OpenStreetMap data

Extracting an OpenStreetMap data dump for a specific region

1. Download a dump for a larger region from here: http://download.geofabrik.de
2. Search for the OSM id of the region that you want to extract here: http://ra.osmsurround.org/
3. Download the poly file given the id here: http://osm102.openstreetmap.fr/~jocelyn/polygons/index.py
4. Install osmosis (sudo apt-get install osmosis)
5. Read the larger region dump, bound by poly file, write the region dump: osmosis --read-xml file=finland.osm.bz2 --bounding-polygon file=helsingin_seutukunta.poly --write-xml file=helsingin_seutukunta.osm.bz2