Duplication works along a section located between Warncoort and Ballie Street in Colac East have begun as part of the initiative.
The full development will see the construction of a new two-lane carriageway, as well as the rehabilitation of the existing carriageway to create a four-lane divided road.
Federal Minister for Infrastructure and Transport Darren Chester said: “From Winchelsea to Colac, the highway is a two-lane single carriageway with narrow sealed shoulders.
“This upgrade will tackle the problem of poor visibility and terrain, which leads to motorists becoming frustrated and undertaking dangerous overtaking manoeuvres.”
The project is expected to facilitate traffic movement and result in safer journeys.
Princes Highway West serves as a key route for regional commuters, freight movement and tourists.
Victoria Minister for Roads and Road Safety Luke Donnellan said: “The Princes Highway Duplication project is a crucial investment for residents and farmers who reside along this corridor, which is also an important part of the state’s tourism infrastructure as a gateway to the Great Ocean Road.”
The road duplication works from Winchelsea to Colac initially began in the mid-2015.
Member for Western Victoria Gayle Tierney noted that the project is expected to be completed in late 2019, subject to weather conditions.
The project is being equally funded by the federal and state governments.