Elon Musk does the math on another massive tunnel

Could yet another Elon Musk project in Australia have blossomed on Twitter?

Probably not, but he's quoted $1 billion AUD for it anyway.

The Tesla CEO responded to a tweet from Australian politician Jeremy Buckingham, who reached out to Musk about solving traffic congestion in Sydney with a tunnel possibly similar to the test unveiled by The Boring Company in Los Angeles.

Currently home to several multi-billion-dollar tunnel projects, Sydney is Australia's most congested city, according to a 2018 report by the National Roads and Motorists' Association (NRMA).

Buckingham, a Sydney-based, independent New South Wales MP, wondered how much it would cost to build a 50-kilometer (31-mile) tunnel stretching through the Blue Mountains west of Sydney.

Musk responded, breaking down costs for two-way high speed transit at around $750 million (at $15 million per kilometer), and $50 million to build a station. If these numbers are in U.S dollars, that total $800 million translates to a cheeky A$1.1 billion.

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To put it in perspective, The Boring Company said its 1.14-mile (1.8 kilometer) test tunnel, located in Hawthorne, California, cost $10 million (A$13.8 miilion).

Buckingham added more detail, posting an image of the tunnel's potential route running from the suburb of Penrith in western Sydney to near Lithgow in the Blue Mountains, and writing that he'd raise the project with NSW Premier Gladys Berejiklian.

"Thanks mate. Sounds like a bargain," he replied.

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Predictably, and even though it was just a rough quote on Twitter, engineers and Australian politicians have already picked apart Musk's numbers.

NSW Transport Minister Andrew Constance had his team cost out the project, and declared it would more likely sit at A$3 billion for a road tunnel, or A$6 billion for a road and rail tunnel, reports the Australian Broadcasting Corporation (ABC).

"I absolutely love his vision," Constance told the broadcaster. "That's [the] kind of innovation in years to come which could form part of the transport network.

"If there's any unsolicited proposals we will absolutely take it very seriously, but at the moment what is being looked at from his perspective isn't a reality at this time."

Tunnel engineer Arnold Dix, advisor to fellow billionaire Richard Branson's Hyperloop project, told the ABC it was probably just a "thought bubble" from Musk, and that "he was probably just sitting on his jet with nothing to do."

"He's managed to popularize concepts and extreme engineering that no one was talking about previously," Dix told the broadcaster.

"On that note, I say it's not necessarily a bad thing. And if he's prepared to sign up to $1 billion price tag — like he did with the South Australian battery project — then I say sign him up."

It wouldn't be the first time Australian politicians have approached Musk on Twitter with an ambitious project.

In November 2018, Tesla CEO finished the world's biggest battery, a Powerpack system with 100 megawatts of capacity, in South Australia following a now famous bet derived from light Tesla bragging and Twitter banter with March 2018.

Musk said that if he didn't get it done in 100 days, he'd foot the bill, which could have been up to US$50 million (A$65 million). Yeah, he got it done.

Whether this tunnel happens is another thing, but if nothing else, the idea at least has this frustrated, traffic-logged Sydneysider thinking big.