South Rd resurfacing works between Mile End South and Thebarton finished, St Marys and Black Forest next

South Rd is being smoothed out and resurfaced ahead of work on the tunnels below – but the cost of the project has hit $26m.

Resurfacing work along South Rd to prepare for tunnel boring works has increased by $4m after the need for additional repairs were identified.

The $22m project to resurface about 6km of South Rd to create a stronger road surface started in February.

But the cost has increased to $26m after the project’s scope was increased.

South Rd’s surface is being relaid to increase its long-term safety and strength before major works start on the twin tunnels in the $15.4bn River Torrens to Darlington Project.

A spokesperson for Transport Minister Tom Koutsantonis said the South Rd project cost increase was due to “additional scope being undertaken over and above what was initially identified”.

Extra repairs were needed for an extended area of South Rd at the northern and southern ends of the T2D alignment.

The upgrade now also includes extended treatments where South Rd intersects Cross Rd, while an additional 130m of Sir Donald Bradman Dr will be repaired for future James Congdon Drive intersection upgrades.

New median kerbing along South Rd will also be installed. All funding comes out of the overall T2D budget, they said.

Meanwhile, the next stage of resurfacing work along South Rd has been revealed, with stretches at St Marys and Black Forest in line for upgrades.

Resurfacing work on the northern section of South Rd has finished, creating a smoother ride between James Congdon Drive, Mile End South and Ashwin Parade, Thebarton.

The existing pavement on the 2.4km section of South Rd has been removed and replaced with new asphalt.

The tunnels – with a connecting open motorway – will stretch from Richmond to Torrensville and Clovelly Park to Glandore.

An artist impression showing the northern entry and exit points of the Southern Tunnels. The tunnels will surface at Glandore. Supplied: SA Government

About 631,000 recycled glass bottles and more than 3600 tonnes of recycled asphalt pavement were diverted from landfill and reused in the just-finished section around Thebarton.

Using sustainable asphalt saved the equivalent of approximately 127 tonnes of carbon dioxide, the equivalent of 58 cars off the road for one year.

More than 50,000 vehicles per day use the section of South Rd being resurfaced above where the T2D tunnels will be.

The area of South Road at Torrensville and Thebarton where the new tunnels will be built. Picture: Supplied

Resurfacing work between Bennet and Norrie avenues – including the resurfacing of the Daws Road intersection – is expected to be completed within weeks.

Once that’s finished, the remaining sections of works between Norrie and Rothesay avenues at St Marys and Glengarry Ave and Cowper Rd at Black Forest will start.

All resurfacing works should be finished by the end of the year.

Transport Minister Tom Koutsantonis said some sections of South Rd had reached the end of its life.

“The 2.4km northern section of works has been a massive undertaking, but has delivered a smoother and safer ride directly above where the northern tunnels will be,” he said.

“Sustainability has been a priority as part of these resurfacing works and the use of sustainably-sourced asphalt has helped lower the carbon footprint for the T2D Project.

“We have completed more than 6km of resurfacing on South Rd and there is still more to come, with some smaller sections on the southern side to be completed by the end of the year.”

Originally published as South Rd resurfacing works between Mile End South and Thebarton finished, St Marys and Black Forest next