Osm Hack Weekend February 2025

Last weekend I once more attended the biannual OSM Hack Weekend hosted by Geofabrik in Karlsruhe, Germany, discussing and working on things related to Itinerary, Transitous and emergency and weather alerts.

KDE Itinerary

With an growing number of Itinerary users among the attendees the first order of business for me was fixing a bunch of issues that got reported:

• Fixed importing of Finnish VR mobile PDF tickets for sleeper trains.
• Added support for SBB PDF itineraries, as the barcode-based fallback on those would provide way too little detail.
• Fixed location identifier-based journey queries on the Swiss OpenJourneyPlanner API. Those require at least also a dummy location name field to work, and this enables retrieving online information for train trips in Switzerland.
• Investigated a missing dependency in Debian packaging making Itinerary not start correctly on a Mobian system.

Together with the maintainer of Nominatim we also reworked importing OSM elements into Itinerary. This was using OSM API directly so far, which works fine if the corresponding element is fully tagged. However, If there’s no complete address information we can get much better results by querying Nominatim instead.

Open Transport and Transitous

On Sunday I was asked to do a spontaneous presentation about Transitous, which resulted in a number of interesting discussions.

• GTFS editor tooling for community-maintained schedules for small (community-run) services that don’t provide official GTFS data. Transitous would be the obvious service to consume such data, but to my knowledge nothing like this exist yet.
• Covering flights in Transitous and the implications of that for the routing. Challenges here are availability of the data and considering realistic transfer times during routing.
• Update frequency of the OSM data used by Transitous, as well as OSM indoor routing and level tagging.
• Interest in reusing the pre-processed Transitous dataset for local/special purpose instances. That’s already being done by the MOTIS team, but we might lack documentation for this.

There also was a discussion about ideas for a dedicated Open Transport conference. Interest in this keeps increasing, and attaching this to existing conferences like FOSDEM or FOSSGIS Konferenz keeps hitting limits as those are already operating beyond capacity.

Good to see more efforts towards connecting the OSM and the Open Transport communities even better. There is a lot of overlap already, but at the same time there’s also some parallel work going on.

Emergency and weather alerts

My main objective for this weekend was getting to a solid plan on how we could implement an alert map view for our public alert server. The main purpose for this is monitoring and diagnostics, as at usually over 1000 active alerts all over the world it’s hard to spot questionable things by looking at a database table.

Prior to the hack weekend I had built a primitive prototype using Leaflet and a GeoJSON file containing all alerts which the server regenerated once a minute. Not particularly efficient, but fairly simple.

Let’s just say the people knowing how to do things like this were not impressed by my creation. I got pointers on how to do this properly using dynamically generated vector tiles and MapLibre.

This turned out to be even easier than my naive prototype, thanks to pg_tileserv magically producing vector tiles from the PostGIS database we already have for the alerts.

It also looks like this is significantly more efficient, to the point this might also hold up as public API rather than just for (internal) diagnostics.

You can help!

Hack weekends how this is called in the OSM community or sprints as this is known in the KDE community are immensely valuable and productive. There’s a great deal of knowledge transfer happening, and they are a big motivational boost.

However, physical meetings incur costs, and that’s where your donations help! KDE e.V. and local OSM chapters like the FOSSGIS e.V. support these activities.