[Talk-transit] NaPTAN data import

Thomas Wood grand.edgemaster at gmail.com
Fri Mar 6 17:38:26 GMT 2009


2009/3/6 Brian Prangle <bprangle at googlemail.com>:
> Hi everyone
>
> We discussed at our West Mids meeting last night the best way forward. Here
> is what we would like to see happen:
>
> 1. Proceeed with the import on the basis of the proposed naptan taggings.
> All imported data should have the naptan: prefix as we feel  it is important
> to identify the source of the data and differentiate it from OSMer-generated
> data
> 2. If it's easy to code,  generate ways between related nodes for things
> like plusbus zones, stopareas etc. We didn't discuss however how to tag
> these, so I guess just leave them untagged. If it's going to be difficult
> and slow down the implementation, then ignore it and just import the nodes
> and we'll have to generate ways manually.

StopAreas are very common in the London data that I've been testing
against, as noted in previous emails to the list, the converter does
convert the majority into relations. The only issues I'm having with
it is trying to keep list of the national StopAreas. I should tackle
this problem sometime this coming week.

I guess a relation for a plusbus zone will also probably be good, a
polygon can be derived from it automatically, I think we'd have to
invent a new, creative relation scheme, since a stop area relation
doesn't suit it well.

> 3. Rather than import for the whole West Midlands, just import for
> Birmingham as a test area - it's easier for us to cover as there fewer bus
> stops in a smaller area, and it also won't piss off our neighbours in
> Coventry - most of us are based in Birmingham.

That's fine, I think I'll add a bbox filtering option.

> 4. The import should not tag the data with highway=bus_stop. We'd rather
> have un-rendered nodes that we can see in the editors and then either merge
> with existing data  or "switch on" by tagging where we haven't yet surveyed.
> It is OK however to tag taxiranks with amenity=taxi (very few people have
> been surveying and tagging these)

I can just flip these tags fairly easily, so isn't much of a problem.

> 5. Can we have a csv file of the data so we can keep track of our
> verification and record variations, problems on the ground etc. and
> co-ordinate activities so we don't go off duplicating effort?  In the future
> other OSMers will have the benefit of Christophe's visual tool to do this.
> We'll give regular updates here on how we're faring and produce a short
> report summarising our experience for future imports.

A csv file of the data, can you be more specific on _what_ you mean by data?
The wiki is an excellent place for coordinating tidy-up projects.
Notes on changes can be stored on the nodes themselves, if suitable,
otherwise we'd need an annotation tool with Christophe's visual tool.

> 6. As a local initiative we are proposing to cease using (and convert
> existing data) the ref=xx tag for identification plates we find on the
> ground as it doesn't currently match any naptan data (and so can't be
> regarded as a global standard reference) and we will use instead
> asset_ref=xxx. This is Andy's suggestion and as he's the one who's entered
> most of this data and he'll have to do most of the work - we all agreed
> readily!

Do we now want to import any suitable asset_refs (from whatever the
equivalent field is called) from naptan, where they exist (most suited
for other regions)?

>
> Let us know if there are any problems with this
>
> Regards
>
> Brian

Regarding Peter's comments about obtaining the data, I'm already
getting it from the official site for testing the converter, since the
license they give there allows it explicitly.

Regarding the data import more generally, do we have a rough timeline
of when we want this done by?
We should probably avoid the 0.6 and licensing changes, so we don't
create more work for ourselves than is absolutely required.

Gerrit - NaPTAN references nodes as being part of a StopArea, somewhat
like our relation structure. The converter is already pulling them in
according to the unified stop area spec. (Except for not having the
stop-points on the road way, just beside, but thats just a moot point)

-- 
Regards,
Thomas Wood
(Edgemaster)




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