Western Australia’s Tonkin Gap Project is officially complete

The Tonkin Gap Project and Associated Works has officially been completed, alleviating pressure for motorists on Tonkin Highway between Collier Road and Dunreath Drive.

GHD, as part of the Tonkin Gap Alliance between BG&E, Georgiou, BMD, WA Limestone, Main Roads WA and Public Transport Authority, designed and delivered a solution to a well-known bottleneck along Tonkin Highway. The project has significant benefits for commuters, path users and the local community with improvements in journey times and amenity. The Alliance was also tasked with delivering the enabling works for the future METRONET Morley-Ellenbrook Line.

Major components of the Tonkin Gap project included:

• Removal and replacement of Broun Avenue Bridge.
• Duplication of the Redcliffe Bridge (now Mooro-Beeloo), comprising a 330m launched structure over the Swan River.
• Upgrades to improve existing interchanges at Great Eastern Highway and Guildford Road.
• A total of 8 bridges and 3 footbridges over the Swan River, Dunstone Road, Railway Parade and Guildford Road.
• 3.1 kilometres of new and upgraded principal shared path along Tonkin Highway.
• Rail-enabling works for METRONET Morley-Ellenbrook Line.
• BMX and mountain bike recreation area under the Mooro-Beeloo Bridge.
• Two dive structures to facilitate the railway entering and exiting the Tonkin Highway median.

We've overcome several challenges during the project, including a constrained project site, variable ground conditions, high groundwater, and traffic management through a busy corridor. A large part of the design was also delivered during the peak of the COVID-19 pandemic, on time and within budget.

In 2023, the Tonkin Gap Alliance achieved a Gold Infrastructure Sustainability (IS) Design rating from the Infrastructure Sustainability Council for the Tonkin Gap Project. This award recognises the success of the entire team in adopting and driving sustainable approaches to drive governance, economic, environmental and social outcomes through detailed design and construction planning.

In June 2024, the project's complexity and significance were also awarded the Master Builders Association of Western Australia's Excellence in Construction Award for the 2024 Best Civil Engineering Works over $100,000,000. 

About GHD

GHD is a leading professional services company operating in the global markets of water, energy and resources, environment, property and buildings, and transportation. Committed to a vision to make water, energy, and communities sustainable for generations to come, GHD delivers advisory, digital, engineering, architecture, environmental and construction solutions to public and private sector clients. Established in 1928 and privately owned by its people, GHD’s network of 12,000+ professionals is connected across 160 offices located on five continents.