Works are now underway on a $150 million upgrade to the Mount Barker and Verdun interchanges, jointly funded by the Federal Government and South Australian Government.
The Federal Government is contributing $120 million and the South Australian Government providing $30 million.
Site preparations are underway at both locations, with night works commencing at Verdun from Sunday 22 February and at Mount Barker from 1 March.
Approximately 31,000 vehicles travel along the Freeway daily between the Mount Barker and Verdun interchanges, with 46,000 vehicles travelling from Verdun into the city. The Mount Barker interchange sees about 31,200 vehicles daily and has experienced significant congestion and queuing. Between 2019 and 2023, there were 43 crashes at Mount Barker and 11 at Verdun.
The upgraded interchanges will increase capacity, reduce bottlenecks and the risk of crashes, and better accommodate growth in the rapidly expanding Mount Barker and Adelaide Hills area. Improved traffic flow will also support emergency response times and make the interchanges easier for tourists to navigate.
Construction on the Mount Barker Interchange will include a new three-lane bridge across the South Eastern Freeway for northbound traffic and the conversion of the existing bridge to accommodate three lanes of southbound traffic. Installing the bridge will require 12 super-T girders, each weighing 85 tonnes, along with around 20,000 tonnes of asphalt and 500 metres of new underground pit and pipe drainage. New traffic signals, smart lighting, a shared use path for pedestrians and cyclists, and a priority bus lane will further improve safety and access.
At Verdun, the existing interchange will be upgraded to a full interchange, providing access to and from the South Eastern Freeway in all directions. This will address current limitations, such as the lack of an exit ramp for motorists travelling from Mount Barker to Hahndorf and missing eastbound entry ramps. The full interchange will feature a new eastbound entry ramp towards Mount Barker and a new westbound exit ramp connecting to a roundabout at Mount Barker Road and Silver Road. The new bridge over the westbound Freeway exit underpass will span 13.45 metres with a seven-metre deck, supported by 26 concrete piles and 12 bridge planks. Construction will include more than 20,000 tonnes of asphalt, 86 tonnes of concrete capping beams, over 13,000 tonnes of granular pavement, and 2.25 kilometres of new stormwater pipes.
The Mount Barker Interchange upgrade is being delivered by South Australian company, Bardavcol, while a joint venture between BMD Constructions and Leed Engineering and Construction will deliver the Verdun Interchange. The total project is expected to support around 260 full-time equivalent jobs per year during construction, with both interchanges scheduled to open to traffic in late 2027.
These projects complement the ongoing $40 million upgrade of the Mount Barker roundabout at the intersection of Adelaide Road, Alexandrina Road, Wellington Road and Flaxley Road.
