Buses are replacing most trains services on all Wellington lines this weekend while track maintenance and upgrade work is done.
KiwiRail said work would resume this weekend on an upgrade programme, including replacing the overhead power system, renewing track in tunnels and improvements to the Wellington and Plimmerton train stations.
"Due to Covid-19 and the alert level restrictions, upgrade work and non-essential maintenance work stopped across the network," chief operating officer Todd Moyle said.
"To carry out this vital work we need both safe access to the tracks and enough space for our teams to work. Unfortunately, this means some disruption for those using train services is unavoidable."
Buses will also replace trains on on lines during the week.
The project is the largest set of works on Wellington's rail infrastructure in 60 years.