Florida politicians are eager to partner with Elon Musk’s Boring Company to build underground tunnels in order to relieve traffic.

Miami Mayor Francis Suarez tweeted with Musk about it on Jan. 18, and Suarez followed that up with a call with a Boring Company official. Last week, Fort Lauderdale Mayor Dean Trantalis announced that he, too, had spoken with leaders of The Boring Company, and Musk has said he has also been in touch with Florida Gov. Ron DeSantis.

Suarez told the Miami Herald he had only had preliminary talks about Miami projects. He said tunnels would cost $10M per mile.

In Fort Lauderdale, Trantalis was more specific. He said in a press conference last week that he had met with Boring Company officials about building a 3-mile tunnel under the New River and that it would cost $30M to $60M per mile, the Sun-Sentinel reported.

That figure was far less than the $1B per mile state transportation officials had estimated a tunnel would cost. They had proposed a $445M, 55-foot-high bridge instead.

“This is really a game-changer,” Trantalis said.

He deflected questions about where funds would come from.

The Boring Company has successfully built a test tunnel in Hawthorne, California, and began construction on a loop transportation system in Las Vegas. In Los Angeles, it has proposed a tunnel between Dodger Stadium and residential neighborhoods, and on the East Coast, it has proposed a system between Washington, D.C., and Baltimore.

South Florida is built upon limestone karst that is porous. Building tunnels requires sealing the structure and pumping out water as it is built. In 2014, a 4,200-foot tunnel was built connecting Port Miami to local highways, thus getting trucks off the road and alleviating traffic. It cost $668.5M.

Mika McKinnon, a Vancouver-based geophysicist, told Curbed that Miami’s limestone foundation is dissolvable and susceptible to collapse.

“I’d be asking them what their legal liability plan is,” McKinnon said. “Because part of the issue with the changing of the water table is that it won’t be a direct cause and effect — 30 blocks away is what is going to sink. This is not a feasible project without sinkholes, so what will they do when they get sued?”

McKinnon called Miami “a zombie city” and said that "buying coastal property in Miami is like throwing your money into the ocean.”

Local officials often acknowledge climate change but say they will meet the challenge, touting regional coordination and sustainability initiatives like $200M in bond money for mitigating the impact of sea-level rise and flood risks.