The closures will start on December 4 — Westland Anniversary Day — and run through to December 15, each day from 10am to 6pm.
Waka Kotahi system manager Mark Pinner said West Coast motorists would need to be at Otira by 10am if they were heading east on State Highway 73, and back at Arthur’s Pass after 6pm to get home.
The route would be open throughout the weekend in the middle, December 9-10.
The closure has been met with disbelief from the tourism sector.
Greymouth iSITE and Hotel Lake Brunner owner Phillip Barnett said he had a fishing competition over Westland Anniversary weekend.
"It seems beyond belief," he said yesterday.
He understood the councils had pressured the transport agency to change its plans.
Lake Moeraki and Arthur’s Pass tourist lodges owner Gerry McSweeney said the lodges would be full with international tourists throughout the closure.
The closure was "absolutely outrageous ... [and a] destruction of the tourism industry at peak".
He understood the agency had consulted with the trucking industry, which said it could work at night — "essentially destroying the tourism industry which uses Arthur’s Pass".
Tourists would not travel in the dark or early morning, he said.
"It’s a real test for [National Party West Coast MP] Maureen Pugh and the new Government — she [Pugh] lives on Highway 73."
Greymouth Mayor Tania Gibson said the work had been pencilled in for January, so early December, when schools were still in, was better.
"It has to be done.
"May would have been preferable but it needs to be done properly once."
The agency said Arthur’s Pass and Otira townships would be accessible at all times from each side of the Main Divide, and emergency services would be escorted through as required.
Waka Kotahi system manager Mark Pinner said the agency knew the closure would be unwelcome for many regular road-users, businesses along the route and visitors to the Coast.
But the fortnight before the Christmas holidays had the least impact overall, compared with later options, and followed extensive engagement with travel, hospitality and freight operators.
"Our aim is to ensure that the highway remains safe and fit for purpose for many years to come," Mr Pinner said.
"We want to reduce the potential for more frequent short-term delays in the future due to failures in the road surface."
