"Priority to alternate lanes"
I think about this at least weekly 
If on a 2 lanes road - lane B shutting
Signs saying this - 200 yards etc
Cars move to lane A
A queue develops
People go on joining lane A, some stay in lane B and go past people who have been in queue longer and bank on podging in at the end
Sometimes a lorry blocks road purposely so these people can't go past
If we had a priority to alternate lanes sign, both lanes A and B could be full - probably easing congestion behind them e.g on roundabout, traffic lights- and everyone would have their fair turn to go through narrow section
Saw it in France years ago
Can't see why it wouldn't work here?