RESIDENTS have applauded a ban on truckies using the right-hand lane of the Princes and West Gate freeways, but industry has warned the plan may be disastrous for freight.

Transport Workers Union branch secretary Wayne Mader said trucks getting stuck behind cars could slow down the freight industry.

"If cars in those lanes on a 100kmh freeway drive at 70kmh, that means no truck will be able to get the benefits of the flow of traffic."

He said there was also the danger of frustrated truck drivers under pressure being delayed further by traffic.

Victorian Transport Association chief executive Philip Lovel agreed.

"There is likely to be increased overtaking in the left lane," he said. "The key to this plan working is that all motorists need to change their attitudes, not just truck drivers. Motorists need to ensure they are observing the road rules to keep left and keeping up with the speed limits."

Mr Lovel was unsure how the restrictions would be enforced.

"We hope VicRoads and Victoria Police have done their homework on this or it could be a disaster."

But Maribyrnong Truck Action Group president Peter Knight said the restrictions were sensible.

"There needs to be a lane that is just for cars," he said. "It can be really intimidating when it's just a wall of trucks, being squeezed in between two trucks and you can't get past."

A recent RACV survey found 83per cent of motorists believed trucks should be restricted from using the right-hand lane on multi-lane freeways.

Roads and Ports Minister Tim Pallas claimed the restrictions on multi-lane freeways would improve traffic flow and safety for other motorists.

The restrictions will begin mid-year on the Princes Freeway and later rolled out on the West Gate Freeway and possibly other freeways including CityLink.

Mr Mader said the restrictions should be on a trial basis.

Mr Pallas said he recognised the importance of the freight industry to Victoria's economy.

"Trucks do have a place on our roads. But the new restrictions aim to address the significant impact that freight operations have on traffic flow, safety and the liveability."