Cluster Points alongside lines with a limit

Question

In QGIS I have a street layer (lines) and a house layer (points) with a start point (red rectangle):

I want to cluster the points alongside the line layer in groups of 20 or 10 points (I prefer 20). The result should look like that:

Each coloured line represents a different cluster. The result was made manually and took a long time, is there any possibility to cluster the points automatically? I only prefer groups of 20 and 10 adresses per line, in some cases I have to use a bit less or more.

Answer 1

1. Project the points (houses) to the line (streets). Use the following expression or see here for details: closest_point (overlay_nearest ('street',$geometry)[0],$geometry). Name the resulting point layer as addresses.

   Red points created based on your blue points:

2. Create the shortest path from your start point to each address along the street layer with network tools. Run Menu Processing > Toolbox > Shortest path (point to layer).

   

3. In the resulting line layer (a line for each address/house), calculate how many addresses/houses are on this line. Use this expression to create a new attribute field called no_of_houses: array_length(overlay_nearest ('addresses',$id,limit:=-1,max_distance:=0.01))

4. Delete features with a value for no_of_houses smaller than 20. Keep the ones with no_of_houses = 20.

5. Lines with value larger than 20 have to be split up. Select features with no_of_houses=20 and create the end point of these lines with Geoemtry by expression: end_point ($geometry). Name the resulting layer end_points.

6. Use these end points to split the remaining line layers with no_of_houses < 20 and keep only that part of the line after the end points. Use this expression with Geoemtry by Expression:

   line_substring (
    $geometry,
    line_locate_point (
        $geometry,
        overlay_nearest('addresses',$geometry)[0]),
    length($geometry)
    )
   

7. Repeat step 3 to 7 until no more no_of_houses values are larger than 20.

8. Don't forget to delete remaining superfluous lines, resulting in step 6. Use e.g. Delete duplicate geometries.