Police will get up to $5 million each year to help them deal with changes to warrant of fitness rules, which will see them taking on more road policing work.
Changes to the rules will see cars registered after 2000 require WOF checks only once a year, rather than six-monthly. But the Government says police will carry out extra enforcement duties to ensure cars are roadworthy.
The Police Association has raised concerns the move would draw police resources away from other work.
But New Zealand Transport Agency chief executive Geoff Dangerfield says police will receive between $2.5 and $5m annually to help with extra road policing.
"We would expect simple roadside checks on the things that matter - and the things that do matter tend to be brakes and lights and tyres," he told a press conference on Monday.
The Automobile Association says changes to the warrant of fitness regime will reduce unnecessary costs for New Zealanders, without compromising safety.
But the Motor Trade Association, which represents mechanics, says the changes may lead to a loss of more than 2000 jobs and could increase costs for motorists.
DogAndLemon.com website editor Clive Matthew-Wilson said dispensing with the system will "inevitably result in more deaths and injuries".