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mtmail

Mapper since:
27. Mee 2007
Last map edit:
13. September 2025

Cofounder OpenCage. Software engineer. Geocoding. Cycling. Speaker at several SOTM conferences.

Managed to survey a whole city (10x10km) in a four month project by walking and cycling every street, paths and taking lots of photos.

2024 managed a streak of 363 mapping days (unlikely to continue at that rate).

Interested in timezones, elevation, ocean/sea, disputed border data and general tagging validation tools.

Recently cleaning up postcodes all over the world (those too long, too short, in the wrong area).

If you have spare time try https://nominatim.org/qa/ , https://osm.mathmos.net/addresses/pc-errors.html , https://osm.janmichel.eu/taginfo/newkeys.htm

Latest Diaries

Blog-Antrag New validation rule: Suspicious addr:state value

The Nominatim QA tool added a new layer “Suspicious addr:state value” If addr:state is the same addr:province. Depending on country addr:provin...

Comments 3 comments Datum 31. Juli 2025

Blog-Antrag Cleaning up US postcodes

Or zip codes as they’re called in the United States. The Nominatim geocoder has trouble parsing address queries when its OSM database table contai...

Comments 1 comment Datum 26. Mee 2019