Darlington interchange traffic delays to return amid $7m fix

Traffic restrictions are back at the $620m Darlington interchange as new work is undertaken to fix another retaining wall in danger of collapsing.

Motorists using the $620m Darlington interchange face new delays as urgent work is undertaken to fix one of its main retaining walls.

Frequent heavy rain throughout 2022 is believed to have destabilised a section on the western side of the lowered motorway between the Sturt Rd bridge and Flinders Dve.

Speed and lane restrictions already have been implemented ahead of remediation works similar to those required when other walls collapsed during construction of the interchange in 2019.

The contractor responsible for the project, Gateway South, has been unable to obtain certification for some sections of the interchange, leading to a protracted dispute with the Infrastructure and Transport Department.

The two sections of the collapsed revetment wall at the Darlington project in 2019. Picture: David Mariuz

Monitoring and site investigations recently detected new movement in the western walls, leading to a decision to spend $7m on fixing them.

Work will start on Monday, forcing the closure of two lanes on the western side and restrictions to the right turn lanes from Main South Rd into Sturt Rd for at least two months.

Infrastructure Minister Tom Koutsantonis said motorists were advised to take extra care when travelling in the area, allow extra time and observe signage and instructions of traffic management staff.

“We have already seen what can happen if the design flaw that led to the 2019 collapse of the concrete retaining walls on the eastern side is not properly dealt with,” he said.

“We apologise to road users for the inconvenience – but it is beyond time this project is brought to completion.”

Construction work underway on the Darlington interchange.

Mr Koutsantonis said the previous Liberal government should have ensured the walls were fixed before the interchange was opened.

“It was gross negligence and mismanagement by the former Liberal government not to insist both embankments were remediated simultaneously back in 2019 when the original fault was identified and while the project was still in its construction phase, so the works would not have impacted on commuters,” he said.

Mr Koutsantonis said the recent testing and monitoring “shows why a permanent solution needs to be undertaken immediately”

A Liberal spokesman rejected claims it was responsible for the ongoing problems with the interchange, saying Mr Koutsantonis had “kicked an own goal”.

“This debacle started under the former Labor Government in 2016 when they failed to identify existing SA Water pipes before starting the project,” he said.