Detailed design of the $310 million upgrade commenced in January 2012 and construction is expected to start in the second half of 2012 with completion expected in the first half of 2015, weather permitting.

The upgrade will provide 7.5 kilometres of upgraded highway and include two new interchanges to Gerringong and Gerroa.

The upgrade will include:

• A new carriageway with a median barrier generally following the existing highway alignment.
• A posted 100 km/h speed limit over most of the upgrade.
• A new grade separated interchange at Rose Valley Road and a service road connecting to Fern Street.
• A new grade separated interchange at Belinda Street with a service road connecting to Willowvale Road.
• A new grade separated interchange at Rose Valley Road and service road connecting to Fern Street.
• A third lane for slow vehicles from Rose Valley Road to Mount Pleasant.
• A new overbridge replacing the railway level crossing in Fern Street.
• Improving highway flood immunity to accommodate a one in 100 year flood event.
• Preserving the largest Moreton Bay fig tree at the Rose Valley interchange.
• Four new shared access roads connecting to the Gerringong upgrade at Rose Valley Road, a northern shared access road combining three existing accesses, Sims Road, and a southern shared access road (north of The Pottery).

Background

In June 2009 Roads and Maritime Services announced a preferred option for the upgrade of the Princes Highway between Gerringong and Bomaderry. Roads and Maritime Services is now planning the works as three separate projects:

• Gerringong upgrade (Mount Pleasant to Toolijooa Road).
• Foxground and Berry bypass (Toolijooa Road to Schofields Lane).
• Berry to Bomaderry bypass (Schofields Lane to Cambewarra Road).

The preferred concept design was described and environmental, social and functional constraints outlined in the Gerringong to Bomaderry Princes Highway Upgrade Preferred Option Report, Roads and Maritime Services October 2008. This can be accessed from the project documents page.

In 2011, Roads and Maritime Services developed and selected designs for three new shared access roads connecting to the Gerringong Upgrade. These designs were adopted following feedback from property owners in late 2011. Concepts for shared access roads at Rose Valley Road, Sims Road and a southern shared access road (north of The Pottery) is now in the final design and construction.

Key benefits of the upgrade

• Improving safety and traffic efficiency at Fern Street and Belinda Street.
• Improving safety by removing the rail level crossing at Fern Street.
• Providing access to Gerringong via the new Belinda Street interchange that is protected from flooding to the level of a one in 100 year rainfall event.
• Improving safety at local road accesses such as Willowvale Road, Sims Road and Rose Valley Road.
• Improving safety and traffic efficiency through the additional (third) lane climbing to Mount Pleasant.
• Improving safety at property accesses.
• Providing safe crossing at the highway by cattle and farm machinery through underpasses.

Environmental impact assessment

Roads and Maritime Services prepared an environmental impact assessment, called a review of environmental factors, to examine the potential impacts and propose safeguards and ameliorative actions for the project. This assessment was displayed for comment in mid 2010 and 72 submissions were received. A copy of the review of environmental factors and submissions report can be found in the project documents page.