Rebuilding of the road through the Manawatu Gorge is continuing despite the recent heavy rain.
The Transport Agency says crews are close to laying the new surface and it is confident motorists will be using the stretch of road early next month.
The temporary road through the gorge has been closed because rising river levels have caused significant erosion, and it will remain shut until further notice.
Agency spokesperson David McGonigal says the new road will be opened in two phases, starting in a few weeks with one lane at first.
He says both lanes will be finished by the end of September.