Karrara Bridge and Princes Highway

Scope of works

The works included:

• The construction of a new 48m long, twin-span bridge.
• The construction of a four-lane, 1.2km extension of Fowlers Road to Fairwater Drive.
• The construction of a parallel shared pathway for cyclists and pedestrians.
• Bulk and detailed earthworks, including stabilisation of embankment, flood cut and channel excavation.
• A new, 235m long road bridge over Mullet Creek and the Illawarra rail corridor.
• Relocation of 33kV aerial feeder and 11kV underground cabling within the rail corridor.
• New access track for maintenance or relocated assets in the rail corridor.
• Reconfiguration of the intersection of the new road with Princes Highway.
• Marshall Street deviation works.
• Utility adjustments.
• Street lighting.
• New traffic signals installed at the intersection of Daisy Bank and Fairwater Drive, with existing signals updated to suit new road widening at the Princes Highway and Fowlers Road intersection.
• Drainage
• Road marking and signage
• Landscaping.
•  2.6km new twin carriageway road with connections to existing intersections and widening of the Princess Highway. 
• Two new ITS signalised intersections and roundabout modifications.
• 2 new bridges: 
  1. Small bridge of approximately 36 metres over the floodplain
  2. Main bridge of approximately 198 metres over Mullet Creek and railway line.

Extensive planning and innovation 

The construction works for the Karrara Bridge and upgrades to the Princes Highway were highly complex. A staged construction approach, with extensive planning, innovative thinking and flexibility helped to ensure the works were delivered successfully and ahead of schedule. The timely execution of rail shutdowns, electrical outages, and water cutovers along with our adaptable approach to staging traffic and managing pavement designs were critical to the success of the program.

To maintain a continuous flow of material, from excavation to treatment to pavement placement large volumes of site-won material including recycled asphalt pavement and lime were blended to make excavated soil suitable for conforming pavement. The process was carefully managed. At several locations, excavations exposed contaminated waste, requiring prompt implementation of procedures for testing, safe handling, and disposal.

Works within the live rail corridor were carried out while normal rail traffic continued, uninterrupted. Strict compliance with rail safe working procedures was essential.

Areas of ecologically significant vegetation were identified and protected to avoid disturbance, in accordance with a native vegetation Ecological Constraint Assessment.  Areas of Aboriginal significance were identified and managed through an Aboriginal Heritage Impact Permit (AHIP). 

Working close to school zones restricted material haulage during school hours. The frequency of vehicle movements through school zones was limited, and alternate, longer routes were used by most haulage vehicles during these periods. 

Works at the new intersection of the Fowlers Road extension and the Princes Highway required reconfiguration of lanes and widening over some sections. Works were carefully staged to minimise the need for lane closures on the highway and to avoid works during heavy traffic times. Lot adjustments were also required for some properties along the Princes Highway, which required sensitive handling of liaison with individual residents and business operators.

Improved infrastructure for the growing population

The Fowlers Road to Fairwater Drive Link, part of the West Dapto Access program was completed ahead of schedule and within budget. The new Karrara Bridge provides flood-resilient access to West Dapto, connecting it to the Dapto Town Centre, the Princes Highway, and the M1 Princes motorway, and accommodates future growth. Each day, the Karrara Bridge is used by thousands of road users, pedestrians, and cyclists. The project is the largest ever undertaken by the council and was part of their ongoing investment in helping future growth in the Illawarra region. The bridge has been aptly named Karrara Bridge after the traditional Aboriginal name for Upper Mullet Creek, following a community vote, in tribute to the traditional owners of the land. The project has received multiple awards and exceeded targets in Indigenous participation.