KiwiRail is shutting passenger services in Auckland and Wellington over Labour Weekend to make progress on major rail projects and maintenance work.
Trains will not run from Saturday 21 October in Auckland and Sunday 22 October in Wellington to Monday 23 October (inclusive). Buses will replace trains over this period.
KiwiRail spokesperson David Gordon said KiwiRail used public holidays as a shutdown period because far fewer people needed to use the trains then.
"The Auckland metro network is undergoing a massive transformation ahead of City Rail Link (CRL) opening, which will mean more frequent, reliable and convenient passenger trains for Aucklanders across the city.
"Our improvement work in Auckland also supports getting more goods on rail in the Golden Triangle - Auckland/Hamilton/Tauranga - the busiest freight route in New Zealand.
"We've still got a huge amount of work to do and need periods of uninterrupted access to the network, like Labour Weekend and our usual Christmas-New Year network closure.
Gordon said KiwiRail appreciated the impact of the shutdown on Aucklanders, but it would allow contractors to work more productively and complete the work in good time.
KiwiRail will also be doing upgrades on parts of Wellington's rail network over the long weekend.
"While commuter trains won't be running, there will still be rail vehicles out on the tracks - so please always remain vigilant when you drive or walk up to a level crossing and look both ways before you cross," he said.
The Auckland work - which will be carried out around the clock in some areas - included the new third main line between Puhinui and Middlemore, upgrades at Ports of Auckland, the extension of the electrified network from Papakura to Pukekohe and new stations around Drury.
There would also be slip remediation work on the Western Line, the Manukau Branch Line and around Parnell, as well as track and general maintenance work across the network.
Stage 3a of the rail network rebuild will begin on the Western Line between Newmarket and New Lynn.
City Rail Link will continue major track works at Waitematā (Britomart) and Maungawhau.
In Wellington, trains will run on Saturday 21 October. Renewal work is continuing to raise the standard of the Wairarapa Line. Tracks and signals are being improved around the approach to Wellington Railway Station.