There will be night closures on State Highway 1 in Wellington past the Victoria Tunnel during October as the road is replaced.
The work from 1 - 23 of October will be between Ruahine Street and Wellington Road.
Waka Kotahi Regional Transport services manager Mark Owen says Ruahine Street is in need of comprehensive reconstruction.
Closing the road completely will allow the work to be completed faster and more safely, he said.
As part of the project, a layer of asphalt will be added to Wellington Road up to Henry Street.
Detours will be in place for tunnel and Newtown traffic.