The new Manawatū-Tararua Highway will be two lanes each way for the majority of the new road, including the plateau across the Ruahine Ranges.
NZ Transport Agency Owner Interface Manager Lonnie Dalzell said the decision to have slow vehicle lanes running continuously along most 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."
• Crash blocks both lanes of Hawke's Bay Expressway
• Driver dies after crash on Hawke's Bay Expressway
• Hawke's Bay state highways to be renamed
• Delays expected after truck crash on the Hawke's Bay Expressway
The updated concept design for the new road replaces the preliminary concept design which would have seen one lane each way with wider shoulders for about 3 kilometres on top of the Ruahine Ranges.
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.
Enabling works for the new project are expected to get under way in this summer's construction season, with project completion scheduled for 2024.