|The German road reference key is a unique sequence of 17 digits identifying streets.|
|Used on these elements|
|Status: in use|
|Tools for this tag|
A five-digit road key ("Straßenschlüssel") is used in conjunction with a twelve-digit region key ("Regionalschlüssel", "Gemeindeschlüssel") to form a unique reference key for each road in Germany.
In OpenStreetMap, this allows to validate the completeness and correctness of streets. Further, it allows data consumers to identify streets without considering further administrative data.
The road reference key's composition is as follows:
- the first two digits denote the Bundesland (state)
- the 3rd digit stands for the Regierungsbezirk (administrative district)
- the 4th and 5th digits identify Kreisfreie Städte (urban districts/independent cities) and Landkreise (rural districts)
- the 6th to 9th digits define Gemeindeverbände (municipal associations)
- the 10th to 12th digit is for Gemeinden (municipalities)
- the 13th to 17th digit is for the street's reference key
An example is 14 5 21 5115 430 00520, which references the Albertschachtstraße in Niederwürschnitz
- 14 Saxony
- 5 Chemnitz region
- 21 Erzgebirgskreis district
- 5115 Lugau town
- 430 Niederwürschnitz municipality
- 00520 Albertschachtstraße
In states without administrative districts, the 3rd digit is 0. Large cities can have a single municipality code, even if they have subordinate administrative units. E.g. Berlin has the municipality key 1100000000, consistently applied in all city districts.
The key de:strassenschluessel=* is set to the street without spaces as value. The key would also mark the street as official, since there is only one key for it. It also makes it easier to find all parts of a street and to avoid confusion in case of rare duplicate street names within a city. Since only a few streets are currently provided with the key, some groups recommend marking known unofficial streets with the de:strassenschluessel_exists=no tag.