Tonkin Highway Extension

Thomas Road to South Western Highway

In planningFuture

Extend Tonkin Highway an additional 14 kilometres.

Tonkin Highway intersection

What's happening

Planning and development

Development work is continuing in 2022 to incorporate additional scope items and mitigate project risks. Activities underway include:
  • Incorporating new scope into the project’s base case design
  • Additional traffic modelling
  • Additional geotechnical investigations
  • Further groundwater monitoring
  • A Noise Study to determine height and location of noise walls, and a Visual Screening Assessment
  • Road Safety Audits and reviews
  • AusRAP Road Safety Assessment and Star Rating
  • Finalising the Access & Connectivity Strategy including Fire & Emergency access and egress
  • Engaging service providers (Western Power, Water Corporation etc) to determine requirements
  • Updating the Urban Design & Landscape Framework to reflect additional scope and design development
  • Sustainability integration
  • Crime prevention through Environmental Design
  • Heritage interpretation along the PSP
  • Operation Efficiency Audit

A procurement strategy and timings are currently being developed in partnership with industry.

Read more in the September 2022 Project Update.

Sustainability excellence

The project’s planning recently achieved a ‘Bronze’ Rating under the Infrastructure Sustainability Council Infrastructure Sustainability (IS) Rating Scheme, with a score of 27.2 points across 16 credits. The credits included Urban and Landscape Design, Resilience, Climate Change, Resource Efficiency, and Stakeholder Engagement.

The Bronze rating recognises the joint efforts of the project team of Main Roads and Arup to plan for best practice outcomes in sustainability. Main Roads and Arup jointly submitted the Tonkin Highway Extension project for nomination for the Infrastructure Sustainability Council’s (ISC) Annual Award and have been shortlisted as finalists for the Award.

The Bronze rating will set the Delivery team up to achieve the mandated Silver ISC rating for the design and construction phase of the project.

pressure on surrounding roads


travel times


road connectivity

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Acknowledgement of country

The Government of Western Australia acknowledges the traditional custodians throughout Western Australia and their continuing connection to the land, waters and community. We pay our respects to all members of the Aboriginal communities and their cultures; and to Elders both past and present.

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