OSM Data Quality by Country: Where It's Best and Where It's Lacking
OpenStreetMap is the world's largest open map with 10+ million contributors. But data quality is unevenly distributed: in some countries, OSM is more detailed than Google Maps; in others, it contains only major roads. Let's examine what quality depends on and where data is most complete.
How to Measure OSM Data Quality
Geodata quality is assessed using five primary metrics.
1. Completeness
What proportion of real-world objects are mapped. For example, if a city has 50,000 buildings and OSM has 45,000, building completeness is 90%.
2. Positional Accuracy
How precisely objects are located on the map. On average, OSM objects in Europe have 1-3 meter accuracy (thanks to GPS tracks and satellite imagery). In developing countries — 5-20 meters.
3. Attribute Completeness
Not just "there's a road here," but "this is the M1 motorway, 4 lanes, max speed 110 km/h, surface — asphalt." Attributes are critical for routing and analysis.
4. Temporal Accuracy
How quickly real-world changes are reflected on the map. A new shopping center — how many days/months until it appears in OSM?
5. Logical Consistency
Are there contradictions: a building inside a river, a road disconnected from the network, duplicate objects?
Leaders: Countries with the Best Data
Germany
Germany is the OSM gold standard. Nearly 100% of buildings are digitized, the road network is more complete than commercial providers. Reasons:
- Active community. One of the largest OSM communities worldwide
- Commercial data restrictions. Strict data laws created demand for open alternatives
- Cadastral data imports. Many federal states permitted government data imports
Metrics: building completeness ~98%, roads ~99%, POI ~85%.
France
France benefits from mass import of government registry data (cadastre.gouv.fr). Buildings with precise outlines, addresses via BAN (Base Adresse Nationale).
Netherlands
BAG (Basisregistratie Adressen en Gebouwen) import provided 100% building coverage with precise outlines and addresses.
Japan
Unique case: the main contribution comes from automated imports from Yahoo! Japan and government datasets. Roads and buildings in cities are mapped almost completely.
Czech Republic, Austria, Switzerland
High quality thanks to active communities and partial government data imports.
Mid-Level
Russia
Major cities (Moscow, St. Petersburg, Kazan, Novosibirsk) have good coverage — buildings, roads, POI. However:
- Small cities and towns — often only main roads
- Courtyard driveways and pedestrian paths — incomplete
- Russian-language names — good; Latin transliteration — fragmented
Building completeness: major cities ~70-85%, small towns ~20-40%.
United States
A paradox: the country with the most technology companies, but uneven OSM coverage. The road network was imported from TIGER/Line (Census Bureau) — complete but with artifacts. Buildings — fragmented, depends on local community.
- New York, San Francisco: excellent
- Midwest, rural areas: roads only
Brazil, India, Indonesia
Large countries with active but insufficiently large communities for full coverage. Major cities — good, rural areas — minimal.
Lagging Regions
Central Africa
The least covered region. Many settlements are completely absent. Primary data comes from humanitarian projects (HOT — Humanitarian OpenStreetMap Team), which map territories before and during crises.
Central Asia
Uzbekistan, Turkmenistan, Tajikistan — minimal coverage. Main roads exist, but buildings, POI, and details are practically absent.
North Korea
One of the emptiest regions in OSM. Mapping is done exclusively from satellite imagery by external enthusiasts.
Factors Affecting Quality
1. Community Size and Activity
The primary factor. Germany (300K+ contributors) vs Chad (<1000 contributors). The correlation between active mappers and data quality is nearly linear.
2. Government Data Imports
Countries that allowed government geodata imports into OSM see dramatic quality jumps:
- Netherlands: BAG (buildings + addresses) → 100% coverage
- France: cadastre (buildings) → 95%+ coverage
- Canada: StatCan (boundaries) + CanVec (terrain, water features)
3. Satellite Imagery Availability
Bing Maps, Mapbox, ESRI provide imagery for tracing in OSM editors. Areas with cloud cover (tropics) or without fresh imagery are harder to map.
4. HOT Humanitarian Missions
The Humanitarian OpenStreetMap Team organizes mapping marathons before and after natural disasters. This is the primary data source for many African countries.
5. Commercial Partnerships
Facebook/Meta, Apple, Microsoft use OSM and contribute improvements back (roads from AI image analysis, buildings from satellite data).
Comparison Table
| Country/Region | Roads | Buildings | POI | Addresses | Overall |
|---|---|---|---|---|---|
| Germany | 99% | 98% | 85% | 90% | A+ |
| Netherlands | 99% | 100% | 80% | 95% | A+ |
| France | 98% | 95% | 75% | 85% | A |
| Japan | 97% | 90% | 70% | 60% | A- |
| Russia (cities) | 90% | 75% | 60% | 40% | B+ |
| USA (cities) | 95% | 50% | 55% | 35% | B |
| Brazil (cities) | 85% | 40% | 40% | 20% | B- |
| India (cities) | 80% | 30% | 35% | 15% | C+ |
| Nigeria (cities) | 60% | 20% | 15% | 5% | C- |
| Chad / CAR | 30% | 5% | 3% | <1% | D |
Percentages are approximate estimates for urban areas.
How to Check Quality Before Export
Before using OSM data for a serious project, evaluate quality in the specific area:
-
Visual inspection. Open the area on osm.org and compare with satellite imagery. If OSM buildings cover less than 50% of what's visible in imagery — data is incomplete.
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Ohsome API. The ohsome.org service provides OSM change statistics: object counts, last edit dates, mapper activity.
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OSM Inspector. A Geofabrik tool for finding errors: invalid geometry, unclosed polygons, missing tags.
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osm2cdr.ru statistics. City dashboards show object counts by category — if POI objects for a 500K-population city number less than 1000, data is incomplete.
How to Improve Data
If data in your region is incomplete, you can contribute:
- iD Editor (id.openstreetmap.org) — browser-based editor, suitable for beginners
- JOSM — desktop editor for advanced users
- StreetComplete — mobile app (Android), turns mapping into a quest
- MapRoulette — micro-tasks for fixing errors
Every correction you make is available to all OSM users worldwide — including when exporting via osm2cdr.ru.
OpenStreetMap data quality is uneven but constantly improving. For Europe and developed Asian countries, OSM is a reliable source. For developing regions, it's valuable but requires verification.