Darlington Upgrade Project
Darlington Upgrade project is part of the North-South Corridor, a critical route for the movement of freight and business-related passenger traffic. The successful delivery of the upgrade resulted in reduced travel times, improved freight transport productivity, reduced traffic congestion, improved safety and connectivity.

SMEC, alongside it’s joint venture partners, were engaged by the Department of Planning, Transport and Infrastructure as part of the Gateway South Consortium to design and construct the A$754.5 million Darlington Upgrade Project in Adelaide, Australia.


The Darlington Road Upgrade Project comprises the construction of 3km of free-flow motorway (with a maximum of five lanes in each direction), nine overbridges and at grade side surface roads. The project forms part of the Adelaide North-South Corridor Upgrade which is the centrepiece of South Australia’s transport infrastructure strategy.


It is arguably the most complex road project ever undertaken in South Australia with the upgrade taking place along the busiest road in the state within a heavily developed environment. Traffic makeup and volume combined with mixed residential, industrial, institutional and commercial land use along the corridor meant that the upgrade required clever and innovative engineering to deal with the complexity and constraints of such a dense brownfield environment.

of free-flow motorway construction
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Overcoming obstacles through strategic construction methodology

Together with its Joint Venture Partners, SMEC was responsible for design coordination, traffic modelling, geotechnical investigations, traffic engineering, bridge and road design, drainage and Intelligent Transportation System (ITS) design.

The SMEC team managed and successfully overcame many challenges, including the difficult geotechnical conditions which led to the use of unsaturated soil modelling and detailed traffic modelling in support of construction staging to ensure traffic flows at peak periods.


The interconnectivity of each section of the scheme was another challenge. At each stage, SMEC considered the impacts not only in the current stage but also future stages, as well as consider ramifications for construction methodology. SMEC’s knowledge of traffic movements on site and its understanding of minimum requirements were critical in ensuring that proposed staging plans were feasible and that any issues were detected early so that they could either be avoided or addressed.


Improved travel and connectivity

The project is part of the North-South Corridor, which is a critical route for the movement of freight and business-related passenger traffic, connecting the Port of Adelaide, Adelaide Airport, the Islington intermodal terminal and other freight terminals

The delievery of the Darlington Upgrade project resulted in the following benefits:

  • Reduced travel times for long distance north-south movements through Darlington
  • Reduced travel times for arterial road and local road movements
  • Improved freight transport productivity in Adelaide, enhanced productivity and increased competitiveness for export industries
  • Reduced traffic congestion and improved safety at this critical location and improved north-south traffic flows along the corridor

Improved connectivity for east-west traffic by reducing delays at South Road intersections.


Talk to one of our specialists about our role on Darlington Upgrade Project.