seriously, this is my particular bugbear bit of road near me….
https://www.google.co.uk/maps/@51.2675465,-0.5831388,3a,75y,299.9h,92.34t/data=!3m6!1e1!3m4!1s2GwvP6TfWvjLje_B4sRk1g!2e0!7i13312!8i6656
the road curves just after the railway bridge so you can’t see if anything’s coming. So i take primary coming up to it to dissuade cars from overtaking me, but it’s a NSL road so they are often doing 50-odd mph and think they can get past before the bridge – but where it’s a nice downhill gradient I’m going faster than they seem to realise too.
I reckon 20% of the times I go through there the car behind misjudges and has to brake hard to pull back in behind me when they realise they can’t get through before the bridge – usually with accompanying horn
And maybe 1/4 of those times they just overtake anyway.
It’s almost identical the other way round too.
I have no idea why it isn’t no overtaking / double white lines (not that that matters where bikes are concerned in the eyes of most drivers, but it might make them think)