I am using QGIS 3.10.3. I try to symbolize routes in both direction (CL1 and CR1). Using the rule based symbology and created 4 sections according to the values. I filtered the data using <= and >= symbols. enter image description here Example: Subsection <= 0.000000 AND Subsection >= 39.999999

Then, I changed the offset to -3 for the opposite road (CL1). For some reasons, some lines are missing in the network. I have a feeling the offset must be the reason but not 100 percent sure. enter image description here

  • offset shouldn't be a problem, did you check that offset (and whole symbology) unit are all mm ?
    – J.R
    Commented Jul 5, 2022 at 9:58
  • 1
    Sorry it's QGIS 3.10.3.A Coruna
    – GIS Noh
    Commented Jul 5, 2022 at 9:59
  • yes they are in millimeters
    – GIS Noh
    Commented Jul 5, 2022 at 10:01
  • Try reversing the line direction of the outlier
    – Hans Erren
    Commented Jul 5, 2022 at 10:57
  • Thanks, I created a new shapefile for the missing line and reversed the offset to 3. It seems to work as the line is now in the network. I suppose I will have to make a new shapefile with all the missing ones and do the same thing.
    – GIS Noh
    Commented Jul 5, 2022 at 11:17

1 Answer 1


The offset left or right is dependent on line direction. You can reverse the direction of lines by selecting them and using the QGIS tool Processing > Toolbox > Vector geometry > Reverse line direction

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