No additional properties will be destroyed for extra lanes in South Rd tunnel, minister says

The tunnels under South Rd will now have an extra lane each way and cost $1bn more – and the government has issued a fresh promise to landholders near the project.

No additional properties will be bulldozed to make way for the extra lanes planned for the Torrens to Darlington road project, the state government has promised.

In Tuesday’s budget, it was announced the underground tunnels planned for the final section of the North-South Corridor would have three lanes in each direction, instead of two.

It will cost an extra $1bn to add the lanes, taking the project’s projected bill to $9.9bn.

The tunnels will be widened by just 2m more than originally planned.

Transport Minister Corey Wingard said the changes would not lead to any more properties, beyond the original estimate of 390, being acquired by the government.

An artist impression of the latest version of the tunnels. The Torrens to Darlington section – which would include tunnels along South Rd – will now have three lanes each.

“The diameter of the circular cross-section that the tunnel-boring machine excavates will increase by approximately two metres to allow for the new design,” he said.

“The tunnels will be excavated at approximately 30m below the surface.”

Mr Wingard said it was “prudent and financially responsible” to expand the size of the tunnels because once built, they cannot be made bigger.

The Transport Department’s design involves two tunnels and a mix of surface and lowered motorways.

It would save 480 properties, which would have been demolished under an open-motorway option.

Under latest designs, the southern entry point would be just after Tonsley Blvd, with motorists exiting the tunnel near the Glenelg tramline.

Travelling north, motorists would enter a second tunnel just after Richmond Rd, with the off-ramp just before Grange Rd and Manton St. Mr Wingard said the final design would be completed later this year.

South Road Inner West Action Group member Mandy Doolan said it was hard to know exactly how many properties would be compulsory acquired until the design was finalised.

“Whether it’s three lanes going into or out of (the tunnels) I suppose is not the issue, it’s where the entry and exit points are going to be,” she said.

Ms Doolan said the community had been made aware prior to the budget that the government planned to widen the tunnels.

“We’re looking at this tunnel not for us, not for my generation,” she said.

“We are looking at this really for my children’s children. So, at the end of the day, we’ve got to make sure that the growth in the actual city is going to be enough to warrant three lanes.”

Treasurer Rob Lucas said the decision to widen the tunnels was based on revised traffic modelling.

Opposition transport spokesman Tom Koutsantonis said the government needed to be “completely transparent” with local property owners.

“People should know within days after this budget whether their house is needed or if it isn't,” he said.