State Highway 1 between Waiouru and Rangipo is closed this Thursday and Friday for resurfacing works.
Waka Kotahi said the closure would be in place between 9am and 6pm on Thursday and Friday to fix a number of issues that had deteriorated significantly over winter.
Road users will need to use State Highways 46, 47, 4 and 49 to detour around the western side of Mt Ruapehu via National Park.
Waikato system manager of maintenance and operations Cara Lauder said while the disruption of this closure was unfortunate, it was the only suitable option due to the locations contractors needed to work in.
"In some locations, the road is too narrow to allow vehicles to safely drive past an active worksite where crew are operating various machinery," she said.