[Tagging] How to tag: Legally separated ways

[Tobias Knerr]

Am 17.10.2012 00:18, schrieb Anthony:
> On Tue, Oct 16, 2012 at 9:30 AM, Tobias Knerr <osm at tobias-knerr.de> wrote:
>> On 16.10.2012 01:07, Anthony wrote:
>>> As long as you have width information on the ways, I don't see the
>>> problem.  The amount of physical separation, whether it be an inch
>>> between two lines, or a meter, should be easily calculated from the
>>> data.
>>
>> There are actually several problems:
>>
>> * Most importantly, neither width tags nor the distance between two
>> parallel ways are mapped with one-inch accuracy.
> 
> If this is the most important, then you are seriously stretching it.
> What's the need for one-inch accuracy?

You suggested that "the amount of physical separation, whether it be an
inch between two lines, or a meter, should be easily calculated from the
data."

I'm saying a separation of an inch between two lines can _not_ be
calculated from the data because it's not remotely precise enough, and
shouldn't be expected to be.

>> * If you represent the two lines as a separation between ways, then you
>> don't know that the two lines are there - so you cannot render them.
> 
> I'm not sure what this means.  The ways don't represent lines, they
> represent paths of travel.

In my statement above, "the two lines" refers to the road markings.

> There are lots of paved surfaces which are not mapped.
[...]
> Furthermore, what do you suggest we do with section 6

If someone cares about the surface of an area which is not part of any
highway, they can map it as an area with surface=*.

This does not seem like an appropriate solution for the tiny "area"
between two white lines of paint, though.

Tobias