evaluate DCAT (Data Catalog Vocabulary)

[transitland]

evaluate DCAT (Data Catalog Vocabulary)

[pietercolpaert]

• unclear how to best implement in JSON (vs. heavy RDF/XML)

Using JSON-LD. It’s quite straightforward.

• would this enable associations between GTFS and GTFS Realtime feeds, MDS and GBFS feeds, etc.?

At least you would be able to filter an opendata-portal on the specification the specific dcat:Distributions comply to. An example of how we described transport datasets in DCAT during a project can be found in this whitepaper by @dachafra: https://oasis.team/storage/app/media/O1.2%20TransportDCAT-AP%20and%20Controlled%20Vocs.pdf

An example of this in production to describe GTFS feeds in Belgium: https://gtfs.irail.be/metadata

Also related: http://vocab.gtfs.org/terms#Feed from https://github.com/OpenTransport/linked-gtfs

I created that, but never actually used it in practise for discovery. Open to suggestions on how to extend that though!

[drewda]

Potential advantages:

• if a platform like Transitland emits DCAT, users could consume some or all of this and federate in on their own open data portal, like CKAN: https://ckan.org/portfolio/federate/
• if a platform like Transitland consumes DCAT, it could more easily fetch feeds hosted on CKAN, etc.

Potential downsides:

• unclear how to best implement in JSON (vs. heavy RDF/XML)
• would this enable associations between GTFS and GTFS Realtime feeds, MDS and GBFS feeds, etc.?

[drewda]

Relevant example: Navitia shares their feed catalog on https://navitia.opendatasoft.com/ (which emits RDF)

[LeoFrachet]

When I'll have the time I'll draft a JSON-LD version of DCAT. It should be pretty straightforward, I just have to find the time to do it. Many players are already using such spec, but without clear public specification.

[drewda]

@LeoFrachet sounds good. How about creating a sample using @trilliumtransit's list of public feeds? (As you know, they publish very clean data, it's already in Transitland Feed Registry, and their staff are involved in Transitland data curation -- so it could be an easy example to begin with.)

[drewda]

Also related: http://vocab.gtfs.org/terms#Feed from https://github.com/OpenTransport/linked-gtfs

[drewda]

We're having good luck with DMFR as basic JSON files, along with a JSON Schema. So will close this issue.

In the future, it could be interesting to try also transforming the contents of a DMFR file into DACT, for use by other types of consumers.