Even if you’ve never ventured outside of Orange County or the confines of Walt Disney World Resort, there’s still a good chance you’ve traversed Florida’s most characteristic type of roadway: the causeway.

A pancake-flat peninsula flecked with lakes and sporting the longest coastline in the contiguous United States, Florida seems a natural place for an abundance of thoroughfares that, by their most basic definition, are raised paved roads, tracks or paths — usually earthen and often man-made — across bodies of water or wetlands.

Here’s where things get a bit confusing. In Florida, the word causeway is frequently applied to thoroughfares that consist of a combination of raised roads and multiple bridges, linked by narrow strips of land or small islands. Most often, you’ll cross this type of causeway traveling from the Floridian mainland to its barrier islands. The San Carlos Bay-spanning Sanibel Causeway, the Venetian Causeway in Miami-Dade County and the Courtney Campbell Causeway, which stretches nearly 10 miles across the northern section of Tampa Bay, are just three heavily traversed examples.

And then there’s the Overseas Highway, which has 42 bridges and too many causeways to count.

Vintage postcard illustration of Florida's Overseas Highway A vintage postcard depicts the old Seven Mile Bridge, originally a rail bridge built in 1912, and Pigeon Key. (Photo: Florida Keys--Public Libraries/flickr)

While some might consider it a causeway in its entirety as it follows the familiar causeway-bridge-causeway-bridge-causeway pattern, nobody really refers to the 113-mile-long Overseas Highway as one. Carrying U.S. Route 1 through the Florida Keys from mainland Florida to its southern terminus in Key West, the so-called "Highway That Goes to the Sea" is the grand dame of scenic drives, the prettiest place in the world to be stuck in bottleneck traffic and the most transcendent stretch of pavement in the Lower 48. There’s nothing else quite like it.

Alongside such fabled roads including Natchez Trace Parkway and the Blue Ridge Parkway, the historic Overseas Highway is one of a select few National Scenic Byways designated as an All-American Road. It’s among the best of the best, the most scenic of scenic drives.

It’s also arguably one of the more surreal All-American roads. On a clear day, driving southbound on the Overseas Highway is akin to gliding above the open ocean into infinity. Just imagine being sandwiched between blue skies and turquoise waters that stretch forever as you charge toward what feels like the end of the Earth (or, in reality, the southernmost point in the contiguous United States). A drive on the Overseas Highway makes anything seem possible.

An empty Overseas Highway passing through Marathon, Florida, following Hurricane Irma A rare sight: The Overseas Highway is eerily empty as it passes through the sports fishing destination of Marathon following Hurricane Irma. (Photo: Angel Valentin/Getty Images)

But as evidenced before and in the aftermath of Hurricane Irma, the Overseas Highway isn’t just an otherworldly artery that enables motorists to island-hop through a tropical wonderland like a real-life magic carpet ride, to which it's often compared. It also functions as an asphalt lifeline, the only road in and out of the Florida Keys, an archipelago or roughly 1,700 coral and limestone islands. Without the Overseas Highway, the islands and the 70,000-some people who call a small number of them home would be severed from the mainland save for transport by water or by air. It was along the Overseas Highway that a mandatory mass evacuation was carried out ahead of Irma and, days later, residents and business owners slowly trickled back to assess the devastation.

Now that debris has been cleared from its causeways and its bridges have been deemed structurally sound and safe for travel, it’s clear that the Overseas Highway has weathered the storm. The Keys, however, have weeks, months, even years of recovery ahead.

As a tribute to the Florida Keys and its beloved scenic byway, here’s the fascinating story of a shining — and incredibly fun to drive on — testament to American ingenuity. Let’s hope that visitors who have never experienced this preternaturally beautiful slice of paradise will be able to make that storied drive someday soon.

A historic sign at the start of Florida's Overseas Highway A tropical paradise that you can drive to: Photographed in 1961, marking the start of the southernmost stretch of U.S. Highway 1, which begins near the Canadian border in Fort Kent, Maine. (Photo: Florida Keys--Public Libraries/flickr)

The Storm of the (early 20th) Century

It was a hurricane of all things that gave way to the creation of the Overseas Highway.

While individual segments of the "original" highway date to the mid-1920s with the construction of State Route 4A, the present day Overseas Highway didn’t come about until the late 1930s following the catastrophic Labor Day Hurricane of 1935, which, to this day, remains the strongest most intense hurricane to make landfall in the United States.

The storm claimed over 400 lives, including a large number of World War I veterans and their families who were living at three Federal Emergency Relief Administration-operated veteran work camps located on the Florida Keys.

The job at hand for the vets? To construct a complete and continuous modern highway from the mainland to Key West that would help alleviate pressure on a struggling, sluggish ferry service. The idea was that the new toll roads would eventually render the ferry system obsolete.

