[OSM-newbies] cycle map rendering

[Dave Stubbs]

On Tue, Sep 8, 2009 at 7:27 PM, Alex Mauer <hawke at hawkesnest.net> wrote:
> On 09/07/2009 01:51 PM, Richard Fairhurst wrote:
>> can use any tags you like. But from the outside, there doesn't seem to
>> be any huge agreement on how it's used (I mean, what is this
>> 'designated' shit?),
>
> Conveniently, there's a wiki page dedicated to documenting it:
>
> http://wiki.openstreetmap.org/wiki/Tag:access%3Ddesignated
>
> It’s even pretty
>
>> and so the render rules are going to have to be
>> really complex to cope with the many possibilities.
>
> (highway=path AND bicycle=designated) OR highway=cycleway => Render like
> a cycleway.


last time I tried to figure this out the rule ended up looking a bit like:

([highway] = 'path' and ([bicycle] = 'designated' or [bicycle] =
'yes')) or [highway] = 'cycleway'

then i had to modify the foot path rendering as well

(([highway] = 'path' and ([foot] = 'designated' or [foot] = 'yes') and
[bicycle] <> 'designated' and [bicycle] <> 'yes') or [highway] =
footway

then we have cycle bridges of course so:

(([highway] = 'path' and ([bicycle] = 'designated' or [bicycle] =
'yes')) or [highway] = 'cycleway') and [bridge] <> ''
altering the original to not match bridges
(([highway] = 'path' and ([bicycle] = 'designated' or [bicycle] =
'yes')) or [highway] = 'cycleway') and [bridge] = ''

and the foot bridges become:

((([highway] = 'path' and ([foot] = 'designated' or [foot] = 'yes')
and [bicycle] <> 'designated' and [bicycle] <> 'yes') or [highway] =
footway) and [bridge] <> ''

You can see how this blows up out of any maintainability quite
quickly, especially with the proliferation of 'yes' values since the
original highway=path proposal (I think, I wasn't following too
closely). And to boot I wasn't even sure that those were correct.

And that's why it's not been done. Obviously our stylesheets/data
processing (we're using the original mapnik stylesheet syntax) needs
to work in a different way to cope with all this -- but getting that
done is a lot of work.

It's not a huge personal priority as I don't think I've ever used the
highway=path tag, not for a cycle related route at least.

Oh, incidentally.. someone mentioned on here that MTB routes aren't
rendered, now I can't find the post... -- that's not stricting true --
way way way back in the day I added a few in wales with a route
relation route=bicycle, network=mtb .. probably not the best tagging
in the world but the cycle map does render them.. look!:
http://www.opencyclemap.org/?zoom=12&lat=52.55544&lon=-3.79561&layers=B000
Unfortunately we added hillshading since then so the green doesn't
really work, but hey ho.

Dave