I never said anything about _not_ having some way to encode such default rules. 
In fact, if you look at my recent posts here, you will see that I specifically 
pointed out the current lack of such a schema as an issue that needs to be 
solved. I also pointed out that the lack of “permission” relations is another 
issue that needs to be solved. I’m directly affected by both of these as I’m in 
Queensland and “no u-turn at signal controlled intersections” is the law in 
queensland.

 

In regards to the wiki, while it may not be “gospel”, there are usually reasons 
for the statements there, especially with things that have been unchallenged 
for a long time and which had been discussed in detail before (you did bother 
to look at the iD issue I linked, right?) So as long as it isn’t case of recent 
drive-by-night wiki fiddling, some thought should be put into figuring out why 
that statement is in the wiki instead of simply disregarding everything.

 

Cheers,

Thorsten

 

From: Paul Johnson <ba...@ursamundi.org> 
Sent: Friday, 6 April 2018 10:12
To: Tag discussion, strategy and related tools <tagging@openstreetmap.org>
Subject: Re: [Tagging] no_u_turn restrictions for every entry/exit into a 
roundabout when the way is split because of physical separation?

 

On Thu, Apr 5, 2018 at 5:06 PM, <osm.tagg...@thorsten.engler.id.au 
<mailto:osm.tagg...@thorsten.engler.id.au> > wrote:

I tought it was obvious, but let me spell it out: such restrictions represent a 
default which we should be recorded somewhere (not necessary inside OSM) once 
and observed by data consumers, not by creating potentially 100000’s of 
relations to again and again encode the default behaviour.

 

Why not have a schema, in the data, for encoding this?  Maybe a relation with 
the outermost administrative area to which it applies...

 

 

 

 

 

 

This is exactly the problem that exists in Brazil, where u-turns back onto the 
same way at intersections are generally prohibited without any explicit sign 
allowing them, so some mappers add 4 no_u_turn at every single intersection 
node.

 

Please refer to: https://github.com/openstreetmap/iD/issues/2527

 

In fact, it is also reapet, IN BOLD, on the main relation:restriction page: 
https://wiki.openstreetmap.org/wiki/Relation:restriction

 

*         Don't map turn restrictions that are the default for a given 
jurisdiction and are not signed. It is much better to ensure that routing 
engines embody the regional rule rather than mapping every occurrence as a turn 
restriction. This applies particularly to unsigned U-turns in Brazil, where 
using turn restrictions will require hundreds or thousands of restrictions and 
micro-segmentation of all roads which in turn make editing data hard.

 

Again, this falls back on the whole "quoting the wiki as gospel" part that I 
initially beefed about. 

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

Reply via email to