It's been the subject of massive local and national debate and seen miles of the M20 given over to queuing lorries.
Operation Stack, implemented by Kent Police, has proved crucial in accommodating freight delayed in the UK this summer by unprecedented industrial action and migration problems in France.
But the measures inevitably sparked a raft of myths and misunderstandings. So today, the Port of Dover has published a detailed guide for both road users and communities to help them understand the way the system works, why it's necessary and what the port has been doing to keep traffic moving now and in the future.
Tim Waggott, the port's chief executive, said: "None of us in our wildest dreams could have foreseen the double whammy of striking French workers hampering ferry routes and an unprecedented level of migrants disrupting Eurotunnel.
"There is no doubt that, for a while, the Channel link was broken. Even though the Port of Dover stayed open for business throughout, there was nothing the UK could do to resolve the situation in France.
"Operation Stack was subsequently bigger and lasted longer than ever. We were seeing phases three and four being implemented, which has never happened before and won't, I hope, happen again.
"Hauliers, motorists and the community were rightly frustrated with the disruption and this inevitably led to misunderstandings about Stack and why it's so important.
"That's why the Port of Dover has taken the step today of publishing this guidance."
Click here to download the guide.
