Problem to be addressed
Adelaide’s 78 km North–South Corridor is a key freight and commuter route between Gawler in the north and Old Noarlunga in the south. As part of the National Land Transport Network, it facilitates freight movements to and from Adelaide Airport, the Port of Adelaide and surrounding industrial areas.
There is an overall program to upgrade the North–South Corridor, which is separately listed on the Infrastructure Priority List. By 2019, there will be a continuous motorway between Gawler and the River Torrens (5 km west of Adelaide CBD), except for the South Road section between Regency Road and Pym Street.
Traffic demand from growing population and employment centres in the north and south will exacerbate slow travel speeds and delays at signalised intersections along the route. The 2015 Australian Infrastructure Audit estimated that, without further investment, delays on the South Road corridor will cost $164 million in 2031 (2011 prices).
The project would upgrade 1.8 km of South Road to a three-lane (each way) motorway, connecting to the completed South Road Superway (that is, between Port River Expressway and Regency Road on the North–South Motorway) and the Torrens Road to River Torrens Project (currently under construction). It includes a motorway overpass of Regency Road, and an east–west overpass bridge for pedestrians and cyclists at Pym Street. It also includes the implementation of Intelligent Transport Systems.
Economic, social and environmental value
The vast majority of benefits from the project are travel-time savings for road users, with average savings of 2.5 minutes during peak periods on South Road between Regency Road and Pym Street.
The proponent’s stated benefit cost ratio is 3.6, with a net present value of $624 million (7% real discount rate).
Capital cost of initiative as stated by proponent (2017 business case) $354.3 million (P90, nominal, undiscounted) | Australian Government contribution $283.5 million | State government contribution $70.8 million | Private sector contribution N/A