[Tagging] Is a sidewalk always adjacent to a traversable road?

[Anthony]

On Thu, Aug 25, 2011 at 7:50 AM, Simone Saviolo
<simone.saviolo at gmail.com> wrote:
> 2011/8/25 Anthony <osm at inbox.org>
>> That's what's said, anyway.  Personally I've always considered it
>> false to say that these two lanes aren't physically separated.  Those
>> lines drawn on the ground aren't figments of my imagination.
>
> I can understand the arguments: after all, you can physically go from a lane
> to the other with your car, so they aren't physically separated.

I can physically go from one carriageway to the other with my car as
well, though.  And why should my car be the only vehicle which
matters?

> Personally, I'm in favour of drawing two distinct ways.

It's a tradeoff.  Neither drawing two distinct ways, nor drawing one
way, works in all situations, at least not given the currently widely
accepted tags.

It's fundamentally a 2 dimensional situation being forced into a 1
dimensional mapping system.