Is this Elon Musk's worst idea yet?

Elon Musk is finding ways to keep busy while he waits on the Twitter board to weigh his offer to buy the company. That includes espousing the virtues of tunnels as "immune to surface weather conditions," a thing which is very much not true.

On Sunday, Musk responded to a tweet from the World of Statistics account, as one does when they have $280 billion to their name and nothing else going on. That led to an exchange with CleanTechnica writer Johnna Crider about building a Hyperloop from Baton Rouge to New Orleans, which resulted in the following tweet:

There is perhaps no worse example of this than subways. Just last summer, New York's subway dealt with stations flooding multiple times, including during the remnants of Hurricane Ida, which shut down nearly the entire system. "That subway system is old and trash," you might say. You would be right — but also, show some respect.

It's also far from the only example of subway tunnels being decidedly not immune to surface weather conditions. In 2019, the Metro in Washington, D.C., sprung a leak following heavy rains. And last summer, Zhengzhou's metro — itself less than a decade old — faced deadly flooding following torrential rains.

Now, there's no denying the idea of speeding up evacuations from hurricane-prone areas would be a nice thing. But tunnels are a highly questionable way to make that happen, given the fact that — again — they flood. In South Louisiana, where sea level rise is a huge issue, the idea of building tunnels is even more sketchy.

But they're particularly dubious when we already have other policy tools at the ready. Equitable access to public transit, contraflow on highways and using traffic data to streamline the exodus when a storm is approaching are all right there for the taking. Are they as exciting as trains that don't yet exist zipping through vacuum-sealed tubes that don't yet exist? No, they are not. But they are proven methods to save lives.

Musk has had no shortage of pitching Hyperloop and tunneling projects that are highly suspect. That includes building tunnels in Fort Lauderdale, which sits in a part of Florida where the ground is essentially Swiss cheese. Anyway, Musk's Boring Company recently raised another $675 million to make traveling in Teslas in tunnels a growing thing in Vegas. And it tweeted on Monday that "Hyperloop testing at full-scale begins later this year." No word on whether it will take on the added challenge of doing that during a hurricane.

Correction: An earlier version of this story misspelled Johnna Crider's name. This story was updated on April 25, 2022.