[Tagging] Micro mapping traffic signals

Peter Wendorff wendorff at uni-paderborn.de
Wed Aug 28 07:02:53 UTC 2013

Am 27.08.2013 17:38, schrieb Pieren:
> On Tue, Aug 27, 2013 at 5:15 PM, Peter Wendorff
> <wendorff at uni-paderborn.de> wrote:
>> It's more reliable to guess the direction by
>> nearest-distance-to-next-intersection than to rely on any mappers to
>> keep that up to date, especially with iD making it extremly easy (which
>> is good) to change a ways direction.
> This was also my argument in the past. But you still have cases where
> it's not 100% reliable e.g. when the node is between two
> intersections.
Sure, but the reliability is not better when the data promises to be
more reliable, but mappers tend to produce errors by reverting ways
without any chance to get information about potential problems there.
>> Now your node is part of two ways - and what now?
> The attribute is about traffic signals, you can safely ignore the
> pedestrian way (until traffic signals will be common for
> pedestrians...) 
okay, agree - this is detectable, as it matches on nodes where the
cycleway/footway in fact crosses the street.
What about cycleways? There are traffic signals for cycleways.

> If the tag is placed on a real intersection node, we
> can consider this as a mapping mistake and fallback to the old fashion
> of mapping traffic lights. 
Maybe, yes.

> But again, I'm not here to defend this tag
> but to propose a replacement by a relation.
>> Another example: the way ends at your node on both sides - and both ways
>> go to different directions - and now?
> First, this can controlled by a QA tool and fixed.
What's wrong with that?
It's a totally valid mapping situation, as long as the idea with
direction on nodes is (as it is yet) not the common tagging proposed,
e.g. because there are many errors that may occur out of this idea.

> Second, read my OP. My proposal is to replace this direction on node
> by a relation...
I didn't want to offend your proposal, but give arguments why the
direction-on-node variant is a bad idea. I have no idea why that offends
you (at least partly), when it's neither your idea nor your favourite.


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