Comparison of the accuracy of OpenStreetmap for Ireland with and

by Błażej Ciepłuch

Screenshot from

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

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

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?