Motorists can expect long delays on Kooweerup-Longwarry Road as road maintenance begins.
Works include the total rebuilt of the road, which is described as being in “poor condition”.
More than 800 vehicles, included about 60 trucks, travel on the road each day.
VicRoads Acting Regional Director Savoula Lidis said the road pavement had significant cracking and pot holes and was in need of frequent repairs.
“We will be rebuilding the road, which will include removing a lot of the existing surface strengthening the underlying pavement, and resealing the road, delivering a safer and more consistent journey,” Ms Lidis said.
Works on the affected area between Bethunes and Andrews Road commenced on 20 March and will run until the end of May.
A second stage of works will begin later in the year between School and McCraws roads.
Upgrades will be carried out between Monday and Saturday from 7am to 6pm.
During road works, a single lane will remain open to traffic at all times, but delays of five minutes are anticipated.
Traffic may also be stopped for up to 10 minutes, where necessary, and surrounding areas may be affected by machine dust and noise.
Ms Lidis thanked the community for their patience while the works were carried out.
“We’re working to improve the condition and quality of our south-east roads so that people can get to where they need to go safely,” Ms Lidis said.
She said the upgrade would benefit the local communities of Catani, Bayles and Koo Wee Rup.
