PASSENGERS on the Sydenham, Ballarat and Bendigo train lines will face delays over summer as part of Regional Rail Link works.
Buses will replace Ballarat and Bendigo V/Line trains between December 28 and 30 and January 4 and 13, the Herald Sun reports.
Some will face delays of up to 45 minutes.
Passengers on the Sydenham line will also have to catch buses between Albion and Footscray stations in the same period.
Public Transport Minister Terry Mulder said undertaking the works, which include bridge modification, track installation, tunnel strengthening and station upgrades, during the quieter summer period was the easiest way to minimise disruption.
"We ask commuters to understand and accept the fact there may be some delays during this period of time," he said.
"Importantly all affected lines are scheduled to be open for New Year's Eve."
He said previous shutdowns had gone "extremely well".
"We expect . . . carrying out these shutdowns during the quieter period of the year for commuters will also go extremely well," he said.
"There has been a lot of work, an awful lot of planning being put into this project . . . to make sure that these disruptions cause as minimal amount of inconvenience.
"There is no other way to approach this other than to have continual shutdowns through the night or on weekends right throughout the year, and to take advantage of the Christmas break period to conduct this work we believe is the best opportunity to make sure we don't have those negative impacts, particularly on commuters travelling in and out for work on a regular basis."
Sydenham and Bendigo passengers were unexpectedly forced on to buses last month after a signal fault during planned regional rail works caused chaos.
Regional Rail Link CEO Corey Hannett said he was confident there would not be a repeat of the unexpected delays, which could cause problems for commuters trying to come to Melbourne for New Year's Eve.
"We will definitely hand back the tracks when we say we will," he said.
Metro CEO Andrew Lezala said the metropolitan train operator supported the $5.3 billion project as it would provide a huge capacity boost.
Read more at the Herald Sun.