Auckland's rail operator says the strike action planned by workers tomorrow is "disappointing and premature".
The industrial action means the 30,000 Aucklanders who commute on trains will have to find alternative transport.
The worker's union is protesting a plan that'll introduce driver only trains, which are already used in several places overseas including Melbourne, London, and France.
The rail operator Transdev says it calls the system driver-door operations.
"Because 'driver-only operations' suggests there's only one person on board that train," says Transdev Managing Director, Michel Ladral. "That's not the case".
Maori wardens and transport officers would still be on carriages at times, with security guards at stations.
But the Rail and Maritime Transport Union believes the system will put lives in danger.
Transdev is frustrated with this, as it says rigorous testing and discussion is still ongoing.
"We are half way through and they are already calling this strike," says Mr Ladral. He also says the union has been asked to work with them during the testing process.
"If they had said to me 'we're worried about jobs' then we would fully understand," he said.
Commuters across Auckland are advised to allow extra time for travel tomorrow.
Auckland Transport chief transport services officer Mark Lambert said: "Roads will be busier tomorrow".
"We're looking at putting additional capacity on key bus routes, but unfortunately due to the short notice of the strike action and the sheer volume of train service affected we haven’t been able to put on alternative bus services for those rail services," he said.
If possible Auckland Transport is encouraging people to ride share, travel at alternative times of the day, or work from home.
The rail workers will be striking for 24 hours from 2am tomorrow.