What Impact has the OSM License Change in Germany on the Street Network Length? – 1st Attempt –
by Pascal Neis - Published: January 15th, 2012
The OpenStreetMap project will possibly finalize its license change on April 1st 2012. There are certain concerns in the community about possible data losses and to keep them as little as possible, several remapping activities have been started. A really nice overview of “Remapping principles” and “Tools to help you” can be found here.
Frederik’s OSMInspector (OSMI) and Simon’s CLEANMAP are two very handy remapping tools. Both display data that will likely be removed after April 1st due to the fact that this data was collected by contributors that did not accept the license change. In Germany you will find several areas that are affected by these changes and might even leave some new blank spots in the map. But what impact do these changes have on the total length in kilometers per street category in Germany?
You can find several files regarding the OSMI license change view at a Geofabrik server here. Based on the “ways” shape file that you can find there it is possible to calculate the total length of the ways, which will likely be removed with the license change. However, sadly the “ways” shape file does not include any “highway” attribute, but luckily it includes the OSM IDs. This means that to be able to do a Germany street network analysis you will have to download the Geofabrik Germany OSM *.pbf file. By applying a short script you can get all OSM way IDs in Germany with their highway=* key/value pair. Combining these with the “ways” shapefile allows us to calculate the total lengths of each highway type for “Germany” (based on the Geofabrik extract!).
The following image shows the results of a first attempt to visualize the values per street category. Overall this means that based on the current (January 15th 2012) license agreement/disagreement situation about 5.4% (94000 km) of the current street network in Germany will be removed after the license change in April. The relative difference for each highway type lies between 3-8%. Last week (Jan. 7th, 2012) the total amount in Germany was 5.9% and 103000 km.
The OSMI License Change view contains not only the data that will potentially be removed in the future but also some information on two additional feature-types: Features, which have been modified and features which have been modified in some minor way by a contributor that declines the license change. In the first case we have a total street network length of about 58000 km that is affected and in the second case about 17000 km. Remember, these numbers only reflect the situation in Germany! You can find more information about the different feature types here: “Understanding the Colour Scheme“.
Notice: This was a short hack done last night, but I think those numbers look realistic. Can anyone confirm this for Germany? I am very curious how and if these numbers will decrease in the next few weeks. What do you guys think?
thx @ maɪˈæmɪ Dennis