There are 42 bridges along the Overseas Highway in the Florida Keys.
The Overseas Highway stretches 113 miles (182 km) from Key Largo to Key West, supported by 42 bridges that leap between the coral and limestone islands of the Florida Keys. The longest is the Seven Mile Bridge, which spans 6.8 miles (11 km) and links the Middle Keys to the Lower Keys. These bridges cross the Atlantic Ocean, Florida Bay, and the Gulf of Mexico, offering travelers a rare chance to drive over open water for miles at a stretch. The highway is part of U.S. Route 1 and serves as the only road connection between the mainland and Key West, Florida’s southernmost city.
What’s the geographic layout of the Florida Keys?
The Florida Keys form a 125-mile-long arc of tropical islands curving southwest from near Miami into the Gulf of Mexico and the Straits of Florida.
The Florida Keys form a 125-mile-long (201 km) arc of tropical islands curving southwest from near Miami into the Gulf of Mexico and the Straits of Florida. This island chain is the longest coral reef system in the continental United States and lies just 90 miles (145 km) north of Cuba. The Overseas Highway, completed in stages between 1912 and 1938, transformed these scattered keys into a continuous route accessible by car. It remains one of the most scenic drives in the world, with views of turquoise waters, mangrove forests, and marine life. The highway’s bridges not only connect communities but also reflect the region’s history of innovation in building over open water.
What are the key details about the bridges?
The Overseas Highway includes major bridges like the Seven Mile Bridge, Bahia Honda Bridge, and Long Key Bridge, each with distinct lengths and histories.
| Bridge Name |
Length |
Location |
Year Completed |
Notes |
| Seven Mile Bridge (New) |
6.8 miles (11 km) |
Between Knight’s Key and Little Duck Key |
1982 |
Replaced original bridge; open to pedestrians on a 2.2-mile segment |
| Old Seven Mile Bridge |
6.8 miles (11 km) |
Same route |
1912 |
Closed to traffic; walking access limited to 2.2 miles |
| Bahia Honda Bridge |
0.7 miles (1.1 km) |
Bahia Honda Key |
1938 |
Part of original Overseas Railroad; popular for snorkeling |
| Long Key Bridge |
2.8 miles (4.5 km) |
Between Long Key and Fiesta Key |
1940 |
Replaced earlier structure; now carries southbound lanes |
| Channel 5 Bridge (Matecumbe) |
0.5 miles (0.8 km) |
Upper Matecumbe Key |
1938 |
Links Upper and Lower Matecumbe Keys |
| Pigeon Key Bridge |
200 ft (61 m) |
Pigeon Key |
1912 |
Original railroad bridge; now pedestrian access only |
As of 2026, the entire Overseas Highway is maintained by the Florida Department of Transportation (FDOT). The water beneath the bridges averages 7 feet (2.1 m) deep within 3 miles of shore, deepening to over 20 feet (6 m) in channels between keys. The shallow reefs and seagrass beds support diverse marine life, including parrotfish, rays, and sea turtles. The highway carries approximately 2 million vehicles annually, with peak traffic from December through April.
Why were these bridges built in the first place?
The bridges originated from railroad tycoon Henry Flagler’s vision for an “overseas railroad” in the early 1900s, later repurposed into a highway after a 1935 hurricane.
The idea of connecting the Keys by bridge dates to the early 1900s, when railroad tycoon Henry Flagler envisioned a “railroad that went to sea.” Construction began in 1905, and by 1912, the Overseas Railroad reached Key West—including the original Seven Mile Bridge. The Florida East Coast Railway operated the line until a 1935 hurricane destroyed much of the track. The state then converted the surviving bridges and embankments into the Overseas Highway, completed in 1938. The old railroad bridges, including the iconic Long Key Viaduct, were later refurbished for vehicle traffic. Today, the Seven Mile Bridge remains an engineering landmark and a symbol of resilience, rebuilt after damage from Hurricane Irma in 2017 and re-opened to traffic in 2019. The abandoned Old Seven Mile Bridge now serves as a fishing pier and walkway, offering panoramic views of the Gulf and Atlantic.
