After 40 years, commuters may well experience traffic congestion easing up in Melbourne with the scheduled opening of the Peninsula Link on Friday.

Initially thought to open on Jan 28, Australia Day, the 27-kilometre Peninsula Link freeway will connect the EastLink in Carrum Downs and the Mornington Peninsula Freeway at Mt Martha. It will be accessible to commuters between 4 a.m. and 6 a.m. on Thursday, and then becomes fully operational by the peak hours of Friday morning.

The presence and eventual implementation and operation of the $759-million Peninsula Link will lessen by 17 minutes the travel time Mount Martha and Carrum Downs, and will save up to 40 minutes during peak times, Premier Ted Baillieu said on Wednesday.

"Peninsula Link will give people the choice to bypass the nine sets of traffic lights and six major roundabouts that exist on the current route," Mr Baillieu said.

"A lot has changed on the peninsula over this time, with record population growth. Melbourne's newest freeway will assist these communities to spend less time in traffic and more time with family and friends," he added.

Terry Mulder, roads minister, at the same time announced that 70 per cent of the 25 kilometre bicycle and walking path along the link will likewise be opened on Friday, while the other sections will open in the coming months.

Sen-Constable Rob Hardy from the Hastings Highway Traffic Patrol said the length of the freeway will be monitored by six speed cameras and the freeway itself will be under constant 24-hour surveillance.

The 27 kilometre road has been under construction since 2010.