Florida's first Overseas Highway circa 1940 In the early years, the Overseas Highway (pictured here in 1940) consisted of winding dirt roads and rickety wooden bridges. Although scenic, it was more white-knuckle than anything. (Photo: Florida Keys--Public Libraries/flickr)

Writes Jerry Wilkinson in a “History of the Overseas Highway”:

The ferry service was barely adequate. It had a limited capacity, was slow, unreliable, inconvenient and relatively expensive for the service it provided. Often they would run aground, or be delayed due to low tides and shallow water. One ferry captain commented that there was not quite enough water for swimming and too much for farming. Key West was not satisfied. Plans were begun to bridge the water gaps for vehicular traffic to eliminate the ferries.

On Sept. 2, 1935, the mother of all hurricanes hit the Keys. Nearly all work completed or nearly completed to transform State Route 4A into a continuous, non-segmented highway was destroyed. Just off of Lower Matecumbe Key, near mile marker 73, is a small island that was dredged as part of a never-realized bridge that was under construction when the storm hit. The island is now known as Veteran’s Key. In addition to the island, the unfinished bridge’s eight piers remain as a haunting memorial to the veterans who lost their lives in the storm.

Vintage photograph of opening of Florida East Coast Railway, Key West extension, 1912 Best known as the Overseas Railroad, the Key West Extension of the Florida East Coast Railway put the Keys, long accessible only by water, on the map. (Photo: Wikimedia Commons)

When life gives you defunct railway lines ...

In addition to wiping out much of old State Route 4A, the Labor Day Hurricane of 1935 also heavily damaged the one reliable mode of transport in and out of the Keys: the Overseas Railroad.

An extension of the Florida East Coast Railway (FEC), the Overseas Railroad was completed in 1912 and, unlike any existing roads, stretched all the way from mainland Florida to Key West, the state’s most populous city at the time. A hugely complex and expensive undertaking that many critics believed to be impossible to complete, work began on the Overseas Railroad in 1905 as the pet project of Henry Flagler, a Gilded Age oilman-turned-resort developer. Hailing from New York, Flagler was instrumental in transforming the east coast of Florida into the vacation destination that it is today.

Vintage image of Overseas Railroad Although popular during its relatively short lifespan, the Overseas Railroad was ultimately written into history as an ill-fated marvel of early 20th century engineering that, in the end, succumbed to Mother Nature. Following the Labor Day Hurricane of 1935, the financially trouble FEC decided not to rebuild damaged and wholly destroyed sections of the line, leaving the Keys, once again, accessible only by boat.

Following the shuttering of the Overseas Railway, the state of Florida saw a rare opportunity. Although its railbeds were damaged beyond repair by the hurricane, the railway’s most crucial infrastructure, including its bridges and formidable arch viaducts, survived the storm largely intact. And so the state purchased the railroad’s right of way from the FEC for a sum of $640,000 and embarked on an ambitious rail-to-road conversion project that would, at long last, link the disconnected sections of State Route 4A to form a complete highway.

Vintage photograph of Florida's Overseas Railroad (1912-1935) A 1928 photograph of Florida's Overseas Railroad, which was ultimately replaced with the Overseas Highway in the late 1930s. (Photo: Wikimedia Commons)

Work retrofitting the old railway bridges — most notably, the iconic and still-standing Bahia Honda Rail Bridge that links Bahia Honda Key with Spanish Harbor Key — into automobile bridges in the Middle Keys wrapped up in 1938. That year, the now-continuous highway was rechristened as the southernmost stretch of U.S. Route 1. The first incarnation of the current Overseas Highway was officially born.

As Wilkinson writes in his "History of the Overseas Highway": “The Gibraltar of the South [Key West] had a usable vehicle artery to and from the mainland.”

Improvements and modifications on the Overseas Highway, which still incorporated large segments of old State Route 4A, continued through the first half of the 20th century. This work, particularly in the Upper and Lower Keys, picked up steam during World War II when the U.S. Navy, which maintained an air station on Boca Chica Key near Key West, concluded that the existing highway — filled with “many wooden bridges and sharp turns,” to quote Wilkinson — was inadequate for its needs. And so, existing bridges were upgraded and routes were reconfigured as part of an extensive overhaul that, in lieu of building roads atop just part of the old railway, incorporated the FEC right of way in its entirety.

On July 2, 1944, the Overseas Highway was dedicated (again) in a ceremony that Wilkinson notes was “much larger” than when it opened in 1938.

Vintage postcard of Bahia Honda Bridge, Overseas Highway, Florida Following the closure of the Overseas Railroad, many rail bridges like the Bahia Honda Bridge, pictured in this vintage postcard, were retrofitted to accommodate cars. (Image: Florida Keys--Public Libraries /flickr)

Wider roads, bigger bridges

As Key West-bound sun-worshippers descended on the once-sleepy Florida Keys in even greater numbers during the latter half of the 20th century, work on improving the Overseas Highway to accommodate an increase in motor traffic began in earnest. With a focus on lane expansion projects, Wilkinson refers to the highway from 1944 though 1978 as being in an “almost continuous maintenance period.” Another noteworthy event from this period came in April 1954 when tolls — $1 per vehicle and driver plus a quarter for each additional passenger — for traveling on the highway were banished following a "scandal over inappropriate revenue use."

