Reid Highway and Erindale Road Grade Separation

Reid Highway is a key east-west arterial road in Perth’s northern suburbs, linking two major north-south corridors: Mitchell Freeway to the west and Tonkin Highway to the east. Recent investments have focused on upgrading Reid Highway by progressively replacing at-grade signalised intersections with interchanges that enable free-flowing traffic.

The intersection of Reid Highway and Erindale Road is the last remaining at-grade intersection between Mitchell Freeway and Tonkin Highway. It plays a vital role in the broader road network, facilitating access to residential suburbs such as Hamersley and Warwick, as well as the Balcatta light industrial area.

This intersection carries approximately 83,000 vehicles per day and was ranked the most congested intersection in Western Australia in 2023/24. It also recorded the highest number of reported crashes in the Perth metropolitan area.

The project will see the last at-grade signalised intersection on Reid Highway at Erindale Road replaced with a bridge carrying Erindale Road over Reid Highway

By taking Erindale Road over Reid Highway, the project will improve safety by replacing the signalised intersection with a grade-separated interchange, reducing the likelihood and severity of crashes.

The project also proposes to significantly improve the daily commutes for residents in Balcatta, Hamersley, Warwick, and other northern suburbs, by easing congestion and delivering safer, more efficient roads.

Other key benefits include:

• Improved travel time reliability and productivity for freight traffic, particularly for access to the Balcatta industrial area
• Greater travel time consistency for all road users
• Improved accessibility and connectivity between Reid Highway, Mitchell Freeway, and Erindale Road
• Upgrades to the Principal Shared Path network, improving safety and connectivity for vulnerable road users including, pedestrians and cyclists.

 

Protecting the environment

Main Roads is dedicated to reducing environmental impacts throughout the planning, construction, and maintenance of road projects. Beyond minimising harm, we actively offset unavoidable impacts by procuring and rehabilitating suitable land parcels, ensuring a positive contribution to environmental sustainability.

We are undertaking studies and field assessments to understand environmental values within the proposed project extent to inform mitigation strategies.

The project will be referred to both the Commonwealth and State environmental regulators below:

• Commonwealth Approvals: Main Roads referred the project to the Commonwealth Department of Climate Change, Energy, the Environment and Water (DCCEEW) in April 2026. DCCEEW will invite public comment on the referral before deciding if the project is a controlled action and therefore whether or not it requires a formal assessment in accordance with the EPBC Act 1999. The public comment period is now open and will be open for 10 business days via the DCCEEW Public Portal until 20 May 2026. Visit the DCCEEW Portal here.
• State Approval: The project will be referred to the State Environmental Protection Authority (EPA) in July 2026. The EPA will invite public comments and determine whether the project will be assessed under the Environmental Protection Act 1986 (EP Act).We will provide an update when the project is referred to the EPA.

Managing noise

Potential noise impacts are a key consideration when planning major road infrastructure.

Baseline noise monitoring and modelling is currently being undertaken which, combined with other factors such as proposed design levels, road surface type and predicted traffic volumes will identify the forecast noise levels at sensitive noise receivers in the vicinity of the project. Where acceptable thresholds are exceeded, this will guide mitigation options in accordance with State Planning Policy 5.4 “Road and Rail Transport Noise and Freight Considerations in Land Use Planning”.

Should physical mitigation requirements be identified (e.g. noise walls adjacent to properties) as part of the detailed design process, property owners will be consulted.

 Why is the project needed?

• Reid Highway is a key east-west arterial road in Perth’s northern suburbs, linking two major north-south corridors: Mitchell Freeway to the west and Tonkin Highway to the east, and supporting efficient connectivity to Perth Airport.
• The intersection carries approximately 83,000 vehicles per day and was ranked the most congested intersection in WA in 2023/24. It also recorded the highest number of reported crashes in the Perth metropolitan area.
• We need to improve safety and traffic flows at this intersection given the crashes and delays experienced, which impact all road users, residents, public transport, freight traffic and businesses.
• Recent investments have focused on upgrading Reid Highway by progressively replacing at-grade signalised intersections with interchanges that enable free-flowing traffic.
• The Reid Highway / Erindale Road intersection is the last remaining at-grade intersection between Mitchell Freeway and Tonkin Highway. It plays a vital role in the broader road network, facilitating access to residential suburbs such as Hamersley and Warwick, as well as the Balcatta light industrial area.  

 What are the key features of the project?

Key features include (subject to change as site investigations progress):

• Retention of all current traffic movements to and from Reid Highway and Erindale Road
• A bridge carrying Erindale Road over Reid Highway, with partial cloverleaf interchange loop ramps in the north-eastern and south-eastern quadrants (similar to Tonkin Highway/Guildford Road or Tonkin Highway/Albany Highway)
• A new free-flow southbound ramp to connect Reid Highway (westbound) to Mitchell Freeway (southbound).
• Upgrades to the Erindale Road and Balcatta Road signalised intersection to improve current and future traffic flows into the Balcatta industrial precinct.
• Review of the Reid Highway and Balcatta Road intersection as it relates to the Mitchell Freeway southbound on-ramp.
• Principal Shared Path (PSP) upgrades along Reid Highway including new underpasses and overpasses providing improved connections to the PSP on the eastern side of the Mitchell Freeway. 

