[Open-transport] Open Transport Data tools / webservices

Mon Jul 15 16:27:32 UTC 2013

On 07/15/2013 11:06 AM, Tristram Gräbener wrote:
> Now to the vocabulary: I have a feeling that there is an agreement that
> the Transmodel vocabulary is quite good (opposed to the GTFS one which
> is too simplified). Maybe an effort could be made to select a subset of
> the Transmodel easy to read and to understand. Something like
> http://www.navitia.io/public_transport.html but better written ;)

I agree. We frequently find ourselves using the Transmodel vocabulary.
Some concepts that are essential to routing algorithms or data
integration tasks are not present in GTFS (JourneyPattern,
TimeDemandType etc.) Lack of some of these concepts is not always a
weakness in GTFS, as it simplifies the export process for agencies and
reduces the complexity of GTFS support for feed consumers. We do however
need a deterministic way to translate between the simple and rich forms.

So +1 for documenting a subset of Transmodel.
http://www.navitia.io/public_transport.html is a good starting point,
and we also need to make a formal, unambiguous mapping between GTFS and
Transmodel terms. This could be based on the previous work at:
http://www.dft.gov.uk/transmodel/schema/doc/GoogleTransit/TransmodelForGoogle-09.pdf

That document dates from 2008 and favors an XML representation of
transit data. While updating and adapting this otherwise very helpful
analysis I think we should remove that bias. The vocabulary should be
kept as separate as possible from any concrete data format.

For anyone who wants to check out the Transmodel spec:
http://www.transmodel.org/en/transmodel/maindoc/maintoc.htm

-Andrew