[Talk-transit] GTFS from OSM data?

Khoa Tran ktran9 at mail.usf.edu
Tue Aug 30 02:00:54 BST 2011


Mike,


I'm the developer of GO-Sync. Glad to hear that it's useful for you.
Regarding the issue of building GTFS data from OSM, my mentors and I had a
small discussion and we identified the following challenges:


1) routes and trips have a 1-to-many relationships. In other words, a route
can have many different trips that visit different sequences of bus stops on
that route, all dependent on different schedules.  We can get a list of all
the routes in the region by getting all relations with route=bus in the
bounding box. However, given that OSM doesn’t have a clean way of storing
schedules that would be required for creating trips.txt, we feel it’s better
to store/generate this data outside of OSM.  In other words, GO-Sync could
be used to manage bus stops for stops.txt and routes for routes.txt and
output this data to GTFS format, but trips.txt and shapes.txt would be
significantly more difficult (because they are attributes of trips and
schedules).****

** **

2) Shapes.txt file requires "shape_pt_sequence", which defines an ordering
of stops within a trip.  If I understand your question correctly, you want
to represent this information in a ‘public_transport=stop_position’ tag on
the route relation.  I believe this would be possible, but you would still
need to deal with the issues of schedules and trips as discussed in #1
above.****

** **

Having stated the above challenges, we made the source code publicly
available and we welcome any suggestions and contributions to the project.
If you’re able to overcome the above challenges and create a tool based on
GO-Sync that is useful to you and others, we’d be glad to review this tool
for possible inclusion in the GO-Sync Google Code repository so it can be
shared with others.****

** **

You also might want to check out a recent webinar by the National RTAP on
their GTFS Builder Tools:****

http://www.nationalrtap.org/Resources/VideoLibrary.aspx****

** **

As well as the Transit Data Feeder project (
http://code.google.com/p/transitdatafeeder/), which is an effect to develop
and maintain an application that provides a web-based interface for creating
and maintaining GTFS feeds.****

** **

Feel free to contact us if you have more questions.

On Fri, Aug 26, 2011 at 9:05 AM, Mike N <niceman at att.net> wrote:

> I have looked at Go-Sync (Great tool!) and have some questions about public
> transport and GTFS.   I am starting from perhaps the reverse of normal case:
> any agency data on routes and stops was way out of date and very incomplete.
>   The system is small and well within the scope of being surveyed from
> scratch and entered into OSM. It appears that Go-Sync is focused on stop
> synchronization, given the routes in routes.txt+trips.txt+shapes.**txt .
>
>  1.  Are there any tools to create routes.txt + trips.txt + shapes.txt from
> OSM public transport route relations?   If not, would such a tool be within
> the scope to add to Go-Sync, or should this just be a separate tool?
>
>  2.  For bus routes, is there any value to adding
> public_transport=stop_position to the OSM data, in addition to
> highway=bus_stop?
>
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>



-- 
Khoa Tran
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