Transmission Gully: Roadworks begin tonight on SH58 at Pāuatahanui

The works are to upgrade the interchange from one lane in each direction to two. Photo / Supplied

Motorists north of the capital are asked to expect a new layout over the next six months, as work begins tonight on a major upgrade of State Highway 58.

From 9pm today

there will be stop/go management in place on SH58 at Pāuatahanui as works begin to upgrade the interchange from one lane in each direction to two.

The interchange would eventually connect to the new Transmission Gully - scheduled to open in September - with SH58 to Hutt Valley in the east and Paremata in the west.

Waka Kotahi NZTA National Maintenance and Operations manager Neil Walker said motorists should be aware of the changing layout due to construction.

Work starts on the night of Fri 12 Feb to upgrade SH58 roundabouts at Pāuatahanui. The roundabouts will eventually function as an interchange between Transmission Gully & SH58. Night works will be under STOP/GO traffic management, followed by 30km/h TSL during the day. pic.twitter.com/zDVxNWUp8r

— Waka Kotahi NZTA Wellington (@WakaKotahiWgtn) February 10, 2021

"The widening of the lanes will initially involve night works under stop-go traffic management, which will be followed by work during the day with a temporary speed limit of 30km/h."

The interchanges are being upgraded as the capital's traffic volumes are exceeding population growth expectations.

"Modelling shows traffic volumes will be much greater than originally forecast, so we are upgrading this key interchange to avoid congestion when the motorway opens," Walker said.

"Doing this work now will help avoid congestion on the ramps connecting to the Transmission Gully motorway and at the roundabouts on SH58."

When Transmission Gully opened, the transport agency expected an average of 20,000 vehicles a day to travel to and from the Hutt Valley.

The Transmission Gully motorway is due for completion in September. Photo / Mark Mitchell

Average daily traffic on SH58 between Pāuatahanui and the Hutt Valley is around 19,000, up on the 15,000 predicted in 2010.

Between Pāuatahanui and Paremata, daily traffic is predicted to drop from 19,000 to 11,000 when Transmission Gully opens.