The Transport Agency is inviting the public to go online and check its plans for the Auckland motorway extension from Puhoi to Warkworth, dubbed the holiday highway by critics.
The agency has published the consent documents, including a map of the proposed route on its website.
It runs to the west of the existing state highway, eliminating bends, bypassing Warkworth itself and emerging just north of the town.
Northland's Regional Transport Committee chair John Bain says the $100 million project will cut costs and travel time for Northland exporters and travellers.
Critics have labelled the project the holiday highway, saying it will benefit mainly Auckland commuters and bach owners.
But Mr Bain says the Transport Agency is spending $150,000 planning the route north from Wellsford and he is confident the highway will eventually reach Whangarei.
The agency documents say the project will lead to residential, industrial and commercial growth in Warkworth.
Warkworth is identified as a satellite town in the Auckland Plan and its population is expected to grow from 3,000 to 20,000 by the year 2050.
The highway construction is expected to begin in 2016 and will take five years.