Transport Minister Steven Joyce says the toll on the Transmission Gully route will be no more than $3.

Mr Joyce yesterday refused to be drawn on the size of the toll but after reports of high tolls he told Radio New Zealand this morning it would be between $2 and $3.

That would make up about $200 million of the $1.2 billion cost of the gully route north out of Wellington, which is part of a plan for a four-lane highway from Wellington to Levin, costing $2.1bn.

"Most of it would still be paid for out of the National Land Transport Fund, which comes from people's petrol taxes and road user charges," he said.

Mr Joyce said the $2.1bn programme would boost the economy, make travel safer and faster and be a boon for tourism.

The funding is part of the Government's $11b for roads of national significance.

The New Zealand Transport Agency (NZTA) would start work right away on design and consents would use call-in procedures where a minister can fast track processes.

Mr Joyce said all roads involved the private sector and the gully could be a private public partnership.

"There's a range of models and they depend a little bit on the type of project. This one, Transmission Gully, is a very big project but it is also quite a conventional project. There's no really tricky tunnels or those sorts of things, so it may suit something like a design and build (contract)."

That decision would be made by NZTA.

The focus would be on the programme announced so large upgrades of the existing coastal route would not be happening.

"Obviously safety upgrades will continue but in terms of things like by-passes at Pukerua Bay, well look this (the gully route) is the by-pass at Pukerua Bay, it's quite a large one."

Mr Joyce was very confident the programme would go ahead; "The stars have aligned," he said yesterday.

The only issue would be if another Government came in and pulled the funding.

"We get three years at a time in this business, but we will be going flat out in the meantime, and assuming future Governments take the same role that we are taking it will go ahead."

The programme was expected to take 10 years. Mr Joyce was "fairly confident" the budget could be kept to.

The upgraded route from Wellington Airport to Levin was expected to save drivers between 23 and 33 minutes during peak times and between 17 and 23 minutes during the day.

Work to have the highway four-laned would include: duplicating the Terrace and Mt Victoria Tunnels in Wellington City; adding a lane by extending the shoulder on the section of motorway immediately out of Wellington, a new four-lane section - Sandhills Expressway - between Mackays Crossing (just before Paraparaumu) and Peka Peka and four-lane bypasses around Levin and Otaki.

Green MP Sue Kedgley said the programme was a stupid waste of money, traffic volumes were falling and spending so much money was not justified.

Mr Joyce said he accepted environmentalists opposed roads but he did not think New Zealanders would be getting rid of their cars especially as fuel technology provided more alternatives.

While most mayors in the region welcomed the decision Kapiti Mayor Jenny Rowan was "extremely disappointed" by the Sandhills decision and said it would divide her community.