Getting count of overlapping portion of different line features within one shapefile using QGIS?

Question

I have a line shapefile that has overlapping on certain portion of the line features. I need to know the count of where these overlapping occurs and if there is no overlap to keep it as Null or 0 as it still a count of 1 line that passes through the route. I have a point shapefile of where these lines start and end.

Eg. A line runs from 1>2 another lines run from 1>3 and one from 1>5. A line runs from 2>3 and another line from 3>4.
In the portion of the red box I know there should be overlapping as the lines that feed 1>2, 1>3 and 1>5 have the same route (geographic location as well). Portions 2>3 and 3>4 of the line has no overlap.

I am trying to figure out a workflow and I am using QGIS 2.18. Any ideas?

Answer 1

You can (1) break these lines into segments, (2) count overlapping segments, and (3) keep only one feature at each location (while removing others) just for labeling.

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(1) Explode lines (Processing Toolbox | QGIS geoalgorithms | Vector geometry tools) to break polylines into segments.

(2) Open the attribute table of the above exploded layer. Start the Field Calculator and create a new integer field with an expression count("id", group_by:=geom_to_wkt($geometry)) ... if you have id field.

(3) Remove duplicated segments by Delete duplicate geometries (Processing Toolbox | QGIS geoalgorithms | Vector general tools). This will ensure not to show multiple labels at each segment.