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Frequently Asked Questions

What is the southern expressway duplication?

The Southern Expressway Duplication project will transform the one-way reversible expressway into an 18.5 kilometre multi-lane, two-way expressway between Bedford Park and Old Noarlunga.

The new carriageway will be constructed on the western side of the existing roadway and will give northbound traffic two lanes from Old Noarlunga to Reynella and four lanes from Reynella to Bedford Park. 

The existing carriageway will be used by southbound traffic with three lanes from Bedford Park to Reynella and two lanes from Reynella to Old Noarlunga.

When will the project be finished?

Opening the Southern Expressway to two-way traffic is scheduled to occur in late July/early August 2014 – subject to weather conditions.

Prior to this occurring an intense series of inter-connected work activities will be required over the winter school holidays (whilst traffic volumes are lower) including asphalt works to link existing and new infrastructure, traffic signal changes, line marking at interchanges, decommissioning of the current one-way electronic signage system and preparation for activation of the two-way system.

Some activities such as two-way electronic signage system activation and landscaping will continue following opening of the two-way expressway to traffic. This will required some inter-peak and weekend closures and lane restrictions. Peak traffic movements will not be affected.

Speed restrictions will also remain in place on the new expressway carriageway for safety reasons due to the use of Open Graded Asphalt which has low grip levels until the surface bitumen wears a little. The surface is being tested regularly, and as soon as it is safe to do so speed limits will be increased. 

How much will it cost?

The total cost of the project is $407.5 million. 

What are the benefits?

The benefits of a duplicated Southern Expressway are:

  • greater travel efficiency and better access for commercial traffic to industrial areas and facilities in Adelaide’s south
  • improved access for people living in Adelaide’s south to employment, education, recreation and community facilities both in the south and the wider metropolitan area
  • reduced travel times and ease of journey to tourist locations along the Fleurieu Peninsula
  • two-way travel 24 hours a day, seven days a week, the length of the Southern Expressway
  • support for southern region economic development
  • improved road safety for commuters
  • improved emergency service access thanks to simultaneous north and southbound travel on the Southern Expressway.

Who is paying for it?

The South Australian Government is funding the duplication of the Southern Expressway.

Who are the contractors for the construction?

The Baulderstone Abigroup Joint Venture (BAJV) has been awarded the Design and Construct contract for the Southern Expressway Duplication project.  Design and construction of the new carriageway is being undertaken concurrently. Construction commenced in early 2012.

The Baulderstone Abigroup Joint Venture is a fully integrated joint venture formed specifically to deliver the Southern Expressway Duplication project. Baulderstone and Abigroup are both construction companies with significant experience in the delivery of major infrastructure projects.

For more information about these two companies please visit and

Why wasn’t the road two-way when first constructed?

The Southern Expressway was originally constructed as a reversible road flowing in the peak direction to relieve congestion on Main South Road.

Was land acquisition required for the duplication?

No. The land being used to duplicate the expressway was purchased by the State Government during planning for the original expressway in preparation for duplication of the expressway at some time in the future. 

Expressway access and interchanges

Where can I access the Southern Expressway?

You will be able to enter and exit the expressway at all existing interchanges including:

  • Main South Road, Darlington
  • Marion Road, Sturt
  • Panalatinga Road / Main South Road, Reynella
  • Sherriffs Road, Reynella
  • Beach Road, Noarlunga
  • Main South Road, Old Noarlunga

During construction, these interchanges will remain open for access to the existing expressway in peak periods, however lane and speed restrictions will be in place.

You can view more information at Interchanges and Junctions.

Interchanges - what do they look like and how do they work?

There will be changes to the expressway interchanges to create on and off ramps for the two-way expressway. 

You can view more information about the design and functionality of interchanges at Interchanges and Junctions.

Will there be any additional access points?

All existing access to the expressway will be maintained at the completion of works with additional movements provided at the following locations:

  • left turn from Marion Road to travel southbound on the Southern Expressway
  • right turn from Southern Expressway (northbound) to Marion Road
  • formalised left turn from Southern Expressway (southbound) to Main South Road at Old Noarlunga.

Access to and from the south is predominantly serviced by three arterial roads - Main South Road, Southern Expressway and Ocean Boulevard / Lonsdale Road. The expressway caters for longer distance trips, leaving shorter more 'local' trips on the adjacent arterial road network.

The provision of additional access points along the Southern Expressway, such as southbound at Reynella interchange and Majors Road was considered during planning.  It was determined these would impact unnecessarily on expressway traffic flows, considering the traffic capacity available on parallel routes, such as Main South Road.

Further, given the high speed environment of an expressway, safety is a critical concern. Additional access points along the expressway introduce extra traffic weaving manoeuvres, which have consequential effects on traffic safety and efficiency.

Construction Works

How long will construction take?

The design and construction works are expected to take about two years to complete, with the duplicated expressway scheduled to open to two-way traffic in late July/early August 2014 – subject to weather conditions.

What is the status of the design?

Design and construction of the new carriageway is being undertaken concurrently, with the design being continually refined as the project progresses. Major landscaping, noise attenuation treatments, pathways and urban design features will be undertaken progressively throughout the works.

The project team will continue to engage with local residents, community groups and businesses on design issues that directly affect them throughout the project.

