Part of Mackays to Peka Peka Expressway undergoing repairs after six months

Patching up part of the Mackays to Peka Peka Expressway, north of the Makarini footbridge. Photo / David Haxton

A seven-month-old road has been partly closed for repairs.

The NZ Transport Agency's ongoing inspection of the Mackays to Peka Peka Expressway has shown "minor fatigue of the surface" over an area of 3.2km (about 2.4km south bound and 0.8km north bound) in the vicinity of Kapiti Rd.

The 18km four-lane expressway was opened to traffic on February 24 this year, four months ahead of schedule.

"It appears that the issue has been caused by water penetrating the membrane seal that was applied to the pavement prior to the surfacing (OGPA) being laid," the agency's Wellington transport systems manager, Mark Owen, said.

"This has subsequently loosened small particles in the top of the pavement which causes the discolouration and texture changes.

"We are satisfied that the current issues do not present any safety risks.

"Weather permitting repairs of the affected surface have been under way in the last two weeks and will continue this week.

"It's expected that any additional works that might be required will be completed during the summer re-sealing season (late 2017/early 2018).

"An independent review has been commissioned by the M2PP alliance, which the Transport Agency will contribute to, to establish how the issue occurred."

The expressway is a finalist in two different categories of the Civil Contractors New Zealand Hirepool Construction Excellence Awards - for projects valued between $20 million and $100 million while the overall project is in the category for projects valued more than $100 million.