Third lane added to South Rd tunnels, blowing out cost by $1bn, Hove level crossing upgrade scrapped

A third lane will be added to the final North-South Corridor section, blowing out the cost by $1bn, and the Hove level crossing has been scrapped.

The price tag for the final section of the North-South Corridor project has blown out by $1 billion in order to add third lanes in the tunnels, state budget papers reveal.

The state government has also bowed to community pressure and scrapped the controversial Hove level crossing upgrade.

Meanwhile, the government has unveiled the final costings of its inner-city sports and entertainment arena – the project will come in at $662.3 million, but this will be offset by the sale of the Adelaide Entertainment Centre.

No money has been allocated towards the development this year but $79 million has been committed to the arena over the subsequent three years.

Budget papers released on Tuesday show the last part of the North-South Corridor project – the Torrens to Darlington section – will now cost an estimated $9.9 billion, up from $8.9 billion in the 2020/21 budget, handed down in November.

Treasurer Rob Lucas said the price hike reflected an updated road layout, which included wider tunnels to allow three traffic lanes.

“The big reason for the difference is the (transport) department and the advisers have updated the traffic volume modelling and as a result of that …, in terms of future-proofing the tunnel they have said you’d be crazy not to actually ensure you have three lanes going both ways with sufficient shoulder capacity for emergencies as well,” he said.

Where the Torrens to Darlington tunnels will go. Picture: Supplied SA GOV

“Their argument was with the traffic modelling that they’ve got, if at some stage in the future you get to the stage of saying ‘why didn’t you actually have wider tunnels when you were advised’ it’s a bit late then to be digging everything up again and providing a wider tunnel.”

The final costings of the biggest infrastructure project in SA’s history, which will be delivered in two stages, will be completed once the business case for the project is finalised later this year.

Stage one involves the construction of a motorway from Darlington to Anzac Highway, including a 4km tunnel.

Major building work on the tunnel is due to start in late 2023.

The second stage will involve motorways from the Gallipoli Underpass to Sir Donald Bradman Drive and from West Thebarton Rd to the Torrens to Torrens section of the project.

A 4km tunnel is also included in the stage.

Once completed, the upgrade will create a 78km non-stop motorway from Gawler to Old Noarlunga, allowing drivers to bypass 21 sets of traffic lights and saving 24 minutes in travel time.

Mr Lucas also announced the Hove level crossing upgrade had been axed.

He said the decision was made in response to “significant local opposition” to the project, price increases and the federal government’s unwillingness to stump up more cash for the initiative.

Mr Lucas said the project’s initial price tag was $170 million and then it increased to either $290 million or $450 million, depending on which design option the government chose.

“The Commonwealth government in our discussions indicated they were unwilling to fund a $450 million project, and that’s not an unreasonable position to adopt,” he said.

“Given that, and given the significant local opposition, the government’s taken the decision to say it is no more – there will be no Hove level crossing (upgrade).”

The funding that had been earmarked for the project would now go towards other transport or road projects over the next four years.

The project aimed to remove the Hove level crossing by either building a rail overpass, at a cost of $290 million, or a rail underpass at a cost of $450 million.

Local residents had been campaigning against the “rail over” option, saying such a bridge would be an eyesore.

The government has also announced it will develop a program to identify and triage level crossing removal projects across SA over the next 10 years.

It will also investigate “congestion busting solutions” along Brighton Rd to reduce travel times and improve safety in the area.

Further details about the government’s pledged Riverbank Arena were also revealed in the budget papers.

The project, which had originally been touted as costing $700 million, is now expected to cost $662.3 million, and is due for completion in 2027.

However, Mr Lucas said the net cost would be “some tens of millions (of dollars)” less because it will be offset by the sale of the Adelaide Entertainment Centre.

No cash will be spent on the project in 2021/22 while $10 million, $20 million and $49 million has been committed in the following three years, respectively.

This money will finalise the planning for the project and fund early site works, including for the construction of a tunnel under Morphett St.

An artist impression of the proposed Riverbank Area to be built immediately west of the Morphett Street Bridge in the CBD. Picture: Supplied

Premier Steven Marshall said major construction was set to begin in 2025/26.

“We will transform what is currently under-utilised land next to Morphett Street Bridge into a 15,000-person, multipurpose arena, which will be a world-class event and entertainment space for large concerts, a new home for basketball, netball and tennis in the heart of the city, and an increased exhibition space to attract larger conventions,” he said.

The Advertiser revealed in March that the centrepiece of the Liberal government’s re-election bid was a $700 million arena, to be built between Adelaide’s railyards and the River Torrens.

It would be capable of hosting basketball, netball and tennis games, as well as concerts, and would replace the Adelaide Entertainment Centre.

Adelaide Venue Management Corporation CEO Anthony Kirchner told a parliamentary committee hearing on Monday the arena would pull in “in excess of $100 million in revenue each year” and cost “in the order of $80 million” a year.

However, on Tuesday, Mr Marshall corrected the record, telling parliament the arena would rake in $49.2 million annually and cost $34.5 million per year.

Meanwhile, the government will spend $17.9 billion over four years on infrastructure.

A a total of $8.8 billion of this will be put towards roads and public transport projects, including:

■ a bypass of Truro township and upgrade Accommodation Hill on the Sturt Highway;

■ an upgrade of the APY Lands Main Access Rd;

■ the next stage of the duplication of the Augusta Highway from near Nantawarra to Lochiel.

A total of $10 million will also go towards a business case for a Greater Adelaide freight bypass.

The bypass would divert trucks from the South Eastern Freeway and Cross Rd on to the North-South Freight Route via the Sturt Highway.

Originally published as Third lane added to South Rd tunnels, blowing out cost by $1bn, Hove level crossing upgrade scrapped