[OSM-talk] Downloading Version 3 of all bus stops in a country

[Jo]

Hi Safwat,

Overpass API is definitely your friend. Version 3 doesn't mean much though.
Do you mean all bus stops with a public_transport tag?

I would go about it in a slightly different way and download everything
related to public transport, not just the stops using the query found on
this page:

https://wiki.openstreetmap.org/wiki/JOSM/Plugins/PT_Assistant/Mapping_Public_Transport_with_JOSM#Downloading_data

Then load that in PostGIS and create scripts to read GTFS into PostGIS.

Then compare the data in the DB and produce output and ideally a UI.

I started doing something like that here:

https://github.com/osmbe/public_transport

Let me know if you see ways of working on that or another way to tackle the
problem together.

Jo

2017-09-26 9:19 GMT+02:00 SwiftFast <swiftfast at gmx.com>:

> I need to download all version 3 bus stops in a country which has about
> 30,000 bus stops. Version 3 exists since a 2012 import. What's the
> recommended way to accomplish this? I have two ways in mind.
>
> 1. Fetch all stops with Overpass API, then, for each
>    stop id, fetch version 3 from the main API.
>    - Pros: I already know how to do that
>    - Cons: Potentially too much load on the OSM server.
>            Will I be rate-limited?
>            Requires some script writing which could take
>            more time than the way below.
>
> 2. Download a history-supporting planet file,
>    and extract the desired bus stops through Osmosis.
>    - Pros: Less API load
>    - Cons: I'm not sure what the proper Osmosis commands are,
>            and if this  is a supported operation. Also, I need
>            to download a big file (the oldest history supporting
>            import is 40GB from 2013).
>
> 3. Other suggestions?
>
> Why I need this:
>
> I am creating a script[1] for incrementally updating GTFS imports.
> It'll initially be used in Israel but it can be adopted worldwide. We
> have an import from 2012 which was "dumped and forgotten" and is now
> very stale. I want to forever fix this.
>
> The ministry of transportation publishes new GTFS files daily. My
> script compares an older GTFS file with newer one, and only updates the
> bus stops that were changed/added/deleted. The idea is to feed it a
> newer GTFS database daily or weekly. However, I do not possess the file
> that was used in the 2012 import, so, in order to bootstrap the script,
> I need to recreate that file from the old OSM data.
>
> [1] https://forum.openstreetmap.org/viewtopic.php?id=16738&p=3
> (note: SwiftFast and SafwatHalaby are both me)
>
> Thanks in advance.
>
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