Kiwirail's been busy over the summer holidays - completing major upgrades across the country

Auckland's metro network saw intensive work on multiple lines - with around 1,800 people working at 89 different rail sites across the city.

Kiwirail's David Gordon says this will support more reliable services and get the network ready for the increased services that'll come with the City Rail Link.

In Wellington, it successfully delivered the largest holiday shutdown ever carried out in the region.

Teams working 24/7 completed work at Wellington Railway Station, as well as on the Hutt Valley and Kapiti lines - among other projects.