Construction on Te Ahu a Turanga Highway across the Ruahine Ranges will begin in December.
Completion of the highway is scheduled for 2024. There will be two lanes each way for the majority of the new road including the plateau across the Ruahine Ranges.
NZTA interface manager Lonnie Dalzell says the decision to have slow vehicle lanes running continuously along the majority of the route was reached after further design work which included input from road user groups.
"We are delighted that our work with key stakeholders such as the Automobile Association, Heavy Haulage and the Road Transport Association has achieved this positive outcome."
The updated concept design for the new road replaces the preliminary concept design which would have had one lane each way with wider shoulders for about 3km on top of the Ruahine Ranges.
This means there will effectively be four main traffic lanes for the majority of the new road, providing cars with a safe and reliable journey between Ashhurst and Woodville.
The updated concept design, together with other project updates and the latest information will be presented to the public at a round of open days in the region in early December 2019.