Melbourne's CityLink and part of the Tullamarine Freeway will be upgraded under an $850 million plan that will create 700 jobs.

The project, unveiled by the Victorian government on Monday, will widen the freeway to boost capacity by a third.

Premier Denis Napthine says the plan will cut travel times between the West Gate Freeway and Melbourne Airport by 16 minutes in peak times.

The project will start in 2015 and is due for completion in 2017.

There will be a freeze on any toll increases for cars, motorcycles and light vehicles for two years while work is underway.

But truck tolls will rise to become consistent with national prices for trucks on other motorways, to help fund the upgrade.

Transurban will fund the $850 million project from CityLink up to Melrose Drive in Tullamarine.

Dr Napthine says the state government is negotiating with the Commonwealth for funding to complete the widening of the roadway from Tullamarine Freeway up to Melbourne Airport, estimated to cost $250 million.

“We’re negotiating with the Commonwealth and we’ll make an appropriate announcement at an appropriate time,” he told reporters.

The premier says the project will complement the East West Link, the Airport rail link and reduce the risk of vehicle accidents.

Under the plan, extra lanes will be added each way between the Bolte Bridge and Tullamarine Freeway, north of Essendon Fields.

There will also be extra lanes on the Bolte Bridge and a section of the West Gate Freeway, eastbound, between the Bolte Bridge and Power Street.