The World’s Longest Suspension Bridge Is History in the Making

After 2,000 years of political and technical hitches, Italy says it’s finally ready to connect Sicily to the mainland.

The Romans tried it first, in 250 BC, to transport 100 elephants captured in battle from Palermo, on the island of Sicily, to Rome. According to the Greek historian Strabo, they used empty barrels and wooden planks to build a temporary bridge across the Strait of Messina, a 3.2-kilometer-wide waterway buffeted by strong currents and winds. The elephants made it to Rome, but history doesn’t record if they did so by bridge.

More than two millennia later, the idea of a bridge across the strait might be closer than ever to realization. After decades of political and technical debate, the Italian government may finally sign off on building the world’s longest suspension bridge. 

“I am cautiously optimistic,” says Giuseppe Muscolino, a professor of engineering at the University of Messina, who was part of a governmental scientific committee on the bridge until 2012. “But all will be decided in the next few months.”

The idea of connecting Sicily to what Sicilians often call “the Continent” is as symbolic as it is practical. Here, in the country’s deep south, high unemployment and poverty rates are in contrast with the relative prosperity of the north. 

“Since Italy was united in 1861, the bridge has been hailed as the savior of the rural south, to bring it in step with the industrialized north and the rest of Europe,” says Aurelio Angelini, a professor of sociology at the University of Palermo and author of The Mythical Bridge on the Strait of Messina. However, the idea has long been opposed by locals on both sides—on political, economic, and environmental grounds. But also, Angelini says, because of resistance to change. “Sicilians and Calabrians are divided, but the majority is against the bridge. Some don’t want to give up traversing by ferry, because anthropologically that is what’s always represented the connection to the Continent,” he says.

The first modern engineering study into a crossing was made in 1866. Engineers decided that a bridge wouldn’t be feasible and proposed an underwater tunnel. In 1876, then minister of public works Giuseppe Zanardelli declared: “Above or below the waves, Sicily must be united to the Continent.” But the tunnel was deemed too expensive and complex, and instead efforts were put into starting a ferry service, which began in 1896.

The bridge returned to public discourse in 1950, after the popular weekly magazine Tempo published an article titled “The World’s Longest Bridge.” Geological surveys were conducted, and then in 1969 the government launched an international competition to design a crossing. There were 143 submissions, of which—confusingly—six were declared winners, ranging from an underwater tunnel to a suspension bridge with five spans. None made it past the conceptual stage.

It wasn’t until the 1990s that a definitive design was agreed upon—a single-span suspension bridge. That’s also when the project morphed into a political issue, after Silvio Berlusconi, a media mogul turned politician—infamous for his “bunga bunga” parties and describing Barack Obama as “tanned”—made the bridge a core election pledge. When he was elected as prime minister in a center-right coalition in 2001, Berlusconi had the project approved and financed, only to have it shut down by his left-wing political opponents after he lost the following general election in 2006. 

Berlusconi was reelected as prime minister in 2008 and revived the project, which was once again approved three years later—though the price had risen from €6.16 billion ($6.72 billion) to €8.5 billion. But shortly after, amid the backdrop of an acute debt crisis in the Euro zone, Berlusconi lost his majority and resigned. His successor, Mario Monti, a respected technocrat, canceled the project a final time in 2013.

Now, the same project has been resurrected by the current government, which in mid-March approved a decree paving the way for the construction of the bridge. This time it’s championed by Matteo Salvini, deputy PM and leader of the populist League party—with support from Berlusconi, now 86, who wrote, “They won’t stop us this time” in an Instagram post on the day the decree was signed.

One of the reasons the project keeps getting revived is that there are so many people profiting from the work of planning for it, according to Nicola Chielotti, a lecturer in diplomacy and international governance at the Loughborough University in London: “They constantly spend money on it, even if it never materializes, and there are some interest groups who are happy to capture that money.” 

Salvini himself has acknowledged that “it’s less expensive to build the bridge than to not build it.”

Another issue, Chielotti adds, is that the project is a useful political pawn for a government that has so far been quiet on some key electoral promises, such as tax reform and an aggressive stance towards international finance.

But the project’s strong politicization—which has resulted mainly in support from the right and opposition from the left—might also be a case of “infrastructure populism,” according to Angelini. “The rhetoric around the bridge is oozing nationalism,”  he says, “and the idea is seen as a symbol of Italy’s grandeur, or the ability to build a bridge longer than anyone ever has.”

