Why is the project needed?
Tonkin Highway is a major north–south corridor used by commuters, freight operators and local traffic. The existing signalised intersections at Hale Road, Welshpool Road East and Kelvin Road create delays and safety risks where highway traffic interacts with local road movements.
Between January 2020 and December 2024, the three intersections recorded 368 crashes, including 8 crashes that resulted in hospitalisation. Upgrading these intersections will improve safety and reduce congestion by removing signalised intersections and separating highway traffic from local road movements.
What will the project mean for my daily journey?
Removing the signalised intersections will allow traffic on Tonkin Highway to travel without stopping for cross traffic, improving travel time reliability across the surrounding road network. Traffic modelling indicates:
- time savings of up to four minutes travelling to Tonkin Highway from nearby residential areas
- time savings of up to three minutes travelling from Tonkin Highway to residential areas
- average travel time savings of up to five minutes across the surrounding road network.
Cyclists and pedestrians will also benefit from a new shared path along Tonkin Highway.
Why are south-facing ramps not included at Hale Road?
South-facing ramps were investigated during project planning. Detailed investigations identified significant impacts associated with these ramps including property acquisition, impacts to Hartfield Park and surrounding conservation areas, impacts to Welshpool Reserve and relocation of major infrastructure services.
The approved design includes north-facing ramps at Hale Road while avoiding these broader impacts. Drivers wishing to travel southbound will be able to access Tonkin Highway via the Welshpool Road East interchange.
Will the road move closer to houses?
In some areas the upgraded highway will move closer to nearby properties to accommodate the new ramps and road alignment. Where required, noise mitigation measures will be considered in accordance with State Planning Policy 5.4.
Will vegetation be cleared?
Some vegetation clearing is required to construct the interchanges, widen the highway and relocate utilities. All clearing will occur within the approved project footprint and in accordance with environmental approval conditions.
Will noise walls be built?
Noise modelling will be undertaken during detailed design in accordance with State Planning Policy 5.4. Where required under the policy, noise mitigation measures such as noise walls will be incorporated into the project.
Will the project increase traffic on local roads?
Upgrading Tonkin Highway to a freeway standard removes delays at the intersections and improves traffic flow along the corridor. Traffic modelling indicates that most drivers will remain on Tonkin Highway once these delays are removed, reducing the need to use local roads to avoid congestion. Main Roads will continue working with the City of Kalamunda to monitor local road conditions as the project progresses.
Will trucks continue using local streets such as Crystal Brook Road?
Heavy vehicles currently use some local roads to avoid delays at the existing signalised intersections. Upgrading the Welshpool Road East and Kelvin Road intersections will improve capacity and traffic flow, which is expected to reduce the need for trucks to seek alternative routes through local streets.
Is the Kelvin Road interchange still planned?
Yes. The Kelvin Road interchange remains part of the broader Tonkin Highway Corridor planning. Environmental approvals for this stage are progressing, and it will be delivered as a future stage subject to approvals and funding.
When will construction begin?
Following contract award the project will progress through detailed design and planning activities. Construction of the Hale Road and Welshpool Road East stage is anticipated to begin in late-2026 and is expected to take approximately two years to complete.
