[Talk-GB] Cycle lane in one direction only

[Gregory Williams]

> -----Original Message-----
> From: talk-gb-bounces at openstreetmap.org [mailto:talk-gb-
> bounces at openstreetmap.org] On Behalf Of Andrew Chadwick (mailing
lists)
> Sent: 30 September 2008 15:29
> To: talk-gb at openstreetmap.org
> Subject: Re: [Talk-GB] Cycle lane in one direction only
> 
[Snip]
> 
> We'll probably have to introduce a new tag to say on which side of the
> road the cycle lane(s) lie, relative to the direction of the way's
> arrow. What about adding something like:
> 
>    cycleway:left=<any value permissible for cycleway>
>    cycleway:right=<any permissible value for cycleway>
> 
> and stating explicitly that the existing cycleway=* definition still
> means both sides: cycleway=FOO would imply both cycleway:left=FOO and
> cycleway:right=FOO.

That seems sensible to me. It's something I've been wondering about as
well. I'm aware of several places where there is a cycle lane only on
one side of the road. For the moment they're tagged as if there is a
lane on both sides.

Now we need to be able to render something like that. As noted in the
comments on Andy Allan's blog post about rendering cycle lanes [1]
Mapnik doesn't support rendering offset from the centre of a line. I
think the same is true for Osmarender? I guess that it would be possible
by manipulating the geometry accordingly in the Postgres query for
Mapnik (though a tremendous hack).

Gregory