KiwiRail is defending its Christmas maintenance schedule in the Wellington region, saying the work would take months to complete otherwise.
The Kāpiti commuter train was replaced by buses around Christmas and New Year to allow for maintenance work.
The buses were plagued by long delays because roads were heavy with holiday traffic, and some passengers waited at stations for more than an hour and a half.
In a just-released letter to Greater Wellington Regional Council, KiwiRail's Wellington Metro manager Michael McKeon said that because the line needed to be closed, it was safer and faster to do the maintenance work during holidays when there were fewer commuters and no freight services.
Mr McKeon said that if the work had been rescheduled for some other time, it would have caused bigger delays for commuters and freight, and could take months to complete.