In the small village of St Arnaud at the southern apex of Tasman and Marlborough, a once-quiet car repair and salvage business is suddenly very busy.
Its owner, Alastair Nicholls, has been hauling out cars that have fallen into potholes riven into a road that was never designed for large volumes of vehicles and heavy trucks.
He said it was common for truck drivers to have to change multiple blown tyres on a single journey and temporary bridges were proving a bit too narrow for some.
"We had a good one the other week. That was a big tandem trailer and he'd had three flat tyres and had run out of spares.
"We had another one the other day when a gentleman had tried to get across a narrow bridge but his trailer didn't quite fit and he tore out all his axles - he ended up with a big sledge really."
Mr Nicholls said roadside rescues on State Highway 63 had increased seven-fold since the road became the main highway after the Kaikōura quake closed the SH1 coastal route.
He said before the quake he was dealing with about two call-outs a week. He was now coping with that number each day within a 100km radius of St Arnaud.
Mr Nicholls said Easter weekend was particularly bad.
"Four of the callouts were destroyed vehicles because of the potholes. Bits were torn off, suspensions collapsed, hubs destroyed - all related to wheels going in potholes.
The transport agency's latest figures show the number of vehicles through the township of St Arnaud has soared from about 400 to almost 2000 each day. At Murchison the number has gone from 2000 to almost 4500.
Heavy trucks passing through St Arnaud have gone from an average 40 each day to almost 600. At Murchison the number has jumped from an average 350 to just over 1000 each day.
The government is spending around $60 million to upgrade and maintain the highway while the estimated $2 billion reconstruction of SH1 through Kaikōura is underway.
Transport Minister Simon Bridges said last month that several sections of the SH63 route have been widened, 36km have been resealed and a further 22km are to be resealed before winter.
Three new bailey bridges have also been installed alongside permanent one-way bridges in the St Arnaud area.
Mr Nicholls said he has bought an extra tow truck and upskilled some staff to cope with what has become a 24-7 service.
"Normally we're a lifestyle business and it's pretty quiet here, but we're now on-call 24-7. I've got great staff and one of them I've put through a course so he can get the licence needed to drive the heavier truck."
The eight-week course costs about $2500.
Mr Nicholls said it costed between $250 and $500 dollars a call-out, but problems could be avoided by people driving to the conditions.
"A lot of the area is not covered by cell phone either so people who need help often have to walk to the nearest shop or flag someone down."
Mr Bridges said a short-range cell phone site is being installed at one site this month to improve mobile phone coverage and speeds have been reduced in high risk areas.
Mr Nicholls said he was keen for things to return to normal, and for the traffic to revert to its former route.
He said he was concerned that safety was being compromised by some drivers becoming too familiar with the road, and driving too fast.
"They're starting to go so fast - some of the trucks - in some areas where there's just not enough room and there's no way they can stay on their side of the road.
The transport agency said work was on track to re-open the Kaikōura route in December.