Melbourne Airport authorities have approached the state government with a draft plan to mount an $80 million worth airport road expansion that it would want to start constructing sometime in 2013.

The proposed expanded new six-lane, 3.7km road of Airport Drive would free up Tullamarine freeway from traffic congestion since commuters would get access to the airport directly from the Western Ring Road. It likewise effectively reduces the number of cars plying Melrose Drive.

Contained in a draft master plan presented on Monday, the proposed extension would initially support a four-lane divided road that could later on be expanded to six lanes. It holds a rail link reserve in the median strip. It likewise has a shared pedestrian and cycling path.

"The Airport Drive extension will provide a second entry point into the airport precinct and relieve some of the congestion on the Tullamarine Freeway and reduce the amount of airport traffic using Melrose Drive," Anna Gillett, Melbourne Airport spokeswoman, said.

Airport authorities said the plan has been released for public consultation. If approved by both state and federal governments, construction can begin next year. It will take an estimated 21 months before the road gets finished.

In 2009, according to traffic modelling statistics, there were 93,000 vehicle trips a day at the airport, where on weekdays between 7am and 9pm, it handled a whopping 4,000 to 5,000 vehicles an hour.

And from 109,000 a day in 2012, the growth in the number of vehicles the Melbourne Airport is expected to handle by 2033 could rise to 230,000, according to the 20-year draft master plan that sets out Melbourne Airport's strategy.

In 2026, the number of people travelling to the hub is expected to reach 170,000 daily, with Airport Drive holding 25,000 vehicles, entering and leaving the airport per day.

As to the rail link, while Melbourne Airport strongly supports its creation, it said that its eventual construction lies in the hands of the state government.

"Melbourne Airport absolutely supports a rail link to the airport," Ms Gillett said. "(That's why) there is provision for a rail line in this extension of Airport Drive and this has been the case for a number of years."

"We are working with the government on a feasibility study for that, however it is up to the government to build that rail link," she said.

Premier Ted Baillieu, for his part, said the state government had committed $6.5 million to a study on a rail link to the airport.

"It's not a simple exercise to simply drop a rail link into an airport," he said.

Matthew Guy, Victorian planning minister, defended the state government is highly studying the feasibility of the rail link proposal.

"But it's not just a simple discussion because there are issues obviously around whether you elevate, whether you go underground, whether it's broad gauge, whether it's standard gauge, whether it's interacting with electric," he told ABC News.

"There's a whole range of issues that have got to be looked at."