File photo. Photo: RNZ
Waka Kotahi will begin installing two new overhead gantries with variable speed signs and extra traffic cameras on State Highways 1 and 59 north of Wellington.
Regional maintenance and operations manager Mark Owen said the signs would inform motorists of any crashes or incidents ahead.
"It also helps our teams who monitor and manage the highway network," Owen said.
"They will have a much better picture of what is happening on the highways, which will help them to respond much faster to any incidents that may occur.
"The end result is much safer highways."
About 1.6km of cabling would connect the new gantries to previously completed installations near Tawa.
Southbound lanes on SH1 between Porirua and Tawa would be closed overnight, Sunday to Thursday, from 20 August, as well as some daytime works in the area between 6am and 6pm from Monday 21 August.
"Our contractors are very good at installing this infrastructure quickly and efficiently, but it must be done safely.
"Doing the work at night when traffic volumes are lower means safer conditions for workers and less disruption for drivers," Owen said.
Owen said the signs should be running early next year.