I've been looking at a UR at these crossroads with some interesting routing.
https://www.waze.com/editor/?env=row&lon=-1.40573&lat=50.97586&layers=1957&zoom=5

At peak times, instead of a simple 'turn right' - Waze prefers to turn left and go right round the next roundabout and then return to this junction. As this is a single lane road and there is no filter arrow at these lights this is never going to be quicker.
This issue is only at peak times as having tested in the Live Map it seems the problem only occurs on weekdays between 08:30-09:30 and 16:30-17:30.

The only reason I can think of is different segment data for turning left and turning right. I'm guessing that if in the peak periods all Waze users are queuing to turn right then this could give enough of a speed difference in the data to make the left turn seem better - and no-one has actually followed this route because it's obviously wrong once you get to the junction.

Does this seem feasible? .. and if so, should I split the segment near to the junction to better represent a single queue of traffic for all directions?