[OSM-talk] Cycle route improvements

[Ben Laenen]

On Tuesday 05 February 2008, Andy Allan wrote:
> We have ncn= yes / proposed and this could easily be extended to ncn
> = yes / proposed / connection / alternative / no without adding any
> more tags. I'm not sure if anyone will care too much about
> proposed-alternatives being different from proposed-main-routes, but
> this wouldn't be hard to solve anyway.

All the better if there's an existing tag already, but how does that 
work with current tagging, I thought it 
was "type=route", "route=bicycle", "network=ncn", and will this be 
another tag "ncn=yes|proposed|etc"? Isn't the "ncn=yes" redundant 
information then?

> >  but in lower zooms it gets messy since it's
> > apparently a random one that "wins" for each section.
>
> That's a bug. It's actually deterministic, but I think what you're
> seeing on some parts is things like the end of the wider line
> overlapping with a different section. But I haven't sorted it yet.

I see this: 
http://www.gravitystorm.co.uk/osm/?zoom=12&lat=6652000.91116&lon=496400.42424&layers=B00

It looks random to me, but it could be "deterministic chaos" of 
course :-)

> My preference would be to draw the lines side-by-side, but that's
> what I'll call the "tube map problem" since mapnik can't do that.

That could work as well of course, though it looks much harder to 
implement compared to the wider vs thinner lines... But it could be a 
problem when there are lots of routes running in parallel (like the 
opposite sides of a canal or a dual carriageway even).

> It's common for routes to be distinguished on signs by colour as much
> as name or reference. I think they should be mapped with
> signed_colour = yellow, since that makes it clear. Renderers can then
> know that the colour is important, but still choose to ignore it if
> they wish (or map the colours to a chosen palette, or keep all the
> local routes in blue and put little coloured borders on them or
> similar). Using "signed_colour" clarifies what we mean.

I see, I was trying to avoid real colour names, but I guess we could 
further extend this colour tag to things like bus routes. I don't like 
signed_colour though, as that suggests that it's the colour of the 
signs, and I could well see someone adding "signed_colour=green" for 
all ncn, rcn and some lcn routes, since all those signs are green.

I'd keep signed_colour only for when the colour really matters and 
should be displayed in that colour as well (like mountain bike routes 
over here, bus lines, subway lines etc). And another tag for the colour 
alternates which I was talking about.

> That's a bug. Fixing it will also stop people using
> ncn_ref=Something-awfully-long-that-isn't-a-reference-really, which
> suggests the invention of an ncn_name= tag.

I just use "name=X" for that currently (since it's the relation that has 
this name tag, not the road, but don't ask me how to put that name on a 
starting point, could the starting point be a member of the route 
relation as well?)...

Ben