The $164 million Smithfield Bypass is a crucial infrastructure project for the northern beaches of Cairns, Far North Queensland. Removing through traffic from the local road network has significantly reduced congestion on the Captain Cook Highway between McGregor Road and Cairns Western Arterial Road. The bypass also improved access to nearby roads, like the Kennedy Highway, and eased traffic congestion at the Smithfield roundabout.

As part of a partnership with HDR, BG&E provided design management, bridge and staging design, and civil and traffic engineering services for the bypass. The Cairns Western Arterial Road was upgraded to four lanes from the southern connection of the bypass to the traffic signals at Caravonica State School. Traffic signals were also installed at Skyrail Drive to improve flow during peak times.

BG&E’s team identified an opportunity to develop an alternate layout to the original reference design. Rather than connecting at the Yorkeys Knob Intersection, the revised layout tied into the Cairns Western Arterial Road, drawing more traffic to this intersection and reducing congestion within Smithfield Township. This design change eliminated the need for millions of dollars in additional infrastructure that would have become obsolete within 10 years, delivering significant whole-of-life savings. The new layout earned an Excellent Design rating from the Infrastructure Sustainability Council of Australia.

The rapid changes in project scope posed challenges to the design process, but the team adopted a transparent and collaborative approach with the client. By delivering design work in a prioritised order, some construction phases could begin while the design was still ongoing, reducing overall project timeframes.

Opened in November 2021, the Smithfield Bypass addresses the area’s current and future needs, providing safer and more efficient travel for road users and supporting sustainable infrastructure development.