Parsons Brinckerhoff Role: Design
The original Tullamarine-Calder Interchange had great potential for traffic accidents, because of the confluence of two major urban freeways and the need to traverse several lanes of traffic to reach the Bulla Road exit ramp. A major reconstruction project was undertaken to create a reconfigured and grade-separated interchange. Both the Tullamarine and Calder freeways were realigned, and entrance and exit ramps for Bulla Road were reconstructed. The project was the first road infrastructure project in Victoria to be delivered under a project alliance agreement, in which risks and rewards are shared by the project team. Parsons Brinckerhoff contributed multidisciplinary engineering services to the alliance.
Sustainability was an integral part of the design approach. In place of concrete pipes on the shoulder drainage system, the team used 100 percent recycled high-density polyethylene pipe. The pipe was made from plastic milk bottles generated from household recycling programs, and was easier and safer to install. The team also incorporated 210 solar panels into freeway noise walls, offsetting up to 10 percent of the annual interchange lighting power demand, and reducing carbon dioxide emissions by an estimated 26 tons per year. The storm water bioretention system provides storm water quality treatment for site runoff.
The Tullamarine-Calder Interchange project was completed in 2007; it was delivered five months ahead of schedule, and nearly 10 percent under budget. In 2008, the improved interchange handled 25 percent more traffic at rush hour than the original interchange, with minimal congestion and an improved safety record.