2025-11-14 –, Node
With the Nominatim geocoder we've been struggling for years to make sense of boundary and place data in the UK. In this session I want to start a discussion with the UK mappers about the current state of the data, and how it can be improved.
If you are looking into dividing the world into smaller parts, administrative boundaries are a good way to start in many countries because the governmental divisions tend to align with the popular perception of areas and regions. Not so in the UK. The British Islands have a long and proud history which has shaped what locals consider as regions: shires, parishes, towns, cities. Administrative boundaries on the other hand seem to follow more bureaucratic necessities than tradition. This is a problem for geocoders which depend on the ability to identify regions and hierarchies to make places properly searchable and present results in a meaningful way.
In this talk I want to start a discussion how we could map the on-the-ground situation of boundaries and places in a way that reflects reality but still leaves the data usable for more systematic classification as geocoders would require it. I'll show what data currently exists in the UK, what would be needed to improve the data and then leave the floor to the audience to get a discussion started.
Sarah has been active in OpenStreetMap for more than a decade. She's followed many hiking paths to get them on the map and maintains waymarkedtrails.org. She works as a freelancer these days developing software for OpenStreetMap like the geocoders Nominatim and Photon.