Keys
Road Trips

Overseas Highway: Driving Florida’s 100-Mile Bridge to Key West

February 19, 2026 3 min read 7 views

The Overseas Highway is unlike any road in America. For 113 miles, US Route 1 hops across 42 bridges connecting a chain of coral and limestone islands from mainland Florida to Key West, with nothing but turquoise water on both sides. The Seven Mile Bridge alone — a ribbon of concrete stretching across open ocean — is one of the most extraordinary stretches of highway ever built.

Route overview

The Overseas Highway begins at Florida City, south of Miami, and ends at Key West. The drive follows the route of Henry Flagler’s Overseas Railway, completed in 1912 and destroyed by a hurricane in 1935. The current highway, completed in 1938, incorporated many of the railway’s bridges and causeways. Mile markers count down from MM 126 near Florida City to MM 0 in Key West, and locals use these markers as addresses — a restaurant “at MM 81” is a more precise location than a street name.

Quick facts

Length
113 miles (181 km)
Bridges
42 bridges total
Driving Time
3.5–4 hours nonstop
Best Season
December–May
Speed Limit
45 mph most sections
Tolls
None

Key stops along the way

Key Largo (MM 106–91)

The first and largest Key. John Pennekamp Coral Reef State Park offers snorkelling and glass-bottom boat tours over the only living coral reef in the continental US. The underwater Christ of the Abyss statue is visible through clear water from a boat. Key Largo is also the dive capital of the Keys — dozens of operators run trips to nearby reef and wreck sites.

Islamorada (MM 90–72)

The “Sport Fishing Capital of the World.” Even if you don’t fish, Robbie’s Marina is worth a stop to hand-feed massive tarpon from the dock — they leap out of the water to grab fish from your hands. Theater of the Sea, one of the oldest marine parks in the world, offers dolphin encounters. The restaurants here serve some of the freshest seafood in the Keys.

Seven Mile Bridge (MM 47–40)

The centrepiece of the entire drive. The modern Seven Mile Bridge runs parallel to the original Flagler-era bridge, which you can see crumbling gracefully beside you. Driving across open ocean for seven uninterrupted miles, with water visible in every direction and nothing but a low railing between you and the Atlantic, is a genuinely unique American driving experience. The old bridge is partially open for walking and cycling — access from the Marathon end.

Bahia Honda State Park (MM 37)

Consistently rated among the best beaches in the United States. The sand is soft, the water is clear, and the snorkelling off the beach is excellent. The park has camping and picnic facilities. The old Bahia Honda Bridge towers over the park and is an impressive sight — you can walk partway across for panoramic views.

Key West (MM 0)

The end of the road — literally the southernmost point in the continental US. Key West is a world unto itself: pastel-coloured Victorian houses, roaming chickens, Duval Street nightlife, and a sunset celebration at Mallory Square every evening. Visit the Ernest Hemingway Home (and its famous six-toed cats), the Harry S. Truman Little White House, and Fort Zachary Taylor State Park for the island’s best beach.

Budget breakdown (per person per day)

Expense Budget Mid-Range
Gas $15–$20 $15–$20
Accommodation $60–$100 (off-season) $150–$300 (peak)
Food $30–$50 $60–$100
Activities $10–$30 $40–$80
Daily total $115–$200 $265–$500

Timing tip: The Keys have only one road in and one road out. Weekend traffic heading south on Friday evenings and returning north on Sundays can be brutal — expect 2+ hour delays at the top of the Keys. Travel midweek if possible, or leave Miami before 8 AM on Fridays to beat the rush.

Frequently asked questions

Can I do the Overseas Highway as a day trip from Miami?
It’s possible but exhausting. The drive alone takes 7–8 hours round trip, leaving minimal time in Key West. A much better option is an overnight stay in Key West or Islamorada, allowing you to enjoy the drive at a relaxed pace and experience the Keys after dark.
When is hurricane season in the Keys?
Officially June 1 through November 30, with the highest risk from August through October. The Keys are particularly vulnerable to hurricanes due to their low elevation. Monitor forecasts and heed evacuation orders — the single road out can gridlock quickly when a storm approaches.
Is Key West expensive?
Yes, especially for accommodation. Hotel rates during peak season (December–April) regularly exceed $300 per night. Budget travellers can save by staying in Marathon or Islamorada and day-tripping to Key West. Camping at Bahia Honda State Park is the most affordable Keys accommodation but books up months in advance.
B
Back Road Boys Team
We're a crew of road trip addicts, scenic drive hunters, and back road explorers. We drive the roads so you know which ones are worth your time.
Keep driving
Related roads
route 66
Road Trips
Route 66: The Complete 2,448-Mile Road Trip Guide (2026 Centennial Edition)

Leave a Reply

Your email address will not be published. Required fields are marked *

The Sunday Drive

One email. Every Sunday. The week's best drives, gear deals, and hidden gems. Join 12,000+ road lovers.