KiwiRail spent almost $1.3 million over 12 months replacing trains with buses on its Wellington rail network.
Figures released to Radio New Zealand under the Official Information Act show KiwiRail brought 5,120 buses in the year to June, costing $1,294,818.
The company says replacements on some services were planned as part of its $500 million upgrade of the network.
The figures also reveal there were 338 technical failures, such as points and signal faults in the past two years, and KiwiRail received 335 complaints regarding delayed or cancelled services.
KiwiRail gives compensation on a case-by-case basis, but says feedback from passengers indicates they would prefer improvements to services and facilities rather than getting money back.