Optional offset for direction-dependent line data

[hbruch]

Is your feature request related to a problem? Please describe.
The data I'm visualizing has direction-dependent line properties like e.g.

edge_geo,avg_speed_kmph,count
"LINESTRING(9.414 54.8147,9.415 54.8146)",15.2,3
"LINESTRING(9.415 54.8146,9.414 54.8147)",22.2,5

Currently, both lines are rendered above each other, like in the screeshot below.

Describe the solution you'd like
I'd like to be able to display the each direction shifted by an offset (or just rendering half of the stroke) according to the line orientation. To accomodate left/right hand drive, a ternary option "no-shift", "shift-right", "shift-left" would be required.

Describe alternatives you've considered
Instead of shifting, just rendering the right/left half of a stroke might be easier to realize.

Additional context
Screenshot showing lines rendered on top of each other

[chrisgervang]

Not what you're looking for, but an example of a layer that has directional lines like this is https://flowmap.blue/