Noske Group is one firm hoping to run the vehicles 24 hours a day, six days a week to help move more than three million tonnes of woodchips each year to the Port of Portland.

The plan, according to Noske Group executive director of operations Tony Noske, would mean fewer trucks on the road at a time - particularly when school buses are running.

"I wouldn't want to be a mother on a country property wondering whether the kids are going to come home at night," said Mr Noske, who is based in Melbourne but used to live in the Green Triangle area.

The relative lack of traffic on the highways at night made it an ideal time to run the trucks, he said. "The more hours you've got to do it the less trucks you need to do it," he said.

He played down suggestions that noise from the late-night freight traffic would upset local communities.

"Heavy traffic would be on the Princes Highway and the Henty Highway and there's not too many communities on those roads that are going to be affected," Mr Noske said.

Like a number of transport companies, Mr Noske's firm has designed a new truck which he said met the State Government's stringent assessment criteria for the "high productivity freight vehicles" (HPFV).

In April the Victorian and South Australian governments announced plans to allow HPFVs to use the Princes Highway between Heywood and Mount Gambier, and the Henty Highway between Hamilton and the Port of Portland, as part of the $340 million Green Triangle Freight Action Plan.

The trucks can be up to four metres longer than a standard B-double, reaching a total length of 30 metres.

They will have to include safety features such as electronic brake and stability control, as well as improved "under-run" protection for other vehicles.

The trucks will also have to meet cleaner emissions standards, and must produce less noise than current B-doubles.

Glenelg Shire Mayor Geoff White was unaware of Noske Group's 24-hour transport proposal.

"It's of great interest to us if transport companies have got aspirations to operate 24 hours a day because we have to know about it," he said.

Cr White repeated calls for road upgrades to be completed before the bigger trucks took to the highways and said delays in the harvest as a result of the collapse of Timbercorp and Great Southern may "create an unexpected opportunity" for works.