Culturally, the bridges have shaped life in the Keys. They enabled tourism to flourish, especially after the highway was paved in the 1950s. The Florida Keys are home to about 78,000 residents as of the 2025 U.S. Census estimate, with tourism accounting for nearly 50% of local income. The bridges also play a role in marine ecology, as they provide shade and habitat for juvenile fish and crustaceans along their pilings. The Overseas Highway has inspired songs, films, and books, cementing its place in American road-trip lore.
How deep is the water under these bridges?
The water averages 7 feet deep near shore, but drops to over 20 feet in the channels between keys.
As of 2026, the entire Overseas Highway is maintained by the Florida Department of Transportation (FDOT). The water beneath the bridges averages 7 feet (2.1 m) deep within 3 miles of shore, deepening to over 20 feet (6 m) in channels between keys. The shallow reefs and seagrass beds support diverse marine life, including parrotfish, rays, and sea turtles. The highway carries approximately 2 million vehicles annually, with peak traffic from December through April.
What’s the traffic like on the Overseas Highway?
About 2 million vehicles use the highway each year, with the busiest months being December through April.
As of 2026, the entire Overseas Highway is maintained by the Florida Department of Transportation (FDOT). The water beneath the bridges averages 7 feet (2.1 m) deep within 3 miles of shore, deepening to over 20 feet (6 m) in channels between keys. The shallow reefs and seagrass beds support diverse marine life, including parrotfish, rays, and sea turtles. The highway carries approximately 2 million vehicles annually, with peak traffic from December through April.
What’s the best time of year to drive the Overseas Highway?
The ideal window is November through April, when temperatures are mild and rain is scarce.
The Overseas Highway is fully accessible year-round, though summer months (June–September) bring higher humidity, frequent rain, and the risk of tropical storms. As of 2026, tolls are not charged on the highway, but fuel prices are elevated due to transportation costs—expect to pay $4.20–$4.80 per gallon in Key West. The best time to drive is November through April, when temperatures range from 70°F to 85°F (21°C–29°C) and rain is minimal.
Are there any tolls on the Overseas Highway?
No tolls are charged on the Overseas Highway as of 2026.
The Overseas Highway is fully accessible year-round, though summer months (June–September) bring higher humidity, frequent rain, and the risk of tropical storms. As of 2026, tolls are not charged on the highway, but fuel prices are elevated due to transportation costs—expect to pay $4.20–$4.80 per gallon in Key West. The best time to drive is November through April, when temperatures range from 70°F to 85°F (21°C–29°C) and rain is minimal.
What should drivers know about fuel costs in the Keys?
Fuel prices in Key West typically run between $4.20 and $4.80 per gallon due to transportation costs.
The Overseas Highway is fully accessible year-round, though summer months (June–September) bring higher humidity, frequent rain, and the risk of tropical storms. As of 2026, tolls are not charged on the highway, but fuel prices are elevated due to transportation costs—expect to pay $4.20–$4.80 per gallon in Key West. The best time to drive is November through April, when temperatures range from 70°F to 85°F (21°C–29°C) and rain is minimal.
What are the top stops along the Overseas Highway?
Key highlights include John Pennekamp Coral Reef State Park, Islamorada’s fishing charters, Marathon’s Crane Point Museum, Big Pine Key’s Key deer refuge, and Key West’s Ernest Hemingway House.
Notable stops include:
- Key Largo: Home to John Pennekamp Coral Reef State Park and the only living coral reef in the continental U.S. accessible by snorkelers.
- Islamorada: Known as the “Sportfishing Capital of the World,” with marinas offering charters for tarpon, bonefish, and sailfish.
- Marathon: Features the Crane Point Museum and the old Seven Mile Bridge walking path.
- Big Pine Key: Sanctuary for the endangered Key deer and site of the National Key Deer Refuge visitor center.
- Key West: The southernmost city in the continental U.S., home to Ernest Hemingway’s house, the Southernmost Point buoy, and a vibrant arts scene.
How long does it take to drive from Key Largo to Key West?
Most drivers need 4 hours nonstop, but 6–8 hours is better if you want to explore along the way.
