Leach Highway and Welshpool Road Interchange

  • New grade separated interchange
  • Planning and development now underway
  • Construction works anticipated to begin 2021

Leach Highway graphic 


We are planning to build a new interchange at one of Perth’s most congested intersections in Welshpool.

The preliminary concept for the project includes a:

  • Grade separated interchange at Leach Highway and Welshpool Road with Leach Highway travelling over Welshpool Road;
  • New road bridge for Leach Highway over the Armadale/Thornlie rail line.

Project Update

Extensive planning and project development is now underway to confirm the scope and progress the various approvals to allow for construction.

Activities include:

  • stakeholder consultation to identify and resolve the various issues/constraints 
  • concept design, geotechnical and site investigations, traffic modelling and environmental assessments to inform environmental processes and approvals
  • community engagement


  • 2019-20: Planning and Development
  • Construction timeline is subject to environmental and statutory approvals and finalisation of project scope.

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  • Greatly improve the efficiency of this critical juncture in the transport network
  • Significantly improve travel times and safety for local, regional and freight traffic.


The Federal ($46.5 million) and State ($46.5) Governments have committed funding.

Last Updated: 25 March 2020