[OSM-talk] [tagging] alley - for tree-lined roads?

Hillsman, Edward hillsman at cutr.usf.edu
Tue Nov 3 14:33:17 GMT 2009


>Date: Tue, 03 Nov 2009 12:54:32 +0000
>From: Robert <ropino at online.de>
>Subject: [OSM-talk] [tagging] alley - for tree-lined roads?
>
>Hello,
>
>We are discussing in talk-de (German board) just streets and other ways 
>with many trees nearby.
>
>I found here:
>http://wiki.openstreetmap.org/wiki/Tag:natural%3Dtree
>http://wiki.openstreetmap.org/wiki/Talk:Proposed_features/tree_row
>alley=left/right/both
>
>I think the tag ?alley? is a mistranslation (false friends) and
>1. avenue
>or
>2. tree-lined road
>is better for roads marked by trees.
>
>The tag alley is already used for highway=service; service=alley for 
>narrow ways.
>
>I think the second version ?tree-lined? or ?tree_lined? is better than 
>?avenue?.
>With this key we can use it for other lines of trees, for example near 
>railways, rivers and so on.
>
>At the moment this tag is probably only mainly used in Germany:
>http://osmdoc.com/de/tag/alley/#values
>comparison: http://tagwatch.stoecker.eu/Germany/De/tags.html
>key alley with values: both (251), right (27), left (26), yes (8)
>
>My questions:
>Would we like to change this tag?
>
>
>Robert

Hi Robert,

I posted the following on the tagging listserv last Friday, as part of a longer discussion. I would like to see the tagging separate the attribute (shade) from the feature itself (highway, footway, etc.). Most of what I wrote would apply more to sidewalks/footways than to streets, but the =trees option clearly would apply to streets as well. I want to get some photos to illustrate the application, and then post it as a proposal for comment. But I would welcome your suggestions before then

we want to develop a walking-route finder for students using 
wheelchairs. I've been considering proposing a tag shade=*, intended 
to apply to a sidewalk or street (mostly sidewalks, though), with the  
following values based on midday shading:

=trees, if the way is heavily shaded by trees (not intended for areas  
on a way shaded a single tree, but for a length of way with shade  
covering a substantial part of the length)
=pergola, if the way is covered by a pergola or similar trellis with  
plantings dense enough to provide shade
=roof if the way is covered by an awning or similar roof impervious to  
rain. Intended for a free-standing structure built for the purpose of  
covering the sidewalk
=building if the way hugs the north side of a building and is shaded  
by it (this would apply in latitudes farther north than here--in  
midsummer the sun is too high)
=portico if the way runs beneath a canopy, colonnade, or similar  
projection of the building that provides shade and shelter but,  
depending on the orientation of the way, might provide shade at noon  
and in the morning, but not in the afternoon (or vice versa). This is  
the value that I have been considering for the second case above  
(building on one side, grass on the other, second level overhead.  
Older parts of some European cities are full of these. Better-designed  
commercial developments also have extended awnings/canopies attached  
to the front of the buildings, shading the sidewalk that runs along  
the front of the shops.
=none would be the implied value if shade=* is not coded, although I  
would understand if a mapper coded it to make a point during a hot  
shadeless afternoon walk.
Maybe other values, but these are the ones I've encountered here, or  
thought about. shade=trees could apply to older streets as well as  
sidewalks, but I doubt the other values would apply to streets very  
often. Shade=trees would also apply to stretches of hiking paths  
(below treeline, obviously) and cycle paths, distinguishing them from  
stretches through meadow, rockfields, talus, etc. Useful for planning  
a hike.

Knowing about shade would allow the eventual routing application to  
trade off using a slightly longer shady route vs a shorter one without  
shade. Because of trees, we can't just tag shade in association with a  
building or architectural element.

Edward L. Hillsman, Ph.D.
Senior Research Associate
Center for Urban Transportation Research
University of South Florida
4202 Fowler Ave., CUT100
Tampa, FL  33620-5375
813-974-2977 (tel)
813-974-5168 (fax)
hillsman at cutr.usf.edu   
http://www.cutr.usf.edu






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