Western Australia's first 'duck and dive design' is providing road users greater access, less congestion, better traffic flow and a safer network.
The $259 million Armadale Road to North Lake Road Bridge project is the centrepiece of an unprecedented program to relieve congestion in Perth's southern suburbs. The program includes two freeway widening projects, the Murdoch Drive Connection to Kwinana Freeway and Roe Highway, the widening of Karel Avenue and the widening of Armadale Road.
The heavily constrained site was bounded by a residential suburb directly to the south, commercial businesses and a retail park to the north, one of Perth's biggest shopping complexes and mixeduse development to the west. In addition, the project interfaced directly with one of the busiest railway stations on the Perth network, the Kwinana Freeway and five other major infrastructure projects.
The constrained project location with multiple stakeholder impacts required an ambitious low-impact design, including the sinking of Armadale Road beneath the intersection of Solomon Road, with connectivity on the local road network retained through a ground-level roundabout. This 'duck and dive' configuration, the first of its kind in Western Australia, posed a series of design and constructability challenges, with issues in areas such as ground water, drainage, lighting, utility services, pedestrian access and construction while maintaining traffic and pedestrian access.
Once the concept was identified and proven, we sought input from the community, local businesses and road users through a multifaceted engagement campaign. This included a combination of traditional and contemporary engagement forms. The project was delivered on time and on budget between 2019 and 2021 by the Armadale Access Alliance, comprising of Main Roads, Laing O'Rourke and BG&E.
Upon opening to traffic in December 2021, the new road network has reduced congestion at the Kwinana Freeway, Armadale Road and Beeliar Drive interchange and improved local access to and from the suburbs of Atwell and Treeby, and around the major shopping precinct.
Over time, this will enable full implementation of the Cockburn Central Activity Centre Strategy and the City of Cockburn's strategic vision for the precinct, which were previously inhibited by severe congestion and poor access.