Improving the road network for Phillip Island, Victoria’s most popular tourist destinations

Phillip Island is one of Victoria's premiere tourist destinations, attracting more than 1.8 million people each year and with a projection to reach 3.5 million people per year by 2035. The high visitor numbers have placed immense pressure on the island's road network, with tourists and residents finding it difficult to access and move around the island, especially during peak periods. Long-term planning for road network improvements was critical to the island's future.

Following DoT funding and the Phillip Island Integrated Transport Study (PIITS) in 2014, high priority was given to the intersection of Phillip Island Road. Supported by extensive data, these areas were known for high traffic volumes, long travel times and increased congestion.

Cardno was engaged by Regional Roads Victoria (RRV) to undertake the detailed design of the Phillip Island Road & Back Beach Road roundabout.

Cardno initially developed a functional design of the roundabout based on the concept designs prepared by RRV.

Following approval by authorities the design was then progressed to detailed design stage. 

Cardno conducted the ideal vertical alignment suitable for the project to balance earthwork volumes, plus provided pavement grading with appropriate cross falls, the design of adjacent shared use paths and drainage design.

The roundabout has improved access and safety for road users turning into and out of Back Beach Road, best known as the access point for the Penguin Parade, the Nobbies and the Grand Prix race track.

Cardno’s role and approach

The existing condition of the intersection resulted in flooding of adjacent properties during high rainfall. Our Geotechnical team conducted a flood modelling analysis to identify the impact of the new road construction on adjacent parcels of land, providing flooding mitigation recommendations for the project. Cardno proposed the construction of large swales along the northern length of Phillip Island Road to alleviate the flooding issue. We also recommended that the crossing drain transferring water from the north of the road to the south was down-sized in order to throttle the water. This approach allowed to reduce the flooding effects on both the northern and southern land parcels.

As it is was crucial not to disturb the existing cut batter, in collaboration with the RRV, both the horizontal and vertical design of the departure lane were tweaked making low-risk compromises to obtain a suitable design. This resulted in leaving the existing steep cut batter and the vegetation on the batter intact, providing privacy to the local residents.

Key benefits include:

  • Reduced congestion
  • Improved traffic flow
  • Safer journey for motorists