[Talk-ca] Geobase NRN import script

James Ewen ve6srv at gmail.com
Fri Jan 2 05:13:48 GMT 2009


On Thu, Jan 1, 2009 at 5:28 PM, Jason Reid
<osm at bowvalleytechnologies.com> wrote:

> In terms of actually adding the data into OSM, the only real solution is to
> use the API and the bulk_upload tool (or a tool with equivalent
> functionality).

But that bulk_upload tool has no provisions for checking for and
possibly matching existing ways, correct?

That's the part that needs to be developed. We pretty much have the
tools and capabilities of taking an existing database, and converting
it into OSM style data. It's the merge with existing data that's the
part that needs attention.

> The tagging will be the single largest issue of contention, not only for the
> upload but for applying updates in the future as well. Take your example of
> Highway 2 for instance. If we upload it as it is in Geobase (which works out
> to be a primary highway I believe), but then you correct it to be what you
> think it is (for instance, highway=motorway), then the update script comes
> along and sets it back to primary, theres the potential for a bit of
> disagreement to take place.

Actually the script currently assigns Highway 2 a trunk status simply
based on ref ==2, but trunk isn't in the wiki attribute translation
page, and according to the OSM description, it is a motorway for quite
a distance south of Edmonton. This is where the merge tool becomes
very important. Anywhere that existing data is found, you're going to
need to have some way of resolving the discrepancy. Most likely it's
going to take some human intervention. The tug-of-war back and forth
between scripts and user needs to be avoided.

> Theres a lot of other cases I've already seen
> where the tagging will be modified, in some cases its where the tagging
> guidelines are tagging for the renderer, or just where the OSM
> classifications don't fit the real world (take part of Highway 40 north from
> Highway 3 for instance, I believe Geobase has it as a Expressway / Highway,
> however in reality its a 2 lane gravel road winding through the mountains
> that in OSM is also tagged as a highway=primary).

Well, according to the government, Highway 40 is a primary highway...
it just happens to have a surface=gravel. Around Hinton, you can get
on some forest service roads that are wider and smoother than Highway
40, but if you tag them as such using the OSM guidelines, you would
think they are tire ruts in the back woods. It's pretty tough to try
and accurately represent the real world with generic tags.

James
VE6SRV




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