Skip to main content

Mandurah Line now open for passengers after 20-day shutdown to facilitate major works on the Thornlie-Cockburn Link.


Thomas Road to South Western Highway Tonkin Highway extension

Cardup, Darling Downs, Mundijong,


  • Road

    Project type
  • $505 million

    Total budget
  • In Planning

    Project phase
  • Main Roads WA

    Lead agency
  • TBC

    Jobs supported

This project involves extending Tonkin Highway from Thomas Road, Oakford to South Western Highway, south of Mundijong. Approximately 14 kilometres of four lane dual carriageway from Thomas Road to South Western Highway will be installed.

Construction and upgrades of intersections at Thomas Road, Orton Road, Mundijong Road and South Western Highway will also be included.

A grade separated interchange at Bishop Road, catering for the Perth to Bunbury rail line and any future freight rail realignment at Mundijong, will be installed as part of the project.


  • Alleviate pressure on the existing transport network
  • Improved road safety and reduce congestion for all road users
  • Improved freight efficiency, connectivity and travel time

Project map

This map shows an aerial view of the project location.
Project work area

Plan your journey

Avoid disruptions to your journey and plan your trip