[Tagging] Highway property proposal "covered=yes"

Randy rwtnospam-newsgp at yahoo.com
Mon Nov 2 04:55:44 GMT 2009


Martin Koppenhoefer wrote:


>
>>I think "underground" is an unfortunate qualifier on tunnels, and I'd like
>>to see it removed.
>
>
>no.
>
>
>>First of all, it's inaccurate. Look at the online
>>dictionaries.
>
>
>no, don't look at "online dictionaries" when talking about technical issues
>that are well defined. IMHO the online dictionaries are inaccurate at this
>point.
>
>
>>Secondly, if adopted strictly, if forces the creation of a
>>separate tag with identical functionality for the above ground case.
>>
>
>Which does make sense. A tunnel going underground can be crossed mostly
>without even noticing the tunnel while a street that is covered or inside a
>tube at groundlevel will mostly be an uncrossable obstacle, so that the
>impact of this difference is huge! The functionality might in some cases be
>identical for who uses the tunnel / street, but it is not for the rest.
>
>cheers,
>Martin

Obviously, I agree with Anthony that if it is necessary, layers can be 
used to address the crossable issue. But, it seems to me that overpassage 
of the tunnel itself is rarely, if ever, an issue. Even accepting that a 
tunnel is above ground, it has to go through something. The issue is 
whether you can cross over the object it goes through, not the tunnel 
itself, unless I'm missing something.

But, assuming we only allow tunnels to be underground, how would you 
propose tagging a passage open to the outside at both ends, going through 
a building that has no side portals into the building?

I did look up the definition of tunnel in my Webster's Unabridged, and 
will concede that, that particular dictionary did seemingly restrict it to 
underground. However, in the verb form it defined creating a passage under 
or through something. So I guess if you tunnel through an above ground 
object you are creating something other than a tunnel. That's supposed to 
make sense?

Meanwhile, we probably should re-lable this thread if we take the tunnel 
issue much further. I'm more interested, in this thread, in resolving 
whether or not there is a consensus on adding a "covered" tag for ways 
(including, but not necessarily limited to the various values of highway) 
that, in general, at least, proceed under or through a structure in such a 
way that it is inappropriate to tag them at different layers than the 
object they are passing through, without going to a whole new complex 
three dimensional mapping schema.

If there are no serious objections, I will add a new entry to the 
Properties sub-section of the Map Features page (which although it is in 
the Non Physical section of the page contains numerous physical 
properties), after which I would welcome any appropriate tweaks to the 
definition.

-- 
Randy





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