Major construction commences on $1bn Tonkin Hwy Extension & Thomas Rd Upgrade

Major construction works are now underway on the more than $1 billion Tonkin Highway Extension and Thomas Road Upgrade in Western Australia. 

This project is one of the biggest road transport infrastructure investments to be delivered in Perth’s south-east corridor, and it is anticipated to create approximately 4,400 local jobs. 

This billion-dollar development will deliver a 14-kilometre extension of Tonkin Highway from Thomas Road to South Western Highway as well as duplicate 4.5 kilometres of Thomas Road between Kargotich Road and South Western Highway. 

The project will not only improve road safety, but it will also help reduce congestion and strengthen freight efficiency for one of Western Australia’s fastest growing regions. 

“This is a once-in-a-generation project that will transform Perth’s south-east, improve safety, and create thousands of critical jobs for Western Australians. 

“This project forms part of our Government’s strong pipeline of infrastructure investment to grow our economy, create jobs for Western Australians and improve the lives of people across our communities. 

“Extending Tonkin Highway will be critical to getting the larger, heavy freight off local roads, making them safer for locals but also improving the efficiency of supply chains and the movement of goods around our State. 

“Together with the METRONET Byford Rail Extension, this project will ensure Perth’s south-east corridor has the right mix of road, rail, cycling and equestrian infrastructure to support its growth into the future,” WA Transport Minister Rita Saffioti said. 

Once the project is completed in 2028, it will deliver several benefits including: 

• Providing safer and more efficient journeys for more than 60,000 vehicles expected to use the corridor daily 

• Remove thousands of heavy vehicles off local roads, reducing pressure on communities in Byford, Armadale, Kelmscott and Gosnells 

• Deliver new grade-separated interchanges, underpasses and roundabouts to improve traffic flow and safety. 

• Introduce new shared paths for cyclists and pedestrians along the entire extension, and equine crossings designed in consultation with local users 

• Complement the METRONET Byford Rail Extension – due to open on October 13, 2025 – ensuring balanced transport choices for the region 

Thousands of direct and indirect jobs are set to be supported through this project, providing a significant boost to the local economy. Opportunities for local suppliers, contractors and First Nations businesses will also be created. 

Early works including site establishment and traffic realignments are already underway, pushing the project forward into the major construction stage with large-scale earthworks, bridge structures and interchange building set to ramp up over the coming months. 

This project is jointly funded by the Australian and Western Australian Governments. 

“The Albanese Government is proud to be investing $749 million in this transformative project. 

“It will not only deliver safer, faster and more efficient connections, but also create thousands of jobs and strong opportunities for local businesses,” Acting Federal Infrastructure, Transport, Regional Development and Local Government Minister Julie Collins said. 

“The Tonkin Highway extension is another example of the Albanese Government and Cook WA Government working in partnership for our south-eastern corridor, making journeys faster and safer. 

“Importantly the growing community in Byford will also benefit from upgrades to Thomas Road, which has struggled with traffic in and out of Byford on neighbourhood streets,” Federal Member for Burt Matt Keogh said. 

The Tonkin Highway Extension will include: 

• Principal Shared Path (PSP) along the eastern side of the highway for the full 14-kilometre stretch, with connections to Thomas Road, Orton Road, Bishop Road, Mundijong Road and South Western Highway 

• Five underpasses and a footbridge at Orton Road for safe crossing by pedestrians and cyclists 

• Grade-separated interchange at Bishop Road to improve traffic flow and safety 

• Roundabouts at Orton Road, Mundijong Road and South Western Highway 

• Underpasses at Abernethy Road and Shanley Road to support vehicle, pedestrian, cyclist, and horse movements 

• Underpass at Gossage Road to support pedestrian, cyclist and horse movements 

• Rail bridges at Bishop Road and Wright Road 

• Noise and visual screening walls, lighting throughout, and improved local road access including emergency egress 

Scope of works for the Thomas Road Upgrade will include: 

• A new grade-separated interchange with Tonkin Highway to improve traffic flow 

• A new 4.5-kilometre shared path on the southern side 

• A signalised equine crossing connecting Byford and Darling Downs bridle paths 

• Intersection upgrades, including: 

• • New roundabouts at Kardan Boulevard and Masters Road/Malarkey Road 

• • Left-in/left-out access at Ballak Place and Briggs Roads 

• • Cul-de-sac at Hopikinson Road (north and south of Thomas Road) 

• • New traffic signals at Plaistowe Boulevard 

• • Reconstructed intersection at Wungong South Road 

• Realignment of the equine path network north of Thomas Road to maintain connectivity 

“As our community continues to grow, this project will provide safer and more efficient connections to improve ease of movement and separate local traffic from heavy freight on our roads. 

“I would like to acknowledge and thank people for their patience and understanding during this time of growth and transformation for our community. 

“As this project ramps up, we are nearing completion of the METRONET Byford Rail Extension, which will not only provide an affordable and convenient commute for locals, but offer a tremendous opportunity for residents to consider public transport during interruptions to our road network,” State Member for Darling Range Hugh Jones said. 

“Our Oakford community has been waiting a long time for this project, and it’s fantastic to see work officially underway. 

“Local families, freight operators and businesses will all benefit from safer journeys and reduced congestion to better connections right across the region,” State Member for Oakford Yaz Mubarakai said. 

Source: Minister for Infrastructure, Transport, Regional Development and Local Government; Government of Western Australia – Media Statements; Main Roads Western Australia