A $50 million investment by Waka Kotahi NZTA for a top-class road surface will have big long-term benefits for the community, road users and maintenance crews.

That was the message Waka Kotahi project manager Glen Prince delivered to the Ōtaki Community Board at its June meeting.

Glen mentioned some of the roading failures that had occurred on the Mackays to Peka Peka stretch of the expressway.

“We’ve looked closely at some of those failure mechanisms down there because we certainly didn’t want to repeat that on Peka Peka to Ōtaki. As a result of some of those discussions and investigations, the agency has invested a further $50 million into what we call a structural asphalt pavement from Peka Peka to Ōtaki.

“That’s a great result for the project, the community and road users in general.”

It should mean a longer life span for the road surface and potential use of Ogpa (black top) sealing, resulting in a smoother ride and less maintenance over time.

The meeting was also told that the team could not predict when the expressway might open. It was scheduled to open about this time next year, but the Covid-19 lockdown has knocked the opening date into unknown territory.

The community board was told that it was too early to predict when the road would open, such was the effect of the lockdown.

There were two significant factors – one being the time lost when work stopped; the other that work that would have been done during the ideal autumn weather would now have to wait until spring.

Glen said Waki Kotahi had requirements around not sealing road surfaces during winter.

“There’s too much moisture in the paving and water gets under the seal and you end up with pot-holing and so on.”

That affected the new stretch of road at the southern end of the project, which would have been completed by winter this year if not for Covid-19. It would now be September-October before that road could be sealed.

“I certainly can’t give any commitments about what the opening date will look like.”

Project direct Chris Hunt told the community board progress on several sections had been good, including at the project’s biggest structure, the Ōtaki River bridge.  With an expected completion date towards the end of the year, the bridge will be used to transport a substantial amount of material across from the south side.

“It doesn’t look like there’s much there because the elevation looks the same from a distance, but there is. Ōtaki Gorge Road is about six metres above the new road alignments.”

The bridge will also be used to move asphalt from a new plant expected to be commissioned on the west side of State Highway 1. The construction team is in the process of gaining consent for the plant.

With many culverts on the project, Glenn revealed one useful snippet of information – a culvert becomes a bridge when its cross-section becomes or exceeds 2.5 metres square.

“We have a lot of culverts on this project that are technically bridges just because of the size of them.”

One recent milestone was commissioning of the settling ponds at Winstone’s Quarry. They have been handed over to Winstone’s.