While driving, watch for speed limits (typically 55 mph unless posted), wildlife crossings (especially for Key deer), and sudden changes in weather. The Florida Keys Visitors Bureau recommends allowing at least 4 hours for the drive from Key Largo to Key West, but budget 6–8 hours to enjoy attractions, snorkeling spots, and local seafood. The highway is well-marked with rest areas, gas stations, and emergency call boxes every few miles. Cell service is reliable along most of the route, though coverage can be spotty on some smaller keys.
What wildlife should drivers watch for?
Keep an eye out for Key deer, especially around Big Pine Key, and watch for sudden weather changes.
While driving, watch for speed limits (typically 55 mph unless posted), wildlife crossings (especially for Key deer), and sudden changes in weather. The Florida Keys Visitors Bureau recommends allowing at least 4 hours for the drive from Key Largo to Key West, but budget 6–8 hours to enjoy attractions, snorkeling spots, and local seafood. The highway is well-marked with rest areas, gas stations, and emergency call boxes every few miles. Cell service is reliable along most of the route, though coverage can be spotty on some smaller keys.
Is cell service reliable along the Overseas Highway?
Cell service is generally reliable along most of the route, though it can be spotty on some smaller keys.
While driving, watch for speed limits (typically 55 mph unless posted), wildlife crossings (especially for Key deer), and sudden changes in weather. The Florida Keys Visitors Bureau recommends allowing at least 4 hours for the drive from Key Largo to Key West, but budget 6–8 hours to enjoy attractions, snorkeling spots, and local seafood. The highway is well-marked with rest areas, gas stations, and emergency call boxes every few miles. Cell service is reliable along most of the route, though coverage can be spotty on some smaller keys.
What’s the history behind the Seven Mile Bridge?
The original Seven Mile Bridge opened in 1912 as part of Henry Flagler’s railroad, while the current version was completed in 1982 after Hurricane Irma repairs in 2019.
The idea of connecting the Keys by bridge dates to the early 1900s, when railroad tycoon Henry Flagler envisioned a “railroad that went to sea.” Construction began in 1905, and by 1912, the Overseas Railroad reached Key West—including the original Seven Mile Bridge. The Florida East Coast Railway operated the line until a 1935 hurricane destroyed much of the track. The state then converted the surviving bridges and embankments into the Overseas Highway, completed in 1938. The old railroad bridges, including the iconic Long Key Viaduct, were later refurbished for vehicle traffic. Today, the Seven Mile Bridge remains an engineering landmark and a symbol of resilience, rebuilt after damage from Hurricane Irma in 2017 and re-opened to traffic in 2019. The abandoned Old Seven Mile Bridge now serves as a fishing pier and walkway, offering panoramic views of the Gulf and Atlantic.
Culturally, the bridges have shaped life in the Keys. They enabled tourism to flourish, especially after the highway was paved in the 1950s. The Florida Keys are home to about 78,000 residents as of the 2025 U.S. Census estimate, with tourism accounting for nearly 50% of local income. The bridges also play a role in marine ecology, as they provide shade and habitat for juvenile fish and crustaceans along their pilings. The Overseas Highway has inspired songs, films, and books, cementing its place in American road-trip lore.
How have the bridges impacted marine life?
The bridges provide shade and habitat for juvenile fish and crustaceans along their pilings, supporting local marine ecosystems.
Culturally, the bridges have shaped life in the Keys. They enabled tourism to flourish, especially after the highway was paved in the 1950s. The Florida Keys are home to about 78,000 residents as of the 2025 U.S. Census estimate, with tourism accounting for nearly 50% of local income. The bridges also play a role in marine ecology, as they provide shade and habitat for juvenile fish and crustaceans along their pilings. The Overseas Highway has inspired songs, films, and books, cementing its place in American road-trip lore.
What’s the cultural significance of the Overseas Highway?
The highway has inspired songs, films, and books, becoming a symbol of American road-trip culture and tourism in the Keys.
Culturally, the bridges have shaped life in the Keys. They enabled tourism to flourish, especially after the highway was paved in the 1950s. The Florida Keys are home to about 78,000 residents as of the 2025 U.S. Census estimate, with tourism accounting for nearly 50% of local income. The bridges also play a role in marine ecology, as they provide shade and habitat for juvenile fish and crustaceans along their pilings. The Overseas Highway has inspired songs, films, and books, cementing its place in American road-trip lore.
Edited and fact-checked by the MeridianFacts editorial team.
