Problem to be addressed
The Great Northern Highway (GNH) forms part of the National Land Transport Network and provides a strategic freight link between the Perth metropolitan area and Western Australia’s north-west. The GNH services Western Australia’s growing mining, agricultural and northern tourist industries, carrying a mix of passenger and freight traffic. However, triple road trains (53.5 metre trucks) travelling on the GNH are restricted from the section of the highway between Wubin (276 km north of Perth) and Muchea (50 km north of Perth). These restrictions are caused by road alignments and gradient conditions that are unsuitable for triple road trains.
The Bindoon Bypass would address this problem by enabling triple road trains to travel along the entire length of the corridor, thereby avoiding the need to stop and decouple at Wubin. The proposed project is 66 km long, including construction of 61.6 km of new highway and 4.4 km of improvements to the existing GNH.
Economic, social and environmental value
The proponent’s reported net present value (NPV) for the project is $462 million, with a benefit‑cost ratio (BCR) of 3.4 using a 7% real discount rate and P50 capital cost estimate. Infrastructure Australia has independently reviewed the business case and agrees with the proponent that the proposed project benefits would outweigh its costs.
To inform project delivery, the proponent undertook a high-level risk assessment and delivery strategy for the project. The risk identification, assessment and mitigation approach developed in the business case is appropriate, although it requires further detailing and updating as part of future project planning and development works