MapFactor Forum

As far as I see, streets are divided by city-district boundaries (Stadtteilgrenzen), when searching. This is a confusing procedure, if you are a stranger in a city. You are completly right!

But anyhow that is much better, than MFN was a couple of years earlier. At that time you had to know the district to find a street in the first place.  ;))

Yes, I am not too deep into the admin level stuff. But for bigger cities it seems that the levels 5,6, 9 and 10 are used but not 7 and 8. Example Cologne (Köln):

Admin Level  5 = https://www.openstreetmap.org/relation/72022   = Regierungsbezirk Köln (state-district border)
Admin Level  6 = https://www.openstreetmap.org/relation/62578   = Köln                  (county border)
Admin Level  9 = https://www.openstreetmap.org/relation/2613797 = Ehrenfeld             (part of municipality 1 = Stadtbezrirk)
Admin Level 10 = https://www.openstreetmap.org/relation/2613726 = Ehrenfeld             (part of municipality 2 = Stadtteil)
Admin Level 10 = https://www.openstreetmap.org/relation/2613714 = Bickendorf            (part of municipality 2 = Stadtteil)

So Cologne as city has admin level 6 and is split into Stadtbezirke (which have their own local self-government, admin level 9). These Stadtbezirke are split into Stadtteile (admin level 10). Ehrenfeld is a Stadtbezirk but "unfortunately" it contains a Stadtteil with the same name which makes it a bit confusing. Another Stadtteil within the Stadtbezirk Ehrenfeld is Bickendorf.

For smaller cities and towns it seems that admin level 7 and 8 are used, and some cities have no admin levels above 6 (Examples in Germany: Schwerin, Crivitz, Barnin). So it seems that the map maker needs to check which kind of city it is dealing with.

From my current high level perspective I would assume that you need to check if there is an admin level 8 within admin level 6. If so, it´s most probably the city which a navigation user has in mind (example: Crivitz). This may differ from offical postal addresses though. On the other hand, if admin level 6 contains no admin level 8 but admin level 9 and/or 10, then assumingly admin level 6 defines the name of the city which the user has in mind (example: Cologne). But probably it´s a bit more complicated ;)

So from the navigation user perspective I would expect that all streets which belong to a city (AL6 resp. AL8) are not split into pieces at the first step. So if I look for "venloer" in "Köln" I want to get "Venloer Straße" and "Venloer Wall" as result. Nothing else.
When selecting "Venloer Straße" I want to be able to type a house number directly or alternatively select "ALL". In case I select a specific number which exists, the number shall be displayed as it is now but together with the admin level 10 name if it exists. So if a number exists twice because there are 2 streets of the same name in the city (often the case in Berlin), you can still see which one is the one you need. In case I select ALL instead of a specific number I want to get the street names listed split into admin level 10 pieces with the according names on it. Then I can select one of these pieces and I may be asked for a crossing or something in the next step or to show this segment on the map.

It´s a lot of text, but I hope that it makes things a bit more clear from the developers perspective even though I may be wrong or sligthly incorrect in some details or assumptions.

To be honest I don´t find any admin level 4 in Köln or Düsseldorf, and the level 6 borders are the city borders in my eyes. Without checking in detail they seem to contain everything which belongs to the city of Köln resp. Düsseldorf, thus everything which has an address in the according city.

Hamburg looks different, yes. It seems to have no official administrative suburbs like Köln and Düsseldorf (although there are parts of Hamburg which have well known names). This may be a special case of Hamburg or a mapping error. But to be honest I don´t think that the mapping is incorrect. With admin level 8 it´s the same as for little towns and cities which I mentioned in the other post, so Hamburg would still follow "my" approach.

Berlin ... let´s have a look at this town ... okay, the lower structure looks the same as in Köln and Düsseldorf (AL9 and AL10). But admin level 6 is missing as well as admin level 8, that is true. it just has admin level 4 for the federal state of Berlin (which is NRW for Köln and Düsseldorf) but no city related boundary. Don´t know whether it does not exist here or whether it wasn´t mapped or found by the overpass api.

Bremen, by the way, has a structure like Köln and Düsseldorf although it´s a state as well ...

So I think there is a kind of consistency but there may be some specialities, too, which may have either political/administrative or mapping reasons. Latter would be mapping errors if they don´t match the official reality.

Finally ... a navigation map maker seems to be required to handle some exceptions ;)

Yes, there is a node for Düsseldorf with capital=4. But this is just the node which declares Düsseldorf as capital of the state NRW. It´s not relevant for navigation. berlin should actually have capital=yes and capital=4 because it´s the "capital of itself" (4) and the capital of Germany (yes). But haven´t checked how it´s done there. Probably capital=4 does not exist or it´s a separate node.

@Nigel

There are only a three cities that are also counties

- Berlin
- Bremen
- Hamburg

Wikipedia

@chattiewoman: Yes, but Bremen consists of 2 cities in contrast to Hamburg and Berlin because it´s Bremen itself and Bremerhafen.

In Köln for example, is surroundings, every street around the city center point.

I agree with krza.
In Berlin the problem seems to be even bigger.
For example if I search a Residenzstrasse I get 9 results even though there is only one street with this name in Berlin and it is located in two districts. But even though I live in Berlin I don't know this and I only search for a house number.
It becomes totally confusing if there is more than one street with he same name.
I don't understand this with the admin levels but I also think there should be a better search algorithm to get only one time the street name for each separate road.

If I click Residenzstrasse(...) and have a joint I feel better but the results are the same ...

Okay, joke, I don´t smoke at all ... Yes, you are right, the first of the nine results with the three dots seems to cluster the eight other results down to three which is a step in the correct direction but still not reasonable. For Cologne the new map I just downloaded has not changed a lot (if at all), by the way. I tried Venloer Straße again.

So my conclusions are the following:

• The admin levels described in the Wikis are correct.
• For that reason the search approach I noted in my first post from Oct 24 should be correct.
• There may be additional checks required to find exceptions like for Bremen and Berlin but all other cities should be catched properly by the above approach based on the Wiki definitions for the German admin levels.
• The search algo should be changedas soon as possible. I don´t know whether it is driven by the map maker, thus the map data, or the application which is installed on the phone.
• In the end a street should appear only once in the list. When selecting it you should have the option to either type a house number directly or to select a street segment clustered by the combination of AL 9 and AL 10 with a slash inbetween. When selectiong that you should be able to type a house number again or to display it on the map. If you have typed a house number instead of selecting a street segment and if this house number exists, the according number (or numbers if they exist more than one time) shall be displayed in the list including the mentioned AL9/AL10 name.