Officer Road South is an existing unsealed two lane, two way undivided road with no access ramps to Princes Freeway at the intersection.

BG&E was engaged by Satterley Property Group to upgrade the existing Officer South Road into a divided urban arterial road (north of Princes Freeway) with access to the Freeway in the form of a half-diamond interchange.

The works involve roadworks, earthworks, street lighting, safety barriers, drainage improvements, new shared paths, traffic signals, civil structures, signage and line marking, and associated works.

Working collaboratively with Cardinia Shire Council, the Department of Transport, and Melbourne Water – BG&E developed an innovative road geometry and drainage solution that enabled the different catchment areas to be captured and discharged to different drainage strategies, depending on the requirements of different stakeholders.

The coordination of geometric and drainage designs was particularly challenging due to a number of site constraints

• The geometric design was constrained by very flat existing terrain, the need to achieve 5.4 metres of overhead clearance under the Princes Freeway overbridge, and geometric tie-in points both on Officer South Road and at the freeway ramps.
• The drainage design, on the other hand, was constrained by the presence of large Melbourne Water retention basins next to Officer South Road, very high flood levels within the basins, the need to keep the road and drainage outlets above these flood levels, and limited space for drainage structures.