Comparison of the accuracy of OpenStreetmap for Ireland with Google maps and Bing Maps
by Błażej Ciepłuch
Screenshot from Marble
Éire Place of our Research
StratAG project http://www.stratag.ie/
- StratAG = 5-year multi-disciplinary research project in geotechnologies
- One challenge for the next 3 yearsWff is the measurement of Spatial Data Quality
- Our plan is to build a tool set for the semi-automatic measurement of spatial data quality
- We present here a preliminary study where we manually compare quality of OpenStreetMap Vs Bing maps Vs Google maps
Drogheda
Dublin
Ennis Maynooth
Five Different Irish town was chosen
Waterford Ennis As example of medium size town in west Ireland
Waterford Big city in south part of Ireland
Maynooth small town on east
Drogheda medium town on north east
Dublin Major city in Ireland
4 km2
On every of this town we overlay boxes with middle in approximated city centre
KML file
Open Layers PostGIS database GDAL
How we prepare data to overlay
All the OSM roads inside box was taken in form of KML files and overlay on map
Because we haven't Bing/Google database to our disposition We made a checking of geometries by graphical overlay OSM
Data on proprietary maps OSM red data overlaying on Google maps in Open Layers Example in Drogheda
OSM red data overlaying on Bing maps in Open Layers Example in Drogheda
OSM red data overlaying on Yahoo maps in Open Layers Example in Drogheda
Visual inspection of roads completeness and accuracy starts.
Bing Google OSM
Primary 100% 100% 100% roads Regional 99% 98% 97% roads Housing 97% 100% 100% Estates
Roundabouts Bing Google OSM Primary 6 6 6 roads Regional 4 8 10 roads
Ennis
Bing Google OSM
Ennis
Bing Google OSM
Motorway 100% 100% 100%
National 100% 100% 100% roads Regional 97% 96% 99% roads Housing 97% 100% 52% Estates
Roundabouts Bing Google OSM Regional 6 4 6 roads Housing 5 7 2 Estates
Drogheda
Bing Google
Drogheda
Bing Google OSM
Motorway 100% 100% 100%
National 100% 100% 100% roads Regional 99% 100% 100% roads Housing 82% 89% 100% Estates
Roundabouts
Bing Google OSM Regional 2 2 3 roads
Maynooth
Maynooth
Bing Google OSM
Motorway 100% 100% 100%
Regional 96% 100% 100% roads Housing 85% 100% 99% Estates
Roundabouts
Bing Google OSM Regional 11 13 14 roads Housing 4 5 8 Estates
Waterford
Google Bing
Waterford
Bing Google OSM
Motorway 100% 100% 100%
National 99% 97% 100% Roads Regional 92% 96% 95% roads Housing 100% 100% 98% Estates
Dublin
Bing Google
Dublin
Bing Google OSM
Ennis 98% 99% 99%
Drogheda 99% 99% 87%
Maynooth 95% 97% 100%
Waterford 93% 100% 99%
Dublin 97% 98% 98%
Final Results
- Motorways are always CORRECTLY shaped in all systems 100%
- National Roads are also REPRESENTED ACCURATELY in all systems but sometimes data IS a little outdated especially in the proprietary systems
- When the city is well mapped like Waterford or Dublin we have nearly all regional roads and estates PRESENT in Openstreetmap. In Drogheda THERE are still big gaps in the coverage of roads.
Conclusions
Automatic scanning of Ireland to check how many kilometres of railway lines is inside box
Thank you
Questions?