I need to view a polyline constructed from waypoints of a gps track that has self intersections in curves; like an exit loop from a highway.

I need to visualize it in a way that shows which part is above the other in the intersection.

Option 1: Style with solid color

This does not work, as the intersection is filled without delimiting the side of the path.

enter image description here

Option 2: Style with some predefined road from QGIS:

Almost doesn't work, as each segment is surrounded by the line, not only at both sides but also in the head and tail of the segment.

enter image description here

Option 3: Enabling symbol levels:

This does not fit my need as it merges the intersections, thus preventing from seeing the precedence.

enter image description here

I've managed to do the some styling after finding this article in http://planet.qgis.org: http://nathanw.net/2012/07/22/qgis-style-tricks-using-styles-to-help-fix-kerb-line-directions/

The key for me was as easy as using a style of a marker line, with a single triangle marker, and a solid line. Then, I applied transparency so that street names are visible.

This is the result:

enter image description here

What other option could I try?

  • You have a polyline... or a multipolyline? – U2ros Nov 4 '15 at 15:27
  • It is a polyline layer. I could break the features apart but better if I don't have to. – Martin0x777 Nov 4 '15 at 15:48
  • so part of the polyline has to be overlapping itself right? the part that is an exit loop? – U2ros Nov 5 '15 at 10:38
  • Yes, question edited for clarification. – Martin0x777 Nov 5 '15 at 13:30

You are on the right track with option 2, you just need to change the cap style for the line. The pre-defined road style is actually a narrow line on top of a wide line. Change the cap style of the bottom line from round to flat. Now the bottom line doesn't stick out at the end of each segment.

enter image description here

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