Frankston line commuters will face two months of disruption during a construction blitz next year as two stations are built and three level crossings removed.

The $536 million project will see the heritage-listed Mentone and Cheltenham stations get a major overhaul, while level crossings are removed at Park Road and Charman Road in Cheltenham, and Balcombe Road in Mentone by late 2020.

An artist's impression of the new Mentone station.

The government is avoiding the controversial sky rail option and will instead lower the train line into a trench to improve traffic at the three crossings, which have a total of 38,000 vehicles driving through them every day.

The building work will start in the middle of next year and the stations could each be closed for about four months, while the station car parks at each site could be closed for about 18 months.