[Talk-transit] Updating the NaPTAN bus stops in Birmingham
christoph at b3e.net
Tue Nov 17 21:35:20 GMT 2009
I plan to do an update of the NaPTAN bus stops in Birmingham to bring
them in line with the imports in the rest of the country. The update
will make the following changes:
1. All naptan:unverified=yes tags are changed to naptan:verified=no.
This will make maintenance of the colour schemes in Novam easier.
2. naptan:unverified=no tags are removed. I think this makes more sense
than replacing them with naptan:verified=yes.
3. naptan:AdministrativeAreaRef tags will be removed as they have only
been used in the Birmingham import and nowhere else. So the tag is
quite useless (tagwatch lists 105 as the only value for the tag).
4. naptan:Bearing tags will be added to all NaPTAN stops that do not
have them yet (i.e. the stops in Birmingham).
5. naptan:BusStopType=CUS will be added when available and not yet
I am currently making the finishing touches on the import script and
will test it then. So, if there are no objections against the changes
the update should ready to go ahead in a couple of days.
Method used for the update:
I extracted atco-code, bearing, and bus stop type with an xsl script
from the NaPTAN xml file for the West Midlands and placed the data into
a new table in the Novam database.
Since Novam maintains an up-to-date extract of all bus stops in OSM the
bus stops which need be updated can easily be selected and joined with
the new data in the table created before.
Finally, a python script goes through the selected bus stops, applies
the modifications outlined above to each them, and uploads them through
the python osm api to OSM. If the upload fails due to a version conflict
the latest version of the bus stop is retrieved from OSM and the script
changes this node and uploads it again.
The scripts are currently tailored to add and remove some tags from the
Birmingham bus stops. However, I think this update might be a helpful
step towards more complex updates of the NaPTAN data in OSM.
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