Problem to be addressed
The Peak Downs Highway is used to transport essential mining inputs such as fuel, plant and equipment, construction material and explosives. As the main non-coal import/export gateway for the region, it is also used to transport a variety of freight including raw sugar and petroleum.
Within Walkerston, the Peak Downs Highway passes through the town centre, which includes schools, community facilities and shops, resulting in poor amenity for the local residents. This section of the highway has a number of intersections that are becoming congested and will lead to longer travel times for commercial vehicles passing through the town.
The Walkerston Bypass project includes a 10.4 km realignment of the Peak Downs Highway, from west of Walkerston to the Mackay Ring Road at Stockroute Road. In diverting traffic (including heavy and dangerous goods transport) away from Walkerston’s main street, the new bypass will increase freight capacity, provide more direct connectivity for large vehicles, increase flood resilience, improve freight efficiency, and provide safety and amenity benefits for the local residents of Walkerston. The project also creates an opportunity for urban expansion in the regional townships of Walkerston, Mirani and Ooralea under the Mackay, Isaac and Whitsunday Regional Plan (2012).
Economic, social and environmental value
The proponent’s business case states that the net present value (NPV) of the project is $67 million, with a benefit-cost ratio (BCR) of 1.5, using a 7% real discount rate at P90 capital costs.
The project has strong strategic merit and this is supported by the benefits of the project exceeding the costs. The claimed benefits may be slightly understated as there may be additional benefits from flood mitigation which had not been quantified. Infrastructure Australia is confident that the proponent’s delivery model is appropriate for this type of project.