In March this year a section of State Highway 1 at Milburn, just north of Milton, was resurfaced with a fabric seal.
But it has quickly deteriorated and the NZ Transport Agency has been forced to reduce speed on the patch of road.
The section is losing chip and the fabric layer has been exposed, increasing the risk to road users and vehicles.
The NZTA has responded in the short term with various repair methods, but those tried so far have not stopped the deterioration.
The seasonal weather and recent cold snaps have made the process difficult to manage.
The No 1 priority was road safety, so until the surface could be fully repaired, speed restrictions were in place and signs warning of loose chip had been installed,
NZTA senior network manager Coastal Otago Chris Harris said.
Some progress was made last week.
"We completed further works earlier [last] week when we had fine weather, but ... we are limited in what we can do in the middle of winter," he said.
"Part of the site appears to have been successfully ‘locked down’ with an additional seal coat, but we still have a problem area immediately north of Calder Stewart with chip loss resulting in a smooth surface with minimal texture.
"A pavement repair [dig-out, subsoil and granular reinstatement] was completed earlier this week and that is holding well."
The site was inspected on Friday morning and it was decided it was safe enough to increase the speed limit on sections at the ends of the section of road from 50kmh to 70kmh.
"The central section needs to remain at 50kmh [as] the seal was unsuccessful. We will continue to monitor the site and sweep where necessary to keep it safe for road users, with a further inspection planned for late next week to reassess the condition of the surfacing and the temporary speed limits.
"Safety is our No 1 priority and we appreciate the care that motorists are taking while driving through the site. People are slowing to 50kmh, which is pleasing to see. We thank all road users for their patience."
