matua wrote:


What I would like to do is simply merge a node of the road and a node 
of the stream and give it the tag tunnel=culvert (when I do this JOSM 
complains)
Because that would then be a ford rather than a culvert - you're 
implying that at a certain point (the joining node) you've got your feet 
on the road and in the stream?




In the case where a culvert carries a watercourse over a road then it 
would make sense to create a way and layer=1


That sounds (at least in English English) like some sort of bridge 
(aqueduct) rather than a culvert - though this did come up the last time 
that culverts were discussed on this list** - someone found an old 
picture of a car going over a bridge over a culvert and thought that the 
picture's title ("the culvert") referred to the bridge.


If you genuinely don't know how a road crosses a waterway then you can 
of course just have the one crossing the other.  QA sites will flag this 
as an error (which is correct - it is) but if you don't have any 
information about how to correct the error (is there a ford?  bridge? is 
there no bridge but the stream runs in a box culvert?) then to my mind 
there's no problem leaving the "error" there so that someone who has 
more information can correct it.


Best Regards,

Andy

** 
https://duckduckgo.com/html?q=culvert%20site%3Ahttps%3A%2F%2Flists.openstreetmap.org%2Fpipermail%2F 
gets some hits.  There were also a bunch of discussions around the time 
that 
https://wiki.openstreetmap.org/wiki/Proposed_features/Simple_one_node_bridge 
was created - so have a look at the lists then.



___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

[Tagging] Culverts and Fords

[Vao Matua]

Can someone help me understand two different types of stream and road
crossings?

A ford can be a node or a way
(180,749 nodes & 63,842 ways)

However, a culvert can
only be a way (691,972 ways)

In many circumstances from imagery I can see a stream crossing under a road
without a bridge or ford and therefore I assume that it is a culvert, but
typically cannot see the ends to split the watercourse.  Why does a culvert
have to be a way rather than a way OR a node?

What I would like to do is simply merge a node of the road and a node of
the stream and give it the tag tunnel=culvert (when I do this JOSM
complains)

In the case where a culvert carries a watercourse over a road then it would
make sense to create a way and layer=1

Any insights for this apparent inconsistency?
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging