OpenStreetMap (OSM)¶

OpenStreetMap is a free, editable, crowdsourced map of the world. For most countries, it's the best free source for roads, points of interest, buildings, and amenities.

What's in OSM¶

Everything is one of three geometry types: node (point), way (line/polygon), or relation (multi-polygon, route).

Each feature has tags — key=value pairs:

highway=residential
name=Main Street
maxspeed=25 mph

Common tag categories:

Reference: https://wiki.openstreetmap.org/wiki/Map_features

How to download¶

1. Geofabrik (country / region extracts) — start here¶

https://download.geofabrik.de/

• Pre-built regional extracts (e.g., "north-america/us/texas").
• Formats: .osm.pbf (compact), .shp.zip (split by feature class).
• Daily updates.
• The shapefile zip is the easiest entry point — drop it into ArcGIS Pro.

2. Overpass Turbo (custom query)¶

https://overpass-turbo.eu/

A web tool that lets you query specific tags in a bounding box. Great for "all bus stops in Austin" or "all schools in San Diego."

Example query — all hospitals in a bbox:

[out:json][timeout:25];
(
  node["amenity"="hospital"]({{bbox}});
  way["amenity"="hospital"]({{bbox}});
  relation["amenity"="hospital"]({{bbox}});
);
out body;
>;
out skel qt;

Click "Export" → "GeoJSON" or "KML."

3. JOSM / OSMnx / pyrosm¶

For programmatic / large workflows:

• OSMnx (Python) — quick urban network analysis.
• pyrosm — efficient PBF parser to GeoDataFrame.
• JOSM — heavyweight desktop OSM editor.

OSMnx mini-example:

import osmnx as ox
g = ox.graph_from_place("Austin, Texas, USA", network_type="drive")
ox.plot_graph(g)

4. Hosted OSM tile services¶

• Mapbox, Maptiler, Stadia Maps — basemap tiles.
• Esri "OpenStreetMap" basemap — built into ArcGIS Pro.

In ArcGIS Pro¶

Loading OSM data¶

1. Download the regional shapefile zip from Geofabrik.
2. Unzip — you'll get gis_osm_roads_free_1.shp, gis_osm_pois_free_1.shp, etc.
3. Drag into your ArcGIS Pro map.
4. Reproject if your project is in another CRS (OSM ships in WGS84).

Filtering (Select by Attributes)¶

-- Only major roads
fclass IN ('motorway','trunk','primary','secondary')

-- Only schools and hospitals
fclass IN ('school','hospital')

Editor toolbox¶

Esri also publishes an OSM editor for editing OSM directly from ArcGIS. Most analysts don't need this.

QA notes¶

Validating coverage¶

A quick way to gauge OSM completeness for your area:

1. Open https://www.openstreetmap.org and zoom in.
2. Compare detail with imagery basemap or local knowledge.
3. Check the "history" panel — when was the area last edited?

Licensing¶

OSM data is licensed under the Open Database License (ODbL):

• ✅ Free to use, including commercially.
• ✅ Free to remix and redistribute.
• ❗ You must attribute OSM contributors.
• ❗ Derivatives that release data must be ODbL.

Recommended attribution: "© OpenStreetMap contributors" on every published map.

Common OSM data products you'll use¶

OSM vs other sources¶

→ Next: Living Atlas.