A four-lane highway from Wellington to Levin will near completion in a decade, but motorists may have to pay $3 to use Transmission Gully in order to get it built sooner.

The Government announced yesterday that it would spend up to $2.4 billion upgrading State Highway 1 from Levin to Wellington airport.

The unprecedented regional roading project will add four new sections of highway, including the $1.025b Transmission Gully, probably funded in part by tolls.

A four-lane expressway will be built on the Kapiti Coast, bypasses built around Levin and Otaki, two new tunnels drilled beneath The Terrace and Mt Victoria in Wellington, and roads transformed around the Basin Reserve.

The entire project will be completed in three phases, with construction work to begin in three years. Resource consents will be sought within 18 months and will be fast-tracked by the Government.

Once completed, the upgraded SH1 is expected to cut travel times by up to half an hour during peak times, and up to 23 minutes at other times.

But it will see at least 50 properties – and more than 25 homes – bulldozed and one council defied.

Transport Minister Steven Joyce said the project would create at least 650 jobs.

"I think we have a once-in-a-lifetime opportunity to build a fit-for-purpose highway connection between our capital city and points north. I am very confident [the projects will happen]. The stars have aligned."

At least one part of the project is already proving divisive.

A plan to build a new "Sandhills Expressway" along the old Western Link Rd designation from McKays Crossing to Peka Peka has angered Kapiti Coast District Council, which says it will split communities. "This will damage the district for ever," Kapiti Mayor Jenny Rowan said.

In Wellington, tunnels beneath Mt Victoria and The Terrace will cost $217m and $150m respectively, and $36m will be spent improving the Basin Reserve area.

The first project will probably be the opening up of shoulder lanes between Ngauranga and Aotea Quay during peak times, at a cost of $29m.

Wellington Mayor Kerry Prendergast welcomed the massive roading project, despite having been cool on Transmission Gully in the past.

"This addresses our main concern, which had been that Transmission Gully shouldn't go ahead at the expense of improvements in Wellington, which would benefit many more people."

The Ngauranga to Aotea Quay improvements and the Basin Reserve project would "benefit thousands of people every day and it is right that they are given priority status".

Greater Wellington regional council chairwoman Fran Wilde said her council was committed to helping the new roads get built.

"For the first time we've had an acknowledgement of the importance of this route."

Porirua Mayor Jenny Brash said Transmission Gully would benefit the entire country. "We've been waiting for decades for this announcement to be made and it's wonderful that it has now been confirmed."

It is the first time the entire stretch of highway from Wellington Airport to Levin has been developed as one grand project, and the first time total funds have been allotted for Transmission Gully.

However, motorists will probably have to pay to use Transmission Gully.

Mr Joyce yesterday refused to speculate on how much motorists could be forced to pay to use the new 26-kilometre stretch of highway, but told Parliament it was unlikely to exceed $5 a trip.

But after reports of high tolls Mr Joyce 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 $2.1b.

"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.

Work is expected to begin on the Gully in 2012, with completion as early as 2018. However, tolling could shorten that timeframe.

- with NZPA

WHAT $2.4 BILLION BUYS YOU

Phase one:

* Sandhills Expressway, a four-lane highway from McKays Crossing to Peka Peka, $380 million to $500m.

* Peka Peka to Otaki, including adding two lanes and establishing an Otaki bypass, $215m to $355m.

* Basin Reserve, includes improvements to the highway to the north of the Basin and separating east and west traffic, $36m.

* Ngauranga to Aotea Quay improvements, using shoulder lanes during peak hours to ease congestion, $29m.

Phase two:

* Transmission Gully, between Linden and McKays Crossing, $1.025 billion.

Phase three:

* Doubling the number of lanes between Otaki and Levin, building a Levin bypass and more passing lanes north of Levin, $140m.

* Wellington Airport to Mt Victoria Tunnel, $217m. Includes making Ruahine St four lanes, installing traffic lights at Wellington Rd and building a second tunnel beneath Mt Victoria.

* Second Terrace Tunnel, $152m.