Northland council leaders are urging the government not to shelve plans for a four-lane highway from Whangarei to Warkworth.
Work has begun to extend the motorway from Puhoi to Warkworth and the National government said during the election campaign it would extend it first to Wellsford, then all the way to Whangarei.
Prime Minister Jacinda Ardern has appeared less enthusiastic, saying recently that the country would be better off investing in neglected regional roads and alternatives to roading in cities.
But Northland councils said there was still merit in the proposed four-lane highway.
Far North mayor John Carter said Northland's rural roads did need more money spent on them - but not at the expense of the region's main economic route, State Highway 1 to Auckland.
"The reality is this road is our region's most vital transport link to Auckland, and the rest of New Zealand," Mr Carter said.
Whangarei mayor Sheryl Mai said the rationale for using Northport at Marsden Point to relieve Ports of Auckland should also be pursued.
"This will also meet future export and import requirements for the upper North Island," she said.
Kaipara's acting mayor Peter Wethey said a four-lane highway extending to Whangarei was essential for Northland's economy.
"Given the growth in horticulture in the Far North, the development of key access route to markets is critical," he said.
"Any delay in progressing the highway improvements will be counterproductive. "
Northland Regional Council Chairman Bill Shepherd said the proposed four-lane highway also had advantages for better and safer tourism.
The current road had design issues and a lack of safe passing lanes, he said.
"It forces tourists and commuters to share some of the most dangerous and busy stretches of highway with fully-laden logging trucks."