Since its opening just five years ago, the Toowoomba Bypass has been a source of frustration for truckies like Graeme Hoare.

Mr Hoare, the compliance manager of Oakey-based company Martins Stock Haulage, said up to 50 of his trucks used the bypass each day.

"We've had problems with the bypass since day one," he said.

"We really haven't been able to take full advantage of the bypass because we've always had lane restrictions in place."

When it opened in 2019, the $1.6 billion Toowoomba Bypass — known as the Toowoomba Second Range Crossing during construction — was hailed as a monumental project.

But the road, 120 kilometres west of Brisbane, beset by building delays and workplace violations, has since been dogged by continuous road closures.

The 41-km road, which includes an 800-metre-long viaduct 46m off the ground, was meant to funnel trucks off the streets of Toowoomba.

Shipping containers filled with ballast were installed to protect rock falls on the bypass in November 2022, after cracks were detected in a retaining wall.

Since then, there's been a number of lane closures to allow crews to repair the damaged retaining wall.

Currently, trucks face fines if they use the original Toowoomba Range road and enter Toowoomba without business reasons.

The toll cost is $27.88 for heavy commercial vehicle, $6.96 for light commercial vehicles and $2.81 for cars.

Gary Mahon, the CEO of the Queensland Trucking Association, is calling for the toll price to be slashed until all lanes are open.

Mr Mahon said although it was supposed to reduce the commute time, in many cases that had "evaporated" due to the roadworks and lane issues.

"We want it to work, it is a great benefit to the Toowoomba community, it is a great benefit to the industry … but it needs to be in full operation," he said.

In a statement, a spokesperson for the Department of Transport and Mains Road (TMR) said its contract specified the construction company would repair failures and provide ongoing maintenance of the Toowoomba Bypass for 25 years following completion, at the company's own expense.

"We thank the community for their patience and understanding during the delivery of these important works and apologise for any inconvenience they may cause," the TMR statement said.

The department could not provide a response to calls for a toll reduction as the government is in caretaker mode in the lead-up to the state election.

For Graeme Hoare, the bypass is a necessity, but in its current state, it is stressful.

"It would definitely be 100 per cent safer for all other road users to be able to overtake slower vehicles and not get caught behind us," he said.

Mr Hoare said the decreased speed limit, as a result of the roadworks, was a problem.

"I think the biggest issue is descending down the hill because we move over into the right-hand lane, doing either 40 or 60 kilometres an hour, and that stops the flow of the traffic, creating problems behind," he said.

"People come down in cars and vans and run up behind us very quickly and [this] does create very close calls for our drivers."

Mr Hoare also said the area near the Toowoomba Wellcamp Airport, heading eastbound, should have been dual carriageway, not single lane.

"Unfortunately, vehicles are getting stuck behind us while we climb the hill … and unfortunately these cars are overtaking us when they shouldn't be and there has been some very close calls over in in that area."