The Saddle Road will be closing for essential pavement repairs and maintenance works at various times from April 18 to May 14.
Waka Kotahi NZ Transport Agency regional transport systems manager Ross I'Anson said the work would significantly improve the condition and safety of the road.
"The narrow, steep and windy road is difficult to maintain and is a challenging environment to work on with the increased volumes of traffic since the Manawatu Gorge closure, so full closures are needed to ensure our crews have enough time to complete the work safely and to a high standard."
Subject to weather, the closures are scheduled for:
Sunday – Thursday April 18 to 22 (five night-time closures)
Night: 6pm-6am