Use GTFS data for transport platform, area, route and route_master

[sidjy]

Manu public transport operators publish GTFS open data (for exemple STIF https://opendata.stif.info/explore/dataset/offre-horaires-tc-gtfs-idf/information/ ). As it is a technical standard, it would bé useful to implement a parser in osmose back-end, so we can integrate at least transport platform and area easily for manu PT operators worldwide (for stop, route and route_master it is more difficult as we need to find the nearest way, and the used way segments). We need a convenient key between GTFS and OSM, perhaps a gtfs_id or ref:GTFS key?

[frodrigo]

A GTFS is just a CSV in a ZIP. If no join on the CSVs is required we can already do this.

[sidjy]

Indeed, we need some type of join on the CSV...
We can imagine some preprocessing on the GTFS/zipped CSV files to produce "ready to use" CSV files for osmose...

• routes.txt list the different lines of PT (all bus/rail/metro lines/...), equivalent to type=route_master OSM relation.
• Foreach line, trips.txt lists all the different trips, equivalent to type=route OSM relation.
• Foreach trip, stop_times.txt lists all the different stops, equivalent to OSM public_transport=platform.
• Foreach stop, stops.txt gives lat/lon coordinates and the name of the stop (public_transport=platform).

Directly parsing stops.txt without join can be done, but we loose some useful informations : we know it is a transport platform where passengers board or disembark from a transit vehicle, its name, its id, and its location, but we do not know which lines use it (and which type of PT : is it bus/rail/metro???). Is it enough to be useful ?

Note : there are realy many GTFS feeds around the world, see here : https://transitfeeds.com/about
Of course, quality of data will vary, but it would be useful to help integration of PT in OSM.

[frodrigo]

In fact I found two analysers already based on GTFS
https://github.com/osm-fr/osmose-backend/blob/master/analysers/analyser_merge_public_transport_FR_transgironde.py
https://github.com/osm-fr/osmose-backend/blob/master/analysers/analyser_merge_railway_railstation_FR.py

[frodrigo]

TrasitFeeds does not seem to provide data licence.

There is also https://navitia.opendatasoft.com and they provide a licence field in metadata.

[frodrigo]

@sidjy @nlehuby stops.txt from GTFS should be platform or stop position ?

[nlehuby]

The GTFS format puts no constraint on that : the GTFS stop is a logical stop (whereas OSM ones are physical ones). A GTFS stop can be a platform, a stop_position, or even the center of the stop area.
If you have a stop served by 3 bus lines, you can have 1 GTFS stop, 3 GTFS stops, but even 2 GTFS stops 😕
So you have to analyze the GTFS modelization to determine what to do precisely with the stops.
I think for the buses, stops are mostly platform or center of stop area, whereas for trains, they are mostly stop_position

You have the same fuzz with the routes : they are a group of trips so they can be lines (type = route_master), but they also can be just routes (type = route) or group of routes (nothing in OSM).

[sidjy]

A good solution would be to let the user determine if it is a platform or a stop_position. A good hint for bus is the distance to nearest route: for most cases in Ile de France GTFS stops for busses are platform. Le 20 juin 2017 8:12 AM, "Noémie" <notifications@github.com> a écrit :

…

The GTFS format puts no constraint on that : the GTFS stop is a logical stop (whereas OSM ones are physical ones). A GTFS stop can be a platform, a stop_position, or even the center of the stop area. If you have a stop served by 3 bus lines, you can have 1 GTFS stop, 3 GTFS stops, but even 2 GTFS stops 😕 So you have to analyze the GTFS modelization to determine what to do precisely with the stops. I think for the buses, stops are mostly platform or center of stop area, whereas for trains, they are mostly stop_position You have the same fuzz with the routes : they are a group of trips so they can be lines (type = route_master), but they also can be just routes (type = route) or group of routes (nothing in OSM). — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#163 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ALG88nUScEhbkBQyqSogeL9rsCPrX8oIks5sF2K4gaJpZM4LFsrl> .

[frodrigo]

We do it with stop. The others can't feet easly in Osmose.