Shaw Contracting chief executive Joe Luttrell and federal Infrastructure Minister Darren Chester inspected the $44.4 million works on Thursday.

“The project is probably four months ahead of the contractual completion date and we would like to have traffic on the main highway prior to Christmas and do some finishing off works on the old highway in the New Year,” Mr Luttrell said.

The road construction company and Department of State Growth worked together closely to find the root cause of a defective seal, which caused pot holes on about two kilometres of roadworks between Devon Hills and Perth.

“We believe that we have come up with solutions and there will be some rectification works that will be in line with completion in December and moving forward we are working together to ensure that we will get the right solution for the right price as well,” Mr Luttrell said.

The new carriageway will provide two additional traffic lanes which will help to reduce road trauma and improve the efficiency of transport in the region, Mr Chester said.

“The Perth to Breadalbane duplication is one of the largest projects in the Midland Highway 10 Year Action Plan, and once complete will improve safety and efficiency on Tasmania’s key north-south connection,” he said.

“Drivers will soon be able to get to their destinations faster, access to the industrial development adjacent to Launceston Airport will be easier, and getting to the airport will be easier.”

Tasmanian Infrastructure Minister Rene Hidding said the new overpass bridge will allow the highway to pass over the top of new on- and off-ramps, with the underpass for airport traffic to be finished by early 2018.

“In the short term, motorists travelling through the site will notice changes as traffic is temporarily diverted under the newly-constructed overpass near the Breadalbane roundabout,” Mr Hidding said.

“This temporary measure will allow road construction to be completed, ahead of traffic moving onto the full length of the new road later this year.”

The Australian Government is investing $35.5 million and the Tasmanian Government $8.9 million to fund the Perth to Breadalbane Duplication. 

It is part of a joint $500 million investment in the Midland Highway’s Ten Year Action plan.