Commuter chaos expected as Melbourne kicks off construction blitz

Melbourne commuters have been warned of significant transport delays from today as a summer construction blitz gets underway.

The biggest number of rail replacement buses ever run in the city is now in action as power and signalling upgrades commence on the Cranbourne/Pakenham and Frankston train lines.

Buses are replacing trains between Westall station and Flinders St on the Cranbourne/Pakenham line, and Flinders Street and Moorabbin on the Frankston line from today until January 9.

Upgrade works have also begun on the Monash Freeway between the South Gippsland Freeway and Eastlink.

As many as three lanes will be closed on the major arterial at any one time to allow crews to go about their work.

Authorities have urged commuters and drivers to allow extra travel time over coming weeks.

Work is also scheduled to begin on other projects across the city, including the complete shutdown of Hoddle Street between the Eastern Freeway and Victoria Street from next Sunday.