Buses have replaced trains between Melbourne and Ballarat, and also Sunbury and Melbourne due to Regional Rail Link Project works.
Set to create an extra 23 suburban and 10 regional services at peak travelling time, the Regional Rail Link Project will see dedicated regional tracks allowing those travelling on the Ballarat line to avoid congestion with suburban trains.
Victorian Public Transport Minister Terry Mulder said that as well as improving train frequencies, the Regional Rail Link would lay foundations for future expansion of the rail network.
Major works will be undertaken between Southern Cross Station and Deer Park and include, track installation and station upgrades.
Commuters have been told to leave up to 45 minutes additional travel time during the nine days of rail works, with temporary timetables running over the construction period.
Trains are expected to be running again from Sunday January 13.