A four-lane highway from Puhoi to Wellsford is tagged as a possible toll road, meaning those wishing to take the quickest route from Auckland to Northland could be hit by two tolls.

Transport Minister Steven Joyce included the upgrade of State Highway One from Puhoi to Wellsford in a list of seven roading projects the Government has decided are of "national significance" and which it wants completed within 10 years.

The seven stretches of highway will qualify for fast-tracking through resource consent processes and the Land Transport Agency is expected to give priority to them.

Three areas of state highways near Auckland are on it - the 34km Puhoi to Wellsford run, the SH20 Western Ring Route, and the $320 million northbound motorway tunnel under Victoria Park.

The Waikato Expressway, Tauranga Eastern Corridor and the Levin to Wellington stretch of SH1 are in the same category and parts of the state highway to the north, south and west of Christchurch also qualify - but the fate of Wellington's Transmission Gully remains uncertain.

Mr Joyce said he hoped all seven would either be completed within 10 years, or well on the way to it. The Government announced this week that it was boosting funding of state highways to $10.7 billion over 10 years.

Mr Joyce said three current roading projects were candidates for public-private partnerships, with the possibility that they would be tolled - which he said would "accelerate" their progress.

Other potential toll roads are Transmission Gully and Tauranga's eastern corridor. The first two were already tagged as possible toll roads.

Mr Joyce said it was too early to tell whether the Puhoi stretch would be tolled, how much it would be or where a toll might apply - whether on the well travelled strip between Puhoi and Warkworth or further north. Under National's criteria, there must be an alternative free route for motorists to take and tolls must be reasonable.

Rodney Council Mayor Penny Webster said the decision to make the road one of national significance was welcome. She had urged Mr Joyce to reprioritise it, especially the bypass of Warkworth, because although the Northern Gateway had sped up the trip from Auckland, the problem of the bottleneck and long queues at Warkworth on weekends remained.

Changing the 34km stretch into a four-lane highway is likely to cost at least $1.5 billion. The 7.5km Northern Gateway road between Orewa and Puhoi cost $356 million and the toll charge is $2 for cars - travel time savings are about seven to 10 minutes.

Mr Joyce said because it had not been among the previous Government's three-year plan priorities, little work had been done on the actual route or likely costs. Officials were also yet to report back on whether there were any cheaper alternatives to the $2 billion-plus Waterview tunnels project.

Mr Joyce had ordered them to find alternatives because of the cost of the project and the size of the tunnel, which he said could not be widened later for future demand.

Labour transport spokesman Darren Hughes said the announcement was an attempt to divert attention away from National's decision to get rid of the regional fuel tax. He said public transport was suffering because "National's ideology is rooted in tarseal and more and more use of private roads".

Part of the extra funding for the state highways will come from nationwide increases in petrol tax by 3c this October and a further 3c next year. The tax is double that which was initially proposed because of National's decision to get rid of a regional fuel tax.

* Puhoi to Wellsford SH1
* Completion of the Auckland Western Ring Route
* Auckland, Victoria Park bottleneck SH1
* Waikato Expressway SH1
* Tauranga Eastern Corridor SH2
* Levin to Wellington SH1
* Christchurch motorway projects