[OSM-talk] routing across open spaces

[Anthony]

On Mon, Dec 6, 2010 at 3:56 PM, Dave F. <davefox at madasafish.com> wrote:
> On 05/12/2010 22:07, Anthony wrote:
>>
>> On Sun, Dec 5, 2010 at 11:03 AM, Dave F.<davefox at madasafish.com>  wrote:
>>>
>>> As long as there are external ways connecting  to the area, a router
>>> should
>>> be able to find the appropriate entrances&  exits by tracking the
>>> perimeter.
>>> I thought they were already able to do that, but maybe not.
>>
>> Surely they can - just treat it like any other way.
>
>
>
>>   However, they
>> don't treat leisure=park as a routable feature
>
> All routers? All areas?

My understanding is that routers just ignore the area tags completely.
 So as far as the router knows, so a closed way marked with
highway=residential/area=yes is treated exactly the same as any other
way marked highway=residential.  In other words, it routes along the
perimeter, and not through the area itself

So allowing routing around the perimeter of an area marked
leisure=park would simply require treating leisure=park the same as,
say highway=pedestrian.

Not that I think this is a good idea.  It probably isn't.  But it's
certainly possible.

>>  - which, if all they
>> know about is the perimeter, is probably a good thing.
>
> Eh? I thought you said you'd "love it" if it cut directly across an area??

No, I didn't.

> They don't have to *follow* the perimeter just use it to find the best exit
> & then join it to the entrance to the area with a straight line.
>
> Are you certain no routers can do that?

Of course not.  I'm not even certain I know of all routers that exist.