To be precise, Keith and I were only talking about the 'no-deal' case. As to the date and time, it is earlier in this very thread. I said 'below', which is a bit confusing because it depends how you read the threads, but 'earlier' is clear enough. And it was based on fairly measurable things, like whether the motorways are being used as lorry parks three months after March 29th 2019.
As a measure of the effects of Brexit, it needs to be made clear that the above is (presumably) talking about 'semi-permanent' use of the motorways as lorry parks. Let it be clear whether it is because of Brexit, rather than because of strikes in France