[OSM-newbies] Validation Error

[Mike N.]

For no-turn intersections in terms of the map data, it is correct to just 
ignore the error since routing will be correct.   The only reason to put in 
intersection nodes plus turn restrictions would be so that following mappers 
don't blindly fixup validator errors by just joining the 2 ways.

 A NOTE tag to other mappers placed on the ways might be a better solution.

   I find turn_restriction relations to be extremely complicated (perhaps 
overly complicated, but I don't have a simpler way offhand).   A simple "no 
left turn allowed" T intersection tuned into an extra split for the way at 
the T, followed by 2 turn_restriction relations to cover the simple case. 
I'd hate to model this for a more complex intersection.

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From: "James Ewen" <ve6srv at gmail.com>
Sent: Saturday, January 30, 2010 11:55 AM
To: <newbies at openstreetmap.org>
Subject: Re: [OSM-newbies] Validation Error

> On Sat, Jan 30, 2010 at 4:24 AM, Mike N. <niceman at att.net> wrote:
>
>> Normally crossing ways indicate an intersection in which vehicles can 
>> move
>> from one way to the other way.
>>
>>    If some turns are not allowed due to posted signs,
>> then "turn_restriction" relations should be added as required.
>
> If you have two ways crossing, where the turn restrictions are no
> turns for both ways, why would you create an intersection on those
> ways?
>
> It seems a little counter intuitive to be putting intersections where
> the roads don't intersect (allowing choices in direction of travel),
> but simply cross (no choice in direction of travel) each other.
>
> I'm guessing that you would just ignore the error then.