The Princes Highway West Action Alliance wants to know "what the bloody hell is the state government waiting for?"
The alliance has launched a television campaign in a bid to find out why the government has not started upgrade works on the highway.
Spokesman Stephen Lucas said there had been many political roadblocks along the way, but the federal and state governments had now finally agreed the work was fully funded after a contribution from both levels of government.
"It has been a very long haul," he said.
"But we finally have the funding agreements we need in place, after many years of lobbying by the community."
Mr Lucas said the ad campaign was designed to encourage the state government to "finally get going, with these much-needed roadworks and improvements".
"The ad is simply echoing what so many people in our community have been saying for so many years now, 'what the bloody hell are they waiting for?' and we think that's exactly the question the Andrews' government needs to take notice of.
"We've got the agreements, now we've got the money, so what more do they need before we see some work happening?"
In the ad, viewers are told the Princes Highway West is in urgent need of an upgrade.
"The federal government recognised how bad it was and committed more than $60 million to fix it, but that was more than two years ago," it states.
The state government "hasn't even started any major works", it continues.
"That's the Victorian state government's job," viewers are told.
"Doesn't the community of south-west Victoria deserve better? What the hell are they waiting for?"
The federal government money includes $60 million for upgrades between Warrnambool and Port Fairy, $80 million for the Green Triangle area and funding that would see changes to the Blue Church intersection near Colac.
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