Ask South Floridians about their cellars and you will likely get a confused look. There are few cellars or other underground structures in South Florida as the water table is only 3 to 8 feet below the land surface. Also, much of the state is built on reclaimed wetlands, the geology of which is mostly sand and karst or eroded limestone, which is porous, quite unstable, and prone to sinkholes. In connection with this, much of southeast Florida, less than 6 feet above sea level, is frequently flooded, even without storms. The floods are getting worse with climate change, as are the drenching storms like hurricanes.
Under these conditions, how feasible is The Boring Co.’s unsolicited proposal to build a subway transit project in Fort Lauderdale? Civil engineers and transportation experts say it’s doable despite the conditions, but there’s a catch: “This is doable, it just won’t get cheap,” said Norma Jean Mattei, professor of civil and environmental engineering at the University of New Orleans and past president the American Society of Civil Engineers.
Will it happen
The Boring Co. and the city had talks about building an underground alternative to it earlier this year a planned high-rise S-Bahn bridge over the New River, a canal that runs through the city. The company suggested building a three-mile stretch This would supposedly allow for faster and more efficient transportation between downtown Fort Lauderdale and the beach. Fort Lauderdale Mayor Dean Trantalis said on Twitter in July that the city had accepted Boring’s proposal and that competing firms had 45 days to submit their own proposals.
Fort Lauderdale officially has a proposal from tonight. accepted @elonmusk‘S @boringcompany to build an underground transport system between the city center and the beach. Other companies have 45 days to submit competing proposals. This could be a really innovative way to reduce traffic congestion. pic.twitter.com/R7Bh2NPVnl
– Mayor Dean J. Trantalis (@DeanTrantalis) July 6, 2021
The city publicly indicated that Boring Co. could continue to work on the Loop project – for example through geological studies – if no competitors bid. The city did not respond to requests for information about the current status of the offer or whether other companies had submitted offers.
This isn’t the first time developers have unveiled ambitious transit projects in Florida. Last year, Hyperloop Transportation Technologies proposed an ultra-high-speed Hyperloop from Tampa to South Florida, and Hyperloop One proposed a project from Orlando to Miami in 2017.
Underground loop projects are slow to develop, if they get off the ground at all. Skeptics point out that the only example that has materialized is the Boring Co. loop, which opened under the Las Vegas Convention Center in June. The project in Las Vegas is more modest than some of the plans that Boring Co. founder Elon Musk has described. Instead of, for example, much hyped Pods Driving through pressurized tubes at high speed, the vehicles in the Las Vegas Loop are Tesla autonomous cars that travel at speeds of up to 40 miles per hour through a single-car tunnel. P.However, proponents of innovation still point to its potential to disrupt traffic and reduce CO2 emissions.
The city was relatively calm about the potential project during the bidding process, but the city commissioner told Insider that the project is likely to cost $ 10-15 million per mile. With the suggested 3 miles, the minimum cost would be approximately $ 30 million.
Some skeptics estimate that the cost would end up being much higher. Florida state traffic officials estimated the price of a tunnel under the New River at more than $ 3 billion, so they proposed building a 55-foot bridge instead, at an estimated cost of $ 445 million.
In general, experts say, tunnels are costly to build due to construction, safety, and maintenance considerations.
“Tunneling is expensive. It is much more expensive than building above ground, “says Ruth Steiner. Professor of Urban and Regional Planning at the University of Florida.
Tunnels in a flood-prone area require even more work and money, Mattei said.
“When you think about the life cycle costs of a tunnel compared to a bridge, it becomes more expensive because you have to constantly drain and maintain the seal,” said Mattei.
“You can work your way out of any problem. It just takes money. “
Former senior transportation engineer with the California Department of Transportation
Experts say a Florida tunnel project would require extensive research and testing before developers could do it even think about building.
“They didn’t do a lot of tunneling in Florida so they really need to study the soil stratification and geology of the area,” Mattei said.
Water and flood research is also of crucial importance. South Florida’s tropical climate receives significant annual rainfall, as well as hurricanes and other heavy storms. In addition, the region is experiencing a tidal phenomenon called “King Tides,” where the rise in sea levels causes low-lying areas to be flooded with seawater at high tide even if no rain has fallen. All of these conditions worsen with climate change.
“You have to bypass all threats – and climate change is definitely one,” said Herby Lissade, a former school principal Transportation Engineer for the California Department of Transportation and past chairman of several committees of the Transportation Research Board. “She Hurricanes, storm surges and floods must be planned for. There’s no excuse not to plan it when you have all the data, “said Lissade, now eManaging Director at Tortuga Planning, Engineering and Consulting.
Severe floods sometimes flow into underground tunnels and transit stations. Superstorm Sandy, for example flooded New York subway stations in 2012, forcing the city to pump water out of the tunnels and make extensive repairs.
Surface flooding is not the only water problem for underground developments.
“There are also concerns about the disruption of groundwater flow and the possibility of subsidence,” Steiner said.
All things considered, a subway loop could probably be built in Fort Lauderdale, but it will likely take years of heavy engineering and funding.
“You can solve any problem yourself. It only costs money, ”said Lissade.
For whom is that?
Proponents are promoting the proposed Fort Lauderdale Loop as a form of transit. However, the focus on connecting a heavily commercial part of downtown to the beach suggests that it might serve tourists rather than residents.
Transportation experts say that every project should start with the question: who do we want to serve?
“Who are the people who use the service? How does it really live up to the goals that most cities pursue in terms of security, sustainability and equity? That should be the guiding light for projects like this “, said Zabe Bent, Director of Design at the National Association of City Transportation Officials, about major transportation projects in general. “WWhen we think of the many crises we are currently facing in terms of climate change, in terms of social justice, in terms of security and accessibility, we should think of projects that do more than one thing. “
Bent said Fort Lauderdale city planners might wonder if the tunnel would do more than just clear traffic jams, and if that is the best way to solve the problem. Transit is expensive to manufacture and it’s difficult to recoup the initial cost, Mattei said. The much appreciated initial project price and ongoing maintenance The cost could result in drivers having to pay a hefty fee to drive the ribbon, She said.
Steiner pointed out that innovative transit projects are even more expensive than traditional transit.
“NNew innovations find it difficult to distribute the costs among the consumption units. It’s basic economics, “Steiner said.” WWhen you do an innovation you have fixed costs at all stages of development, and the fewer units you buy, the more expensive it gets … The only way to cover this is to charge a lot. “
This raises concerns about the cheapness of which users the city should prioritize when launching projects, especially projects with innovative, largely unproven concepts that come at a higher price.
“We really have to think long and hard about whether we’re building the right project and placing it in the right place, and figuring out how everything fits together as a system. If it doesn’t serve the system, then we either have to repeat the project or think about a new one, “said Bent.” If so [underground loops] can be adopted … to serve as a transit for everyone, then I hope we see more of them. “
Until Fort Lauderdale officials announce the next steps, the subterranean loop proposal and its implications are only speculative for now.
“I have to give credit [Elon] Musk for trying to do it. But it also costs something to be up to date with the latest technology, “said Steiner.