 What stage is the project in?

The project is currently in the planning and development phase. This phase involves various design investigations, site assessments and traffic modelling to confirm scope and progressing the required statutory approvals to allow for construction to commence in 2028.  

 What is being reviewed at Reid/Balcatta to build the new southbound ramp?

The intersection of Reid Highway and Balcatta Road is being reviewed to understand the impacts of enabling a free-flow southbound on-ramp to Mitchell Freeway.   

 What is being planned for cyclists and pedestrians?  

Upgrades to the Principal Shared Path (PSP) along Reid Highway including new underpasses and overpasses providing improved connections to the PSP on the eastern side of the Mitchell Freeway.

 What will it mean to my daily journeys?

You will spend less time in traffic on Reid Highway and adjoining local roads, resulting in quicker, safer and more efficient travel times.

The project is expected to significantly improve the daily commutes for residents in Balcatta, Hamersley, Warwick, and other northern and eastern suburbs, by easing congestion and delivering safer, more efficient roads.  

 What are the benefits of the project?   

The project will:

• Improve safety at the intersection of Reid Highway and Erindale Road.
• Reduce congestion and improve travel times along both Reid Highway and Erindale Road due to Reid travelling under Erindale.
• Improve freight travel time reliability and productivity, particularly access to and from the Balcatta industrial area.
• Improve accessibility and connectivity between Reid Highway, Mitchell Freeway, and Erindale Road.
• Upgrade the Principal Shared Path network, improving safety and connectivity for active transport users including, pedestrians and cyclists. 

 Who is funding the project?   

The $450 million project is jointly funded (50% each) by the State and Federal Governments.  

 What would happen to the network if the project was not built?  

Traffic is increasing each year, so if the project was not built:

• Congestion and serious (high severity) crashes would increase.
• Travel times for all road users would continue to increase.
• Travel efficiency would continue to decline for businesses in the Balcatta Industrial Area.
• Reliability of public transport would be impacted with increased travel time for PTA bus services to/from Warwick Rail Station.
• Active transport facilities—such as pedestrian and cyclist crossing points—would remain at grade. This would place additional pressure on an already congested road network, while safety outcomes for active transport users would remain unchanged. 

 Will you improve the surrounding areas?

Vehicles avoid congested areas and seek alternative routes, including local roads, which impacts the amenity of the surrounding area.

Safer and faster access to the road network and the Balcatta Industrial area will ensure regional travel users are on regional roads rather than local roads.

People walking and cycling will have new and improved shared path infrastructure to encourage active transport as a safe and viable alternative travel mode with effective north south and east west links.

Importantly, development of a Project Urban Design Framework, with the City of Stirling, is underway to guide the development of the project and ensure it retains a sense of place for the local community.  

 How will the environment be impacted?

During project development work, environmental assessments will be undertaken to inform environmental processes and approvals.

Main Roads is committed to reducing environmental impacts during planning, construction, and maintenance of road projects. We are undertaking studies and field assessments to understand environmental values within the proposed project extent to inform mitigation strategies.

The following State and Federal Environmental Approvals are required for the project:

• Federal: Referral to the Federal Department of Climate Change, Energy, the Environment and Water for assessment of preliminary documentation under the Environment Protection and Biodiversity Conservation (EPBC) Act.
• State: Referral to the Environmental Protection Authority (EPA) for assessment.

 Will Main Roads be acquiring land?

Some land acquisition may be required. We will meet with any potentially impacted landowners in coming months.  

 How can I have my say?  

The community can provide feedback at any time by contacting us on 138 138 or enquiries@mainroads.wa.gov.au. We will also seek your feedback online at My Say Transport (launching soon) to help inform design development.

 Will Reid Highway move closer to houses?

Yes, however, the highway lanes will remain within the available road reserve.  

 When will the project be built?

Planning and development work is expected to be complete in 2027/28.

Detailed design and construction are scheduled to commence in 2028 (subject to statutory approvals).  

 Will noise walls be built?

Baseline noise monitoring has been undertaken. Main Roads is guided by the Western Australian Planning Commission (WAPC) Road and Rail Transport Noise and Freight Considerations in Land Use Planning (State Planning Policy 5.4).

The noise monitoring will inform a noise mitigation strategy and indicate whether noise walls will be proposed in the vicinity of the project area. As the project design progresses and more data becomes available, noise modelling and proposed noise mitigation treatments will be reviewed and refined.

Further consultation with residents will occur at that time.

 Will my house face a high noise wall, and how high will the wall be?

The Project Urban Design Framework will assess high level visual impacts and guide future visual screening assessments and proposed wall/screen placements. Consultation with residents will then occur.  

 How will bus services be affected?

We are working with the Public Transport Authority (PTA) to discuss the project and understand bus movements through the area.

We are working with the City of Stirling and will determine if local school and community facility bus routes may be impacted.

Project Updates

• Project Update - March 2026 - PDF (691 KB)

Funding

Funding of $450 million has recently been committed to undertake the development and delivery of these works, with 50/50 funding from the State and Federal governments.