To view the expressway designs visit the design works section of the website.

Why are there reduced speed limits on the expressway?

Constructing a new road with complex construction works, within a narrow corridor and constantly changing traffic environment, while safely maintaining an operating road network has many challenges.

The current speed limits on the Southern Expressway have been implemented for the safety of all road users (road workers and motorists) and installed in accordance with Australian Standards and relevant guidelines, as required for construction works. The restrictions are necessary, regardless of the presence of workers, for several reasons including:

  • Reduced lane widths
  • Safety requirements whilst concrete barriers are under construction and temporary barriers are in place (resulting in reduced sight distances on curves)
  • Proximity of workers to traffic.

What measures will be taken to manage traffic conditions and keep road users informed?

Traffic will be carefully managed to minimise disruption for motorists while ensuring the project can progress on schedule. Motorists are advised to allow more time for travel while construction is underway, take care on the road and adhere to speed restrictions, which are in place for everyone’s safety.

Road users will be notified in advance of any major closures of the expressway or surrounding roads through the project website, traffic updates on local radio stations and local letterbox drops for bridge closures. 

Motorists are encouraged to subscribe for updates or to 'Follow DPTI' on Twitter or ’Like DPTI’ on Facebook for traffic and project updates. Please contact us for details on how to subscribe. 

If you need further information about traffic changes please visit the traffic restrictions page of the project website or contact the Southern Expressway Duplication project’s Information Line on 1300 626 097.

How is the community being engaged throughout the project?

Community engagement is a high priority for the department during planning, design and construction of the Southern Expressway Duplication.

The project team is working with community groups and local businesses affected by construction and will continue to engage with local residents and stakeholders on specific design elements throughout the project. 

Monthly updates are provided online, along with advance notice of construction activities for local residents, businesses, public transport commuters and road users.

For detailed information visit the community engagement page of the project website.

Environmental Management

What will be done to manage construction noise and dust for residents?

Every effort is being made to minimise the impact of construction, however local residents are advised that this project requires the use of heavy, specialised and often noisy equipment.  Noise impacts will be managed where possible using mitigation measures, such as turning engines and generators off instead of leaving them idle, minimising the need for night works and monitoring noise and modifying work activities where possible. 

Residents along the expressway will also notice an increase in truck and vehicle movements in the local area.  Trucks using local roads to move material from site to site will use defined routes along main roads and enter and exit the work site at established entry points.

In addition, access roads are being established within the existing expressway corridor to minimise the impact on the local road network.

During construction, dust will be managed in accordance with the Air Quality Management Plan and will include management measures such as:

  • dust monitoring
  • use of water carts to wet down soils, stockpiles and access roads
  • stop-work procedures during windy weather conditions
  • early installation of mulch and landscaping.

For more information about the practices in place, please visit the environmental management section of the website.

Will any work be done at night?

Some work may be carried out at night to reduce the impact of works on motorists and public transport users and to ensure works are undertaken as safely and quickly as possible.

Construction crews will generally work from Monday to Saturday between 7am and 7pm, weather permitting.

At times, it may be necessary for crews to work outside of these times. If this is the case and impacts to adjacent property owners are expected, advance notification will be provided.

How will traffic noise be managed?

Noise is recognised as a key environmental issue in constructing the Southern Expressway Duplication.  Noise modelling and assessments have been undertaken and mitigation treatment requirements identified where noise is expected to exceed the Road Traffic Noise Guidelines.

For further details visit the Noise Barriers page.

How will sensitive areas be managed?

The department has been engaging with special interest groups and other government departments to assist with management of sensitive environmental areas during the planning and design phase of the project including:

  • Environmental Protection Authority
  • Department of Environment, Water and Natural Resources
  • Adelaide Mount lofty Natural Resources Management Board
  • local government
  • Friends of Warriparinga
  • heritage groups
  • Living Kaurna Cultural Centre
  • Friends of Living Christie Creek
  • Friends of the Lower Field River
  • Trees For Life
  • other local stakeholders

The department will continue to engage with these groups throughout construction to ensure the works are carried out sensitive to these important areas.

Will the project impact the Remnant Vegetation at the Beach Road interchange?

The design of the new north bound off ramp at the Beach Road Interchange includes a retaining wall to minimise impacts to the remnant Grey Box woodland.  Tree protection measures will also be put in place during construction.

Local employment

How many locals has the project employed?

Please see the Employment page for information.

How do I find out more about the project?

For further information, provide your comments or to subscribe for updates please:

  • complete the online comments form
  • call 1300 626 097 and speak to a member of the project team
  • email the project team at
  • visit the site office, 3 Majors Road, O’Halloran Hill, SA 5158
  • post a letter to Southern Expressway Duplication, Department of Planning, Transport and Infrastructure, Reply Paid 1533, Adelaide SA 5001.

Project statistics

  • 7000 holes bored to accommodate blasting with up to 250 tonne of explosive product.
  • 1.6million m³ of cut to fill
  • 12 000 litres of diesel used every day and up to 20 000 litres at peak
  • 200 000 tonnes of asphalt will be used
  • 32 km of slip form barriers being installed on the live Expressway.
  • 8326 m³ of concrete.
  • 1403 tonnes of steel used in the bridge structures and retaining walls.