- Reducing traffic congestion and one of the state's worst bottlenecks
- Working in densley populated areas whilst keeping existing roads open
The Airport Link project includes three separate projects – the Northern Busway (a 3km two-way dedicated busway from Windsor to Kedron), the Airport Roundabout Upgrade and AirportlinkM7 (a 6.7km toll road including 5.2km of tunnel).
Together, the projects will reduce traffic congestion for the inner northern suburbs of Brisbane by 45%, fixing one of the state’s worst bottlenecks.
Scale and complexity
The scale and complexity of the project, along with very tight constraints imposed by a highly populated environment and the need to keep roads open, presented a formidable design challenge.
To meet this challenge, Arup joined forces with Parsons Brinckerhoff – as the PBA JV – to build a team that drew on extensive local and international skills and resources. Specialist design professionals were mobilised from around the world to form what became a highly effective delivery team. Over 1,000 PBA team members worked more than one million hours to design this project and provide construction phase support.
Design overcame multiple challenges
PBA’s solution essentially buried all the large, heavy traffic movements, leaving a surface solution for local movements to cater for buses, pedestrians and cyclists.
For Airport Link, the solution was achieved by changing the constructed road tunnel alignment given in the initial design brief. The design team removed the midpoint surface road junction and moved the road merges and diverges into underground caverns, reducing the surface impact of the project. In addition, two large tunnel ventilation buildings were either fully or partially buried underground, allowing parkland to be built over them.
The interchange design presented one of the biggest challenges for the design team. Traffic interchanges needed to be placed in the most densely populated parts of Brisbane, requiring intricate geometric solutions in very constrained areas. The solution incorporated four levels of traffic, including a fully grade-separated scheme which resulted in completely free-flowing carriageways with no traffic lights or stopping.
For the Airport Roundabout upgrade, the PBA team developed a solution that incorporates a fast-diamond interchange with two levels of overpass to replace the existing roundabout. The design includes a direct connection from the East West Arterial to Airport Drive with a 750m flyover, improving traffic flow significantly and providing excess capacity well beyond the contract’s nominated design.
The Northern Busway (Windsor to Kedron section) is a two-lane, two-way road for buses only, connecting the Royal Brisbane Hospital at Windsor to Kedron via the Lutwyche Road corridor. A challenge was the transformation of a section of Lutwyche Road into a bridge, enabling further construction on the Lutwyche Busway station.
Ground-breaking on so many levels, this project delivers an economic and social legacy for the broader Brisbane community. It has literally changed the maps, redefining the urban fabric of our city through an innovative and inspired design.