Decreasing total length of cycleways in German cities (highway=cycleway)


For a research project I downloaded OSM data for the 50 largest cities in Germany from the overpass API, selexcted only cycleways (highway=cycleway) and summed up their length.
Then I did the same with historical data (01.07.2017).

The result was that in many cities the total length decreased instead of (what I expected) increasing.

In another attempt I filtered for different types of cycleways (DE:Bicycle/Radverkehrsanlagen kartieren - OpenStreetMap Wiki) and the sum of all types of cycleways indeed increases from 2017 to 2023.

So my question ist, can it be that the tagging in 2017 was much more generic than today and and became more and more precise until today? Or do you see other reasons?

Have you tried adding all highway=path with bicycle=designated?

So the observation is that if now less with the same search criteria, but it being illogical, the tagging on OSM in general or specifically in Germany must have been ‘evolving’. Following some looooong discussions on strassenbegleitende Radwege how things have to be mapped is a major point of contention, my impression, and the reference documents by which non-forum participating mappers challenging.

Viele straßenbegleitende Radwege sind auch als Eigenschaften der Straße erfasst:ßenbegleitende_Wege

Der Fahrradweg kann auch an der Straße gemappt sein, z.B. highway=unclassified + cycleway=track (or cycleway:both=track or cycleway:right=track or cycleway:left=track je nachdem auf welcher Seite er ist).

@whb war schneller als ich.

yes, tagging gets more precise but there are still enough cases where ways are tagged as highway=cycleway (because one can cycle there) without considering the other legal uses of the way.

@FesterShinetop war sogar noch etwas schneller und hat dies wenige Augenblicke vor uns im Eingangsbeitrag ergänzt. :smiley: