The traffic switch on the Maungatapu roundabout is expected to take place after Labour Weekend, with State Highway 29 traffic being diverted past the current route

Project director John McCarthy has revealed the temporary roadway was built over the school holidays, but saw its opening delayed by weather threats as well as a resource issue.

Video of the Welcome Bay roundabout project. Video: Supplied.

With traffic using the new pathway, equipment will begin working on the existing road.

Using a process is known as auger piling, lines of drill holes will be poured with concrete, creating two vertical walls buried in the ground from which the earth will be dug away.

'Vegetation is being cleared on the Tauranga side gully to allow for equipment as contractors prepare for the embankment construction,” says John.

'In the next couple of weeks they bring in trucks full of sand to create a drainage layer.

'They are like canvas firehoses driven into the ground and when you put weight on them, they squeeze the water out of the ground.

'Once we get the traffic switch there will be a bit of activity.”

Drainage work is also continuing on the Welcome Bay side. Large drainage pipelines are being installed in front of the former Hammond Street and down to the stormwater ponds.

The New Zealand Transport Agency will regularly release drone overflight video and time-lapse photography via their Facebook page.

The site is also able to be walked through via the footpath maintained from Hammond Street to the Kaitemako Bridge.

'It's quite unusual in some respects, to have a construction of that scale in close proximity to residential areas,” says John.

'They will make a better gradient from the footpath so they can have a more permanent footpath through there.

'There is a fair bit of interest from people walking between Hammond Street and the Kaitemako Bridge there, and people have been taking photos and watching.”

The $45 million project is expected to take three years to complete.