A walk along State Highway 1 north of Kaikoura reveals the extent of earthquake damage to the road.

Repairs to State Highway 1 and the associated rail line along the coast north and south of Kaikoura will cost up to $2 billion.

Transport Minister Simon Bridges announced on Thursday the Crown would foot the bill for the "very complex" repairs of the road destroyed by the magnitude-7.8 earthquake of November 14.

Bridges said he was confident limited access along the route would be restored in about 12 months.

GEORGE HEARD/Stuff.co.nz State Highway 1 South of Kaikoura close to opening.

He said the existing coastal route would be restored but with additional improvements to increase safety and resilience.

READ MORE:

* SH1 south of Kaikoura won't open this week, but it isn't far away

* Southern sections of earthquake-hit State Highway 1 'could reopen in weeks'

* Crews working to clear slips on SH1, restoring access for local residents

* Inland road to Kaikoura could open by the end of next week

"Since the day of the earthquake, restoring access to Kaikoura has been our number one priority. Agreeing to restore the coastal route demonstrates our ongoing commitment to getting this region back on its feet as quickly as possible," Bridges said.

SCOTT HAMMOND/FAIRFAX NZ The railway line is suspended in midair near Waipapa Bay, north of Ohau Point.

He said the Crown would pay for the work needed. Estimates put repairs costs between $1.4b and $2b.

Emergency legislation passed last week would cut red tape and an Order in Council was being prepared to accelerate the reinstatement of the highway.

Meanwhile, the NZ Transport Agency was repairing and maintaining the alternative route through Springs Junction and Lewis Pass which had seen a massive increase in traffic, especially heavy freight travelling between Picton and Christchurch.

GEORGE HEARD/FAIRFAX NZ State Highway 1 South of Kaikoura is going to be open well in time for Christmas with workers clearing the final slip blocking the main route into the quake-hit town.

The agency was also working with local government to repair and maintain the Kaikoura emergency access route – the Inland Rd – and bring other roads back into service in the leadup to Christmas.

Dave Brash, of NZTA, had taken on the role of national transition manager under the new legislation.

Brash said the agency hoped to start work on the slips north of Kaikoura early next year, possibly starting on January 4 if emergency consents were granted from the council.

SCOTT HAMMOND/Stuff.co.nz Belinda Girl and Maurice Flanagan will be very happy when earthquake damaged SH 1 repairs get under way.

"The big challenge is ... that we don't know exactly the size of those slips, how much we are going to have to move," Brash said. "Until you get in there you don't really know the true nature of it."

Geotech experts were already looking at the sites to get a clearer picture of what was required, Brash said.

Multiple slips would be done at once, which meant getting access around the points for large machinery.

Prime Minister Bill English visited Kaikoura on Thursday, telling the community it did not have to worry about "wrangling away" with trade-offs over projects elsewhere in the country.

"We want to be absolutely clear we are committed to reopening that route as quickly as possible," he said.

While happy with the funding announcement, Kaikoura residents raised concerns about how road repairs had progressed so far. Some called for an inquiry into the handling of restrictions on the Inland Rd route.

Kaikoura dairy farmer Simon Mackle said he felt Kaikoura had been "unnecessarily strangled" by the way the road had been managed.

Others felt bureaucracy had got in the way of getting on with the job, in particular the highway north of Kaikoura, where local knowledge could have helped reinstate some form of access for the isolated communities.

With the funding now in place, works on the northern stretch of the highway look set to begin on January 4.

KiwiRail chief executive Peter Reidy said the Government's commitment to restoring road and rail services was welcome news for freight movers.

No date was available for when the main north line might re-open, but Reidy said work would begin immediately.

"Our job now is to try to make that happen as quickly as possible, to keep New Zealand moving and help grow the economy," he said.

Engineers had been assessing the important freight line since the earthquake, which closed the railway between Spring Creek, north of Blenheim, and Christchurch.

The picture gathered by the engineers provided a detailed picture of where work would begin on the line, which had a total of 21 tunnels and 80 bridges.

Reidy said the state-owned enterprise would look at some temporary fixes to allow for restricted, freight-only services while the permanent line was completed.

"This will ease pressure on SH7 an SH63, as the roads have struggled under the influx of freight trucks during the peak period," he said.

KiwiRail moved more than 1 million tonnes of freight a year between Christchurch and Picton, the equivalent of 80,000 trucks.

"While there will be time delays on the route once opened, it will offer a reliable, cost-effective service with fewer emissions for our customers while taking heavy vehicles off the roads," Reidy said.

The Coastal Pacific passenger service would also be re-instated, however the timing of when that would happen was unclear, he said.

Road Transport Forum chief executive Ken Shirley said the extra distance through the Lewis Pass added additional costs of up to 25 per cent for freight movers.

The announcement SH1 would be re-opened with limited access within 12 months was good news, but not unexpected for the industry.

"In the first weeks it was pretty clear it wasn't going to be a matter of a few weeks or months," Shirley said.

The strain the closure of SH1 had put on other routes, such as the new main freight line through Lewis Pass, showed the importance of having a resilient transport network, he said.

Because of the uplift of the seabed around Kaikoura, Shirley said it might be possible to rebuild the road wider and further away from any potential slips. He also thought the closure, regardless of when SH1 re-opened, would have a permanent impact on the way freight was moved.

Pacifica Shipping had doubled the amount of freight it was shifting between Auckland and Christchurch since the earthquake, Shirley said.

The rise of coastal shipping could continue after the highway was re-opened, depending on pricing and what other alternatives there were, he said.

"What we really want to see are transport modes competing on their comparative advantages, without subsidisation."

A drive south, one month on

Reporter Jeffrey Kitt sees firsthand the massive job facing roading crews.

Collapsed rock face, ejected seabeds and unhinged train lines; destruction is never far from view heading south from Blenheim.

The scars left behind are nowhere near to closing on the South Island's most significant thoroughfare.

The drive towards earthquake-stricken towns Seddon and Ward may offer the illusion of normality with largely untouched road surfaces.

But this mirage is quickly marred by road crews working furiously to reinforce a crumbling wall of rock shortly out of Ward.

The manned checkpoint at the Flaxbourne Tearooms in Ward, to stop unnecessary traffic heading south, is no longer, replaced instead by a sign which reveals the road will end in 45 kilometres.

From this point onwards, the traffic noticeably thins out.

The Kekerengu Store, about 20km before the dead end, is normally bustling this time of year but instead it has been closed for a month with no confirmed reopening date.

The highway officially closes just past Clarence Bridge, where the real damage becomes evident.

Tarseal becomes gravel as a makeshift trail forged through a road slips in two.

Traffic cones herd traffic into the right-hand lane as the southbound side has completely fallen away just north of Waipapa Bay.

Parts of the rail line are suspended in midair.

A police patrol passes and inspects identification. The officer says he has barely seen a soul that morning.

Like residents along the highway, he too is confused as to why work has yet to begin repairing the stretch of SH1 north of Kaikoura.

The drive becomes more of a crawl as huge boulders forced from the hills pepper the northbound lane.

And the slower the drive, the stronger the stench of decaying sea life.

A massive mound of dirt crosses both lanes to prevent going further south than Okiwi Bay.

Seeing the slip in person reinforces how big a job lies ahead for roading crews.

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