Key connector’s scars now healed

Devastating bushfires in 2019 severely scarred one of Queensland's most important mountain passes.

Cunninghams Gap, the gateway to the Southern Downs, is no ordinary road.

It’s a critical national freight route, linking southern Queensland rural communities with the major centres of Ipswich and Brisbane.

But extensive damage from the bushfires left a two-kilometre section of the road facing a slow and painful rehabilitation. 

Steep slopes became unstable and rockfalls, while occasional, were still a constant concern..

However, keeping the Gap open for traffic was non-negotiable and, thanks to careful planning from Queensland’s Department of Transport and Main Roads (TMR), Cunninghams Gap never closed while the work continued.

Top of mind during the many months of planning before works got underway was the question: how do you tame a mountain that sheds its rocks?

TMR’s innovative solution involved building a defence in layers:

• A one-kilometre rockfall fence, almost seven metres tall, to catch falling debris before it reaches the road.
• About 20,000 square metres of drape mesh to blanket the slopes above.
• More than 1,200 cubic metres of shotcrete sprayed onto rockfaces.
• Over 1,300 soil nails and rock anchors grouted deep into the mountainside.
• Seven retaining walls built below the eastbound lane so the fence could stand at road level.

From October 2023, crews worked in the narrow confines of the Gondwana Rainforests World Heritage Area and, with almost no room to spare, built upward.

This vertical approach, rarely seen on Queensland road projects, saw five tower cranes raise two of seven retaining walls that let crews work safely in tight terrain and reduce the need for long lane closures.

Helicopters were used to reach areas inaccessible to the cranes, with more than 90 heli-lifts carrying materials to the worksite.

During the works, a close partnership with the Queensland Trucking Association (QTA) saw 21 heavy vehicle safety videos released on the TMR and QTA YouTube channels to help freight operators navigate the corridor.

Completing the landmark reconstruction project took almost three years of painstaking work and somehow, TMR managed to keep at least one lane open at all times.

With works complete, drivers are noticing the difference, especially near the final bend below the crest near the Allan Cunningham monument, where heavy vehicle breakdowns once caused regular havoc. 

TMR has lowered the steepness of the gradient to allow for a smoother turn and fewer breakdowns.

Improvements also include two new emergency bays at the Crest Carpark for incident response, improved access across Gap Creek Bridge for emergency teams to reach broken-down vehicles, restored pavement east of the Gap Creek bridge, and five CCTV cameras monitoring slope stability, road hazards and traffic conditions.

Jointly funded by the Australian and Queensland Governments through the Disaster Recovery Funding Arrangements (DRFA), the Cunninghams Gap project has made this vital transport route safer, stronger, and better able to withstand whatever the future brings.