New Tatachilla overpass opens to traffic

Wednesday, 20 September 2023

The new Tatachilla overpass has opened to traffic, with the Main South Road and Victor Harbor Road duplication projects now more than 75 per cent completed.

The new overpass on Main South Road is located at the intersection of Tatachilla and Maslin Beach Roads. The northbound carriageway of the new overpass opened to traffic this morning with a single lane in each direction, improving traffic flow for the approximately 18,600 vehicles that use Main South Road every day, including more than 1000 heavy vehicles.

The overpass is supported by nine super-T girders. Each girder is 37.5 metres long and weighs 81.7 tonnes, or the equivalent of approximately 50 family sedans - the heaviest bridge beams that have been created in Adelaide for 15 years.

The girders were poured at Adelaide company Bianco, then trucked to the overpass site under special escort, before being craned into place.

The bridge span over Main South Road is 36 metres long with 180 cubic metres of concrete used to build the bridge deck. Almost 750 pre-cast wall panels, each weighing approximately two tonnes, also form part of the overpass.

The Tatachilla overpass is part of the stage one duplication of Main South Road. The duplication project includes the section of road between the intersection of Griffiths Drive and Robinson Road, and Port Road, Aldinga. Stage one is expected to be completed in early 2024.

The Australian and South Australian governments have committed a total of $685 million to fund the Main South Road and Victor Harbor Road Duplication projects.

So far, in total, 10 kilometres of road pavement has been laid; 55,500 tonnes of asphalt and 4,800 metres of drainage has been installed; 85 per cent of earthworks completed; and 8.5 kilometres of shared use path has been built.

When finished, these projects will result in safer and faster journeys for motorists and provide a vital boost for local tourism and communities. The projects are supporting hundreds of jobs each year during construction.