CityLink Tulla WideningCombating road network congestion to Melbourne Airport

Melbourne is continuing to grow at a rapid pace, with the population expected to rise to 7.7 million by 2051. With passengers travelling to Melbourne Airport expected to double by 2033, and freight handled by Melbourne ports to increase by 270 per cent by 2030, an additional 25,000 vehicles are expected to use the CityLink-Tullamarine freeway by this time.

To cater for this growth, and to combat an already heavily congested road network, the CityLink Tulla Widening project will ultimately increase the capacity of the road by 30 per cent by making significant improvements across 24 kilometres of the roadway from Melbourne Airport to Power Street. 

The project will see travel times reduced, and commuter safety improved through implementation of a managed motorway system and auto incident detection. 

In partnership with GHD, Aurecon and the team provided detailed design services for CPB on the upgrade of the Citylink, West Gate and Tullamarine freeway as part of Transurban's and VicRoads network.

Providing a range innovative solutions

The design joint venture (DJV) delivered a number of innovative solutions including:

• Use of steel barriers to allow drainage provisions to be reduced by allowing sheet flow under the steel barrier, which aided in design, construction and operational improvements.
• Changes to a collector distributor road and entry ramp to allow the removal of significant amounts of retaining walls to reduce traffic disruption during construction.
• Modifications to an existing bridge abutment through provision of a vertical abutment to prevent the need for a new bridge.
• Design methodology and risk approach that allowed flexibility on site due to inconsistent survey information, without impacting on traffic operations or construction activities.
• Design solution tailored to complete two week closure of a section of freeway for the demolition and reconstruction of an exit ramp using innovative precast concrete structures.
• Provision of civil, structural and electrical services to allow the installation of a state of the art managed motorway system in consultation with Transurban.

To ensure the roads remain operational throughout the project, significant input in relation to traffic staging arrangements has been made. Ultimately, innovative design has saved significant capital costs, minimised traffic disruptions during construction and aided in the overall construction methodology.