Currently, all vehicles must have a WoF inspection every six months if older than six years and only annually if less than this.
Tauranga WoF issuer Pierre Koningsveld, who is on the executive committee of the Motor Trade Association, said the changes would be hard felt by the industry and could result in job losses.
"It will affect our industry ... the number of WoFs done will probably drop, the repairs will probably drop, right through the industry through to the guys supplying parts and tyres. It has bigger implications across the board," he said.
"Unfortunately we get vehicles coming into work that should never have been allowed on the road. It's going to be another six months before anything can be done to stop them now."
Mr Koningsveld, from Auto Stop Greerton, said he knew of others in the industry and customers who felt the WoF system should remain as it was.
"But we can't change it now. We have to try and adapt and run with it and see how it performs," he said.
Road safety campaigner and Dogandlemon.com editor Clive Matthew-Wilson said the changes would result in more road deaths, labelling the six-monthly WoF check as a "lifesaver".
"The average motorist will save very little and may lose a lot," he said.
Vehicle Testing New Zealand (VTNZ) chief executive Mike Walsh said relaxing the rules around inspections would require huge investment from other areas, including policing.
"They've hugely underestimated the additional costs," he said.
The changes were likely to see some VTNZ testing stations close and others reduce services, Mr Walsh said.
But the New Zealand Automobile Association welcomed the changes. Spokesperson Mark Stockdale said the decision was a logical result and the arguments for retaining a six-monthly inspection were not as valid as they were decades ago when cars were less safe and reliable.
"With only 2.5 per cent of accidents involving a mechanical defect, and just 0.4 per cent where it's the sole cause, the evidence does not support testing all vehicles every six months, or four times as often as most other countries," Mr Stockdale said.
Euan Philpot, chief executive for theJapan Export Vehicle Inspection Centre New Zealand, which is in the process of taking over 100 per cent of Vehicle Inspection New Zealand shares, said overall inspection volumes would reduce, impacting fees and commissions for inspection services providers. This would result in increased competition and drive consolidation in the industry, he said.
"WoF changes are of the level we expected and will reduce costs to consumers ... the Government makes it clear that it wants vehicle owners to understand that the onus for compliance will shift on to them," Mr Philpot said. "This creates opportunities for vehicle inspection companies to develop new services and build deeper customer relations to increase customer loyalty," he said.
