Truckies are hoping the police checkpoint operation south of Auckland don't turn into the chaos of earlier this year, when thousands were waiting for hours.
Families, pets, animals and freight were caught for hours in February after the Auckland border suddenly closed when the super city entered alert level 3, while the rest of the country was at level 2.
Don Wilson runs a trucking company, On-Road Transport, that moves livestock.
"It was an absolute shambles," he said of February's checkpoint chaos.
"The people that made the rules didn't understand the ramifications - it was a shambles," Wilson told Newshub.
This time the alert levels are higher - levels 4 and 3 - but police are unsure whether that will make for a smoother journey.
"Until those checkpoints are set up that will really determine what that traffic flow will look like," said Supt Shanan Gray. "That's why it's difficult to say, 'will we have queues? won't we have queues?'"
Crossing the level 3/level 4 border is only allowed for essential activities. For a business that means things like freight, construction, food and utilities.
For personal travel it's vaccinations, managed isolation pickups, caring for the sick or dying, and animal welfare.
Officials are urging people to check they qualify and carry the right documentation.
Truckies say they’re ready and are hoping for priority.
"There is a nervousness in the industry that the paperwork will be accepted by those patrolling the border and that the time taken at the border will be as short as possible to allow freight to move through quickly," said Nick Leggett of the Road Transport Forum.
People can apply for exemptions online but it's too late to ask at the checkpoint.
At the Mercer checkpoint, local residents are divided by the border. On Koheroa St, come midnight houses on one side of the street remain at alert level 4 and the other becomes level 3.
That means local resident Krystal Kira resident can’t pop into the local shops - making level 3 an even bigger nuisance.
"I will have to go to Huntly that’s a 20-minute drive away, rather than just up the road," she said.