Adelaide's Outer Ring Route capacity

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Adelaide's Outer Ring Route capacity

Congestion on roads around Adelaide CBD
Early-stage proposal (Stage 1)
Adelaide, SA
Smaller cities and regional centres
Efficient urban transport networks
Problem/Opportunity timeframe
Medium term (5-10 years)
Proposed By
SA Government
Date added to the IPL
26 February 2021
Adelaide Outer Ring Route Capacity


Segments of Adelaide’s Outer Ring Route, which surrounds inner‑Adelaide, are heavily congested in peak and non-peak periods.

This results in inefficient and less productive freight movements, reduced performance of the public transport system, longer travel times, and decreased safety for commuters and pedestrians.

Adelaide’s Outer Ring Route includes six corridors that operate as the key freight route connecting the South Eastern Freeway, the Port of Adelaide, the Adelaide Airport, and intermodal terminals in northern Adelaide.

The North–South Corridor section of the Ring Route lies to the west of Adelaide CBD. The Infrastructure Priority List separately includes a proposal for Adelaide North–South Corridor Upgrade (remaining sections).

In 2019, delays on the most congested sections of the Outer Ring Route increased travel times by more than 25%.

Cross-city traffic patterns, increasing land use densities and the location of schools create conflicts at several intersections along the route, and on arterial roads that feed into key locations, including the Adelaide CBD.

There are also roads that are constrained by property and heritage considerations that restrict expansion of the road corridor.

The 2019 Australian Infrastructure Audit found that urban travel patterns are becoming increasingly complex, driven by economic, social, demographic and technological changes. This creates a risk of growing divergence between the way our networks are planned and designed, and the needs of customers, as is the case for the Adelaide Outer Ring Route.


Potential options to address the proposal include:

  • making better use of the existing infrastructure, such as with technology to improve traffic management
  • improving or removing intersections
  • bus network improvements
  • targeted high productivity vehicle access improvements.

Next steps

Proponent to develop potential investment options (Stage 2 of Infrastructure Australia’s Assessment Framework).