On 08/12/2010 21:59, Steve Bennett wrote:
So the question arises: does the community support this view?
Unlike the Life of Brian, here everyone does seem to be an individual -
I suspect that you'll get as many answers as there are mappers.
Speaking entirely personally, I do mostly only map places that I've been
and don't tend to trace e.g. a road or track unless I've seen one end of
it. When I started adding stuff to OSM the map was entirely blank where
I lived and I wasn't aware that anyone traced stuff at all. I
eventually encountered a road that seemed a bit wrong - it was
consistently a few metres SW of my GPS traces. Initially I assumed that
I must be hitting some sort of "urban canyon" effect and tried again,
but got the same results. Eventually I figured that it had been traced
from an old NPE (out of copyright) map. There was actually nothing
wrong with the tracing; the error was on the old map.
So was the original mapper wrong to have traced that road from NPE?
Personally I'd say no; a road in not quite the right place (on an
otherwise empty map) is better than no road at all. Problems can
obviously happen if what's being traced from isn't as good as it could
be (the issue that Kenneth raised earlier on in the thread), and in the
UK that may be an issue with some of the Bing imagery as it looks (a)
quite detailed but (b) quite old.
Where there are a reasonable number of local mappers, tracing can be
less beneficial because it can get people to think that an area is
"complete" when it's not been ground surveyed. When creating Garmin
maps locally for my own use I try and incorporate certain "source="s
(e.g. "NPE", "Yahoo") and users (if a known non-on-the-ground mapper) in
the name. I live not far from Staffordshire in the UK and parts of that
are somewhat iffy - they look complete, but what's on the map doesn't
match reality. However, there are also places where a GPS simply won't
get a good fix because of the terrain and short of a theodolite or
something capable of dead reckoning, tracing is the only way to get an
accurate road / path layout to lay POIs on.
If you're in a country with relatively few mappers, then tracing makes
some sense, it gets coverage now where there otherwise would be none,
but it doesn't take away the requirement for someone (eventually) to
visit and add detail that you can only get by actually being there. I
don't think that there can ever be a planet-wide consensus about tracing
where you haven't visited; but individual communities should be able to
come to some sort of agreement for smaller areas.
Cheers,
Andy
_______________________________________________
talk mailing list
talk@openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk
