[HOT] Central African Republic, use of landcover=bare_earth

[dies38061 at mypacks.net]

Thanks for your comments, Jaakko.

My reasoning when along the lines of "track = present due to traffic & bare_earth in the regions noted is only present due to persistent traffic (foot and/or vehicle) => highway=track + area=yes <= it has been proposed that large highways (like, 8 lanes) be rendered as areas rather than ways".  The main intent was to provide indication of an area which provided no impediment to human or vehicular traffic.  Maybe a better approach would be to use a landcover=bare_earth (landcover formally implies area=yes, actually) alone.  The access key relates to legality of access, not accessibility per se; it is the highway key which relates directly to vehicular accessibility ... which leads back to applying an area=yes to a highway=(something).

On a related note is the matter of whether it is worth mapping this ... good question from Filip.  It depends on whether the areas which (in the current imagery) appear _not_ to be bare earth are typically vehicle-accessible.  If they are, then I would say that a) it is OK to have tracks / ways terminating without connection to others and b) it is not at all needed to do what I've done (and I'll remove the bare_earth tags in order to make the map as interpretable as possible).  It boils down to whether there is any worth in re physical accessibility (not legal accessibility) to locations.

Thanks for additional comments.

--Courtland (ceyockey)



-----Original Message-----

From: "Jaakko Helleranta.com" 

Sent: Jan 16, 2013 8:06 AM

To: Filip Rosenkranc 

Cc: hot at openstreetmap.org, dies38061 at mypacks.net

Subject: Re: [HOT] Central African Republic, use of landcover=bare_earth



HMm. For some reason having highway=track + area=yes doesn't sound right to me.

I'll comment on the road tagging separately with a bit better time but to me there are two problems:

- area=yes doesn't make the _area_ routable. All of your routes through this area (with the current routing engines, that is) would go via the boundary. .. This is not a problem for small areas. .. And the problem can be avoided by drawing ways through the area. .. But that's what you're trying to avoid here, right? 

- for some reason I find "track" a slightly difficult area road type tag. .. Track implies (to me) more or less rough surface and possibly 4wd_only. While I have no idea how the surface is in the linked area it just doesn't seem to fit well.


Did the idea of adding highway=track + area=yes to the landcover=bare_earth come from merely the attempt to avoid drawing tracks through the area?
Just my quick thoughts,

-Jaakko--jaakko at helleranta.com * Skype: jhelleranta * Mobile: +509-37-269154  *  http://go.hel.cc/about.me


On Wed, Jan 16, 2013 at 5:53 AM, Filip Rosenkranc <frosenkranc at gmail.com> wrote:


Hi,
I understand the problem - many tracks and paths going together to a space of bare land where they are no more recognizable.I have never used the tag landcover=bare_earth and couldnt find anything on the Taginfo either. 


I will be happy if anyone could check and share his view. The result on OSM is here: http://www.openstreetmap.org/?lat=6.539969&lon=21.977844&zoom=18&layers=M



Personally I think it is too much work, it will never be too precise (the level of greenness changess throughout the year) and it is not a priority in this first phase of TM mapping



SincerelyFilip from Eurosha CAR team


> I've added two instances of multipolygons for areas given the tags {{tag|landcover|bare_earth}} and {{tag|area|yes}} 


> in order to set apart cleared from non-cleared areas where the building density is low. > See http://www.openstreetmap.org/browse/relation/2683208 


> and http://www.openstreetmap.org/browse/relation/2682230 . > I'm considering adding {{tag|access|vehicle}} to these areas so that they explicitly complement the highway ways which connect with them.  


> Thanks for your thoughts on this. --ceyockey

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