The current design for the crossing is a single-span suspension bridge with a length of 3,300 meters. That’s 60 percent longer than the Canakkale Bridge in Turkey, currently the world’s longest suspension bridge, which spans 2,023 meters. With pylons towering in at 380 meters (1,250 feet), the Messina Strait bridge would also be the world’s tallest by structural height, edging out the Millau Viaduct in France, which is 342 meters tall. It would be able to carry 6,000 road vehicles per hour and 200 trains per day, and since the span would be 65 meters above the water, naval traffic would be able to pass undisturbed beneath it. 

Travel time by train between the island and the mainland—currently around two hours including the ferry journey–would be cut to under 10 minutes, bringing the nearly 5 million people who live on Sicily much closer to the rest of Italy. 

Previous plans were for three spans, Muscolino says, with two pylons built in the sea, each sunk between 80 and 100 meters below sea level. These would have been unworkable, given the strong currents in the strait, and would have created a risk to shipping.

“The single span has the advantage that the pylons are built on land. The only issue could be the length, which at over 3 kilometers is certainly something new. The main problem is the wind, but the design has been perfected in the wind tunnel, and I’m confident that it can be built safely and successfully,” Muscolino says.

Construction could take between six and 10 years, according to Muscolino. But Enzo Siviero, an engineer and bridge designer who has long been a vocal supporter of the project, believes it could take even less: “As little as five years—it just depends on how much they want to spend,” he says, citing the example of the Saint George Bridge in Genoa. It was built during the pandemic in just a year and a half by working around the clock, to replace a highway viaduct that had collapsed, killing 43 people. “If they worked like that, it could be done in three and a half years.”

Siviero believes that most of the work done for the project canceled in 2013 is still valid. “It was already based on very restrictive regulations,” he says. “Some of the building technologies and materials will need to be updated, especially the cables, and there is some more work to be done on the architectural quality of the new infrastructure on land, which was not up to the standard of the bridge itself. But all of this can take just a few months. The project is highly doable.”

He agrees that a single-span suspension bridge is the only logical design choice, with wind being the main risk factor. “Wind could sway the bridge up to 4 or 5 meters,” he says. “If it gets too severe, vehicle access might need to be closed for a few hours, but that kind of event happens every five or 10 years, and it usually stops ferry traffic too,” he says.

Because suspension bridges are naturally flexible, there is less concern regarding earthquakes, even though this is a highly seismic area. In 1908, a magnitude 7.1 earthquake almost destroyed Messina and killed more than 80,000 people. However, a suspension bridge would be safe, according to Giovanni Barreca, a geologist at the University of Catania. “There is a fault line here, making Sicily and Calabria move away from each other by 3.5 millimeters a year,” he says, “but the bridge would have its pylons on the same side, so from a geological and technical standpoint, the project is doable.”

The biggest objection to the bridge might be environmental. Even though Salvini billed the project as “the greenest in the world,” environmental organizations have long opposed it.

“We’re still at a stage where there is no evidence that this is feasible economically, technically, and environmentally,” says Dante Caserta, vice president of the Italian branch of the World Wildlife Fund.

The Messina Strait also sits across two environmentally protected zones, Caserta says, which are crucial to the migratory movements of seabirds and sea mammals.

The WWF is also critical of the project’s economics. “For 30 years we’ve done conceptual elaborations that led nowhere but cost Italian taxpayers €312 million,” Caserta says, adding that the overall cost estimate of €8.5 billion euros from 2011 is destined to rise due to the increased prices of materials and inflation.

The bridge would need to be built between the two closest points in the Strait, which are not where the current ferry lines depart from. That means new roads would have to be built on both sides of the strait. Those works could make up half the overall cost of the project, according to Muscolino.

Caserta says it’s not clear that the economics support the cost. “There would not be enough traffic to pay for the project through tolls, because over 75 percent of the people who cross the strait do so without a car,” he says, “so doing all this just to shave off 15 minutes doesn’t make sense, especially because it connects two areas with severe infrastructure problems.” 

Nevertheless, Salvini has already promised that construction will start by the summer of 2024. Will that be the moment the “mythical” bridge will finally become a reality? “This government is in an advantageous position, because the project already exists on paper. However, they are still lacking an executive plan, so claims that construction will start in 2024 are dubious,” says Angelini.

“The bridge has no real connection to the social and economic interests of the country, and people and goods are already moving through other means,” he adds. “I think the chances of ever seeing it built are slim.”

The World’s Longest Suspension Bridge Is History in the Making

(May require free registration to view)