Business is booming along a stretch of South Island highway that became the main north-south route after the November earthquake.
Business owners in St Arnaud and Murchison say turnover has doubled and they struggle to cope with the crowds queuing for fuel, coffee, food and accommodation.
Elaine Richards, who owns the St Arnaud Alpine store an hour south of Nelson, bought the business a year ago.
She has lived in St Arnaud for some time and was a regular at the village store and petrol station.
She said it was just beginning to calm down as the new school term approached.
While circumstances were bad for Kaikōura - State Highway 1, from Mangamaunu to Clarence, remains closed or has restrictions - they were good for St Arnaud where it was difficult to keep a business going.
"This was an average business before, but now it's a good business," Ms Richards said.
She said turnover had doubled, helped by fuel sales.
Alpine Lodge co-owner Leighton Marshall said the constant flow of large freight trucks past the front door continued to grow.
He said the lodge and restaurant could have been twice the size and still not coped with the new demand.
"It's been a little bit stressful at times. We've done numbers like 180 (through the restaurant), which puts a lot of pressure on the kitchen. We've also had a lot of the [construction company] Fulton Hogan crews in for dinners and we've been making cut lunches for them as well."
Mr Marshall said it was clear from talking to business operators in Nelson that the area, which is better known as a destination than a stop-over, had benefited from the diversion of tourists.
"It's a bumper tourist season happening in New Zealand, but a lot of traffic coming in from Picton - if they're organising their trip now they're deciding to go up and over the hill to Nelson. They'll then explore the Abel Tasman and Golden Bay and the same's happening in reverse - traffic coming from Christchurch is heading on up to Nelson," he said.
'Murchison has really flourished from this'
Further south in Murchison, the queue for fuel stretches down the road. Bus loads of tourists wait patiently at restrooms and cafes, and an endless stream of trucks rattles through the junction town.
Elizabeth Riley moved from Wellington four years ago and owns bush walk business Natural Flames, where people hike to flames in the forest that have been burning for a century.
She said the busy season boosted by random bookings was tempered only by the less-than-great weather.
"Probably more significant for us is those tour companies that have said, 'right, we're re-directing our tourists through Murchison and the Lewis Pass and we'd like to find out what's available there'.
"So they book in advance and they're bigger groups, which is good for us," Ms Riley said.
Murchison teen Maddie Kinzett has used the influx to test the market for her handmade jewellery. The 13 year-old had set up a stall outside a busy cafe, and while the time spent making the jewellery had filled the school holidays she was not sure it was a career in the making.
An 1890 wooden building off Murchison's main street is now the home of vintage store Dust & Rust. The building once housed horses and stage coaches in the gold rush era.
It was the evacuation centre for the town after the magnitude 7.8 earthquake of 1929. That earthquake killed 15 and toppled structures on the West Coast and in Nelson.
Katharina Erdl and her partner have run the store since late 2014, selling artefacts from the area and around the country. She said they had been so busy they worked harder to source items for the store.
"It's been really good. Murchison has really flourished from this."
She said once State Highway 1 fully opened again through Kaikōura, the reputation of places like Murchison had been enhanced enough that business would continue to grow.