Rain, measured in metres, not millimetres, has not hampered progress in the Manawatu Gorge, with the road due to open early next month.
David McGonigal, the Palmerston North state highways manager for the NZTA, is confident the rebuild of the road is entering the final stages, with work progressing steadily over the past week, despite the downpour.
With torrential rain flooding the Manawatu River, which peaked at eight metres, four times it's normal level, conditions for the contractors had been challenging, Mr McGonigal said.
"Concrete work on the main bridge is finished, with crews now waiting for the curing of the concrete to take its course," he said.
"Watching concrete dry may not rival the Olympics as a spectator sport, but seeing bridge structures harden is quite rewarding for the team, as it literally means the new structure is getting stronger by the hour.
"Applying the finishing touches to the joints and the new road surface will be carried out once the concrete has hardened."
Mr McGonigal said despite the bad weather, the site had been bustling, with a big push to link the new bridge at the Woodville end to the half-bridge that already existed.
"It's quite a fiddly job, because we have to join up the old with the new and make it happen seamlessly to ensure it's structurally sound and provides an easy transition for motorists.
"We've set up temporary cantilever work platforms with staff working off ropes and harnesses or suspended from a crane, so it's pretty challenging physical work as well as being technically precise," Mr McGonigal said.
"The crew are creating made-to-measure concrete moulds on site for the remaining structures, as well as steel cages to reinforce the concrete This work is expected to take another three weeks.
"Meanwhile, drilling has continued in other areas, and the drilling rig has been suspended from a crane to enable this work to continue safely."
Excellent progress had been made on the large retaining wall which would help create room and flexibility to help move traffic through the construction site while finishing work occurred in September, Mr McGonigal said.
And improvements were also continuing on the Saddle Rd detour, which was coping with up to 7000 vehicles a day. More than $5 million has been spent on repairs there since the Manawatu Gorge closed 12 months ago.
"The recent pounding from the weather has damaged the Saddle Rd surface and we appreciate the road has seen better days after the hammering it's had from the rain, but our crews have been making the most of a few dry days to get stuck in," Mr McGonigal said.
"The Saddle is a challenging route, so motorists should drive to the conditions and be aware that the surface can be slippery."