From 1978 though the early 1980s, the Overseas Highway entered a period of dramatic reinvention when 37 bridges, most of them old FEC railway bridges dating back to the early 1900s, were replaced with wider, stronger and heavier spans built specifically for automobile traffic. After years of service, the retrofitted rail bridges, many of them in rather rough condition, were retired.

Seven Mile Bridge, Florida Keys Completed in 1982, the Seven Mile Bridge, which links the Middle Keys to the Lower Keys, runs alongside an old rail-turned-automobile bridge of the same name. (Photo: Karen Bleier/AFP/Getty Images)

In 1982, the bridge that’s now considered the crown jewel of the Overseas Highway, the Seven Mile Bridge, opened to traffic. Crossing Moser Channel to connect Little Duck Key in the Lower Keys to Knight’s Key, part of the city of Marathon in the Middle Keys, this $45 million prestressed concrete box-girder span was considered a feat of engineering and among the world’s longest bridges when completed. (Technically, it’s just shy of seven miles: 35,862 feet or 6.79 miles.)

As is the case with several other modern vehicular bridges along the Overseas Highway, the old Seven Mile Bridge Seven Mile Bridge — completed in 1912 as part of the Overseas Railroad and retrofitted in the late 1930s to accommodate automobiles — still stands alongside it. After the new bridge opened to traffic, a 2.2-mile-long section of the old bridge spanning from Knight’s Key to Pigeon Key remained open as a popular fishing pier and wildly popular sunset-watching spot accessible to pedestrians and cyclists.

A view from the road, Overseas Highway, Florida There's nothing else quite like a drive on the Overseas Highway (preferably when traffic is light and the sun is shining). (Photo: Lucas Klappas/flickr)

The bridge, listed on the National Register of Historic Places, was closed inits entirety in July 2016 as part of a $77 million restoration scheme. It’s due to remain closed until 2021 when it reopens as one of the country’s most spectacular linear parks. (Also in the works for those who would rather hike or bike, not drive, across the archipelago is the Florida Keys Overseas Heritage Trail, a 106-mile paved path set along the old Overseas Railroad route that, when completed, will stretch from Key Largo to Key West as the southernmost section of the East Coast Greenway.)

It’s unclear how the raggedy but beloved old Seven Mile Bridge fared during Hurricane Irma but as Kelly McKinnon, executive director of the Pigeon Key Foundation, relayed to the Florida Rambler in 2013: “The new bridge will go down before the old one does. It’s been there for 100 years; it was made to last. The new one was just built by the lowest bidder.”

Emergency Vehicles driving Florida's Overseas Highway following Hurricane Irma In the immediate aftermath of Hurricane Irma, only emergency vehicles were allowed to access the Overseas Highway, a heavily traveled National Scenic Byway. (Photo: Joe Raedle/Getty Images)

The road to recovery

On Sept. 13, three days after Irma made landfall at Cudjoe Key, the Miami Herald reported that all 42 bridges along the Overseas Highway had been inspected by authorities and were deemed safe for travel. Causeways that had flooded or been washed away during the storm were also deemed passable. Still, only the less-harder-hit Upper Keys were open to anxious returning residents and business owners as large swaths of the Lower and Middle Keys remained without electricity or cell phone service.

On Sept. 18, the Herald reported that the Overseas Highway, including parts of the road south of the Seven Mile Bridge, had reopened in its entirety to vehicular traffic. Neighborhoods in more devastated areas remain off limits indefinitely. Highway access aside, the Keys — from mile marker 107 in Key Largo to mile marker 0 in Key West — will remain temporarily closed to tourists as recovery efforts and repairs to infrastructure continue.

Mile marker 33 in Big Pine Key, Florida Mile marker 33 as seen from the Overseas Highway in Big Pine Key, an island known for its green iguanas and native endangered deer population. (Photo: Big Pine Key Fishing Lodge/flickr)

There is, however, a light at the end of the proverbial highway.

Conde Nast Traveler reports that Key West, the pastel-hued epicenter of tourism on the Florida Keys, plans to reopen to visitors by Oct. 20, just in time for Fantasy Fest, a 10-day, pre-Halloween bacchanalia that’s been held every year since 1979. There’s no way that Key West, no matter how battered and bruised by Irma, would cancel this booze-drenched, body paint-heavy celebration of island life. Like in post-Katrina New Orleans, the party in Key West, an unbreakable town that's lifeblood depends on a constant flow of out-of-towners, will most certainly go on.

In the meantime, it’s not too premature to start making future travel plans to the Florida Keys. While the islands remain off-limits to visitors for now, the scenic drive to end all scenic drives isn’t going anywhere. That said, perhaps it's not such a terrible idea to bring back the toll booths for a while ... anything to help get the Keys back on their feet. The Highway That Goes to the Sea is one road that could most certainly get away with charging admission.

Inset image of Overseas Railroad: Wikimedia Commons

Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.