[OSM-talk] Cycleways wiki doc enhanced

[Lester Caine]

Richard Mann wrote:
> Drawing separate ways for cycleways/footways alongside roads is nice and 
> simple. Doing it with tags on a single way is about 5 times more complex 
> to tag, but tolerable, and potentially a lot easier to render well. 
> Doing it with areas is maybe 100 times more complex to tag, and cannot 
> replace the simpler methods (unless you want to make good rendering much 
> much more difficult).
Rendering at what zoom level?

> So shout as much as you like, but (IMO) areas are not going to catch on.
Actually I'm not 'shouting for' areas ...
However being able to ADD area data to a way or any other element is something 
that just needs handling. Attaching a set of areas that define the fine detail 
for a higher level structure is not about 'catching on' but rather about 'making 
provision for'. So that the actual area covered by a structure can be added 'if 
people want to'. My potential users are council departments who would be more 
than happy to ADD this level of detail if they are not ALSO paying a license to 
use it ( i.e. paying Ordnance Survey so they can use data THEY have created in 
the first place! ) And if we can get OSM used as a base for the National Land 
and Property Gazetteer, then everything in the UK would be available in fine 
detail ;)

> And, if there's a simplistic drawing of separate ways to mark cycleways, 
> then yes they probably will get converted into tags on the road, just as 
> soon as that renders properly. Rendering gain trumps notional 
> information loss. The Danes are just ahead of the curve.
Tags are never going to provide the level of detail required when zooming into 
lower levels, so while they are adequate shorthand at some levels, they need to 
be AUGMENTED with the actual details on the ground. While merging data at one 
level may tidy one perceived problem, it does not address the need to include 
more detail at higher levels? Getting the rendering to guess how multiple 
elements should be laid out at a high zoom level is just another problem to 
solve ... which is the same discussion we have had with bridge and tunnel 
structures and complex motorway interchanges. At some zoom level 'it would be 
nice' to render the reality on the ground, rather than the renderer's shorthand 
for that?

Perhaps we do need to fork the project and create openmap.org so we can get away 
from a fundamental belief that 'the road rules'? But all I am 'shouting for' is 
that there are hooks to maintain a hierarchy of detail as one moves from a macro 
to micro view. If people only want a 'road map' or 'cycleway map', then that is 
not a problem, but it should not then prevent the fine detail from being 
maintained below it?

-- 
Lester Caine - G8HFL
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