I have a group of lines (bus lines, some of them coincident in some sections) that I want to convert into a single polyline (or polygone) to style it as a single entity.
I know how to put them into one single shapefile, using "Vector > Data Management Tools>Merge Shapefiles to one".
The problem I have is that I want to show the whole shapefile with a single style, but QGIS keep working with all the lines separately, even if they are in a single Shapefile. Here an example of this:
The first thing I tried is to use the Dissolve Geoprocessing tool from Vector menu, but I get the same result as merging shapefiles.
I've tried to convert all the lines into polygones, through "Geometry Tools > Lines to polygones", but this is what i get:
I've also tried using the Polygonize tool from Processing plugin, and this is the result:
I don't know how to convert all the lines into a single polygon that i can style to obtain something similar to the first image but with no overlaping (just the outer segments in black, with no crossing of black lines).
The only solution I can imagine would be very time consuming and not very elegant (and may not work) is to create buffers for all the lines and then dissolve all this buffers. That may create a single polygon that can be styled as I want. The problem is that I have more than 70 lines.
Any solution / approach?
(QGIS 2.8.6 